From 4350f484da9132cb8f7f6b4e256f8678c0959688 Mon Sep 17 00:00:00 2001
From: Abubakar Meigag <113248042+Abubakar-Meigag@users.noreply.github.com>
Date: Wed, 11 Mar 2026 17:31:33 +0000
Subject: [PATCH 01/24] Fix expected output in sed exercise instructions (#353)

Fix expected output: change 'with' to 'wIth' in sed exercise
instructions
---
 individual-shell-tools/sed/script-01.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/individual-shell-tools/sed/script-01.sh b/individual-shell-tools/sed/script-01.sh
index 3eba6fa..d592970 100755
--- a/individual-shell-tools/sed/script-01.sh
+++ b/individual-shell-tools/sed/script-01.sh
@@ -4,4 +4,4 @@ set -euo pipefail
 
 # TODO: Write a command to output input.txt with all occurrences of the letter `i` replaced with `I`.
 # The output should contain 11 lines.
-# The first line of the output should be: "ThIs Is a sample fIle for experImentIng with sed.".
+# The first line of the output should be: "ThIs Is a sample fIle for experImentIng wIth sed.".

From 743e4911fb9de80d1c5934bdc857738d9f60ed7e Mon Sep 17 00:00:00 2001
From: LonMcGregor <3817332+LonMcGregor@users.noreply.github.com>
Date: Mon, 11 May 2026 10:28:21 +0100
Subject: [PATCH 02/24] Automate testing of initial sprints in tools module
 (#472)

* Expected output now in expected folder
* Github action which runs after validation, when Needs Review
* Script that can be run to test locally before push
* Split number sys qs into automatable/manualy checkable

---------

Co-authored-by: l <l>
---
 .github/workflows/validate-pr-metadata.yml    |  57 +++++++-
 .gitignore                                    |   1 +
 .../individual-shell-tools/awk/script-01.sh   |   6 +
 .../individual-shell-tools/awk/script-02.sh   |   6 +
 .../individual-shell-tools/awk/script-03.sh   |   6 +
 .../individual-shell-tools/awk/script-04.sh   |   3 +
 .../individual-shell-tools/awk/script-05.sh   |   6 +
 .../awk/script-06-stretch.sh                  |   1 +
 .../awk/script-07-stretch.sh                  |   6 +
 .../individual-shell-tools/cat/script-01.sh   |   1 +
 .../individual-shell-tools/cat/script-02.sh   |   5 +
 .../individual-shell-tools/cat/script-03.sh   |   3 +
 .../cat/script-04-stretch.sh                  |   5 +
 .../individual-shell-tools/grep/script-01.sh  |   6 +
 .../individual-shell-tools/grep/script-02.sh  |   9 ++
 .../individual-shell-tools/grep/script-03.sh  |   1 +
 .../individual-shell-tools/grep/script-04.sh  |  10 ++
 .../individual-shell-tools/grep/script-05.sh  |   5 +
 .../individual-shell-tools/grep/script-06.sh  |   2 +
 .../individual-shell-tools/grep/script-07.sh  |   3 +
 expect/individual-shell-tools/ls/script-01.sh |   5 +
 expect/individual-shell-tools/ls/script-02.sh |   3 +
 expect/individual-shell-tools/ls/script-03.sh |  11 ++
 expect/individual-shell-tools/ls/script-04.sh |   8 ++
 .../individual-shell-tools/sed/script-01.sh   |  11 ++
 .../individual-shell-tools/sed/script-02.sh   |  11 ++
 .../individual-shell-tools/sed/script-03.sh   |   6 +
 .../individual-shell-tools/sed/script-04.sh   |  11 ++
 .../individual-shell-tools/sed/script-05.sh   |  11 ++
 .../individual-shell-tools/sed/script-06.sh   |  11 ++
 expect/individual-shell-tools/wc/script-01.sh |   1 +
 expect/individual-shell-tools/wc/script-02.sh |   1 +
 expect/individual-shell-tools/wc/script-03.sh |   4 +
 expect/jq/script-01.sh                        |   1 +
 expect/jq/script-02.sh                        |   1 +
 expect/jq/script-03.sh                        |   2 +
 expect/jq/script-04.sh                        |   6 +
 expect/jq/script-05.sh                        |   6 +
 expect/jq/script-06.sh                        |   6 +
 expect/jq/script-07.sh                        |   6 +
 expect/jq/script-08.sh                        |   6 +
 expect/jq/script-09.sh                        |   6 +
 expect/jq/script-10.sh                        |   1 +
 expect/jq/script-11.sh                        |   1 +
 expect/number-systems/Part-1.json             |   1 +
 expect/shell-pipelines/ls-grep/script-01.sh   |  11 ++
 expect/shell-pipelines/ls-grep/script-02.sh   |  10 ++
 expect/shell-pipelines/ls-grep/script-03.sh   |   7 +
 expect/shell-pipelines/ls-grep/script-04.sh   |   1 +
 .../sort-uniq-head-tail/script-01.sh          |   6 +
 .../sort-uniq-head-tail/script-02.sh          |   6 +
 .../sort-uniq-head-tail/script-03.sh          |   3 +
 .../sort-uniq-head-tail/script-04.sh          |   1 +
 .../sort-uniq-head-tail/script-05.sh          |   6 +
 .../sort-uniq-head-tail/script-06.sh          |   2 +
 .../sort-uniq-head-tail/script-07.sh          |   2 +
 expect/shell-pipelines/tr/script-01.sh        |  11 ++
 expect/shell-pipelines/tr/script-02.sh        |  11 ++
 number-systems/Part-1.md                      |  54 +++++++
 number-systems/Part-2.md                      |  22 +++
 number-systems/README.md                      |  65 ---------
 test-sdc.sh                                   | 132 ++++++++++++++++++
 62 files changed, 561 insertions(+), 68 deletions(-)
 create mode 100755 expect/individual-shell-tools/awk/script-01.sh
 create mode 100755 expect/individual-shell-tools/awk/script-02.sh
 create mode 100755 expect/individual-shell-tools/awk/script-03.sh
 create mode 100755 expect/individual-shell-tools/awk/script-04.sh
 create mode 100755 expect/individual-shell-tools/awk/script-05.sh
 create mode 100755 expect/individual-shell-tools/awk/script-06-stretch.sh
 create mode 100755 expect/individual-shell-tools/awk/script-07-stretch.sh
 create mode 100755 expect/individual-shell-tools/cat/script-01.sh
 create mode 100755 expect/individual-shell-tools/cat/script-02.sh
 create mode 100755 expect/individual-shell-tools/cat/script-03.sh
 create mode 100755 expect/individual-shell-tools/cat/script-04-stretch.sh
 create mode 100755 expect/individual-shell-tools/grep/script-01.sh
 create mode 100755 expect/individual-shell-tools/grep/script-02.sh
 create mode 100755 expect/individual-shell-tools/grep/script-03.sh
 create mode 100755 expect/individual-shell-tools/grep/script-04.sh
 create mode 100755 expect/individual-shell-tools/grep/script-05.sh
 create mode 100755 expect/individual-shell-tools/grep/script-06.sh
 create mode 100755 expect/individual-shell-tools/grep/script-07.sh
 create mode 100755 expect/individual-shell-tools/ls/script-01.sh
 create mode 100755 expect/individual-shell-tools/ls/script-02.sh
 create mode 100755 expect/individual-shell-tools/ls/script-03.sh
 create mode 100755 expect/individual-shell-tools/ls/script-04.sh
 create mode 100755 expect/individual-shell-tools/sed/script-01.sh
 create mode 100755 expect/individual-shell-tools/sed/script-02.sh
 create mode 100755 expect/individual-shell-tools/sed/script-03.sh
 create mode 100755 expect/individual-shell-tools/sed/script-04.sh
 create mode 100755 expect/individual-shell-tools/sed/script-05.sh
 create mode 100755 expect/individual-shell-tools/sed/script-06.sh
 create mode 100755 expect/individual-shell-tools/wc/script-01.sh
 create mode 100755 expect/individual-shell-tools/wc/script-02.sh
 create mode 100755 expect/individual-shell-tools/wc/script-03.sh
 create mode 100755 expect/jq/script-01.sh
 create mode 100755 expect/jq/script-02.sh
 create mode 100755 expect/jq/script-03.sh
 create mode 100755 expect/jq/script-04.sh
 create mode 100755 expect/jq/script-05.sh
 create mode 100755 expect/jq/script-06.sh
 create mode 100755 expect/jq/script-07.sh
 create mode 100755 expect/jq/script-08.sh
 create mode 100755 expect/jq/script-09.sh
 create mode 100755 expect/jq/script-10.sh
 create mode 100755 expect/jq/script-11.sh
 create mode 100644 expect/number-systems/Part-1.json
 create mode 100755 expect/shell-pipelines/ls-grep/script-01.sh
 create mode 100755 expect/shell-pipelines/ls-grep/script-02.sh
 create mode 100755 expect/shell-pipelines/ls-grep/script-03.sh
 create mode 100755 expect/shell-pipelines/ls-grep/script-04.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-01.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-02.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-03.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-04.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-05.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-06.sh
 create mode 100755 expect/shell-pipelines/sort-uniq-head-tail/script-07.sh
 create mode 100755 expect/shell-pipelines/tr/script-01.sh
 create mode 100755 expect/shell-pipelines/tr/script-02.sh
 create mode 100644 number-systems/Part-1.md
 create mode 100644 number-systems/Part-2.md
 delete mode 100644 number-systems/README.md
 create mode 100755 test-sdc.sh

diff --git a/.github/workflows/validate-pr-metadata.yml b/.github/workflows/validate-pr-metadata.yml
index 10ef3c7..8ff276f 100644
--- a/.github/workflows/validate-pr-metadata.yml
+++ b/.github/workflows/validate-pr-metadata.yml
@@ -1,9 +1,8 @@
-name: Validate PR Metadata
+name: Validate PR Metadata and Check SDC-Tools Tasks
 on:
-  pull_request_target:
+  pull_request:
     types:
       - labeled
-      - unlabeled
       - opened
       - edited
       - reopened
@@ -16,3 +15,55 @@ jobs:
       - uses: CodeYourFuture/actions/validate-pr-metadata@main
         with:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+
+  test_sdc_tasks:
+    name: Test SDC Tasks
+    runs-on: ubuntu-slim
+    permissions:
+      pull-requests: write
+    if: ${{ github.event.label.name == 'Needs Review' }}
+    steps:
+      - name: checkout base branch
+        uses: actions/checkout@v5
+      - name: Get changed files
+        id: changed-files
+        uses: tj-actions/changed-files@v47.0.5
+      - name: test individual shell tools
+        id: test-individual-shell-tools
+        if: contains(steps.changed-files.outputs.modified_files, 'individual-shell-tools/')
+        run: ./test-sdc.sh individual-shell-tools
+        shell: bash
+      - name: test jq
+        id: test-jq
+        if: contains(steps.changed-files.outputs.modified_files, 'jq/')
+        run: ./test-sdc.sh jq
+        shell: bash
+      - name: test shell-pipelines
+        id: test-shell-pipelines
+        if: contains(steps.changed-files.outputs.modified_files, 'shell-pipelines/')
+        run: ./test-sdc.sh shell-pipelines
+        shell: bash
+      - name: test number-systems
+        id: test-number-systems
+        if: contains(steps.changed-files.outputs.modified_files, 'number-systems/')
+        run: ./test-sdc.sh number-systems
+        shell: bash
+      - name: make output comment
+        if: steps.test-individual-shell-tools.outputs.attempted == 'y' || steps.test-jq.outputs.attempted == 'y' || steps.test-shell-pipelines.outputs.attempted == 'y' || steps.test-number-systems.outputs.attempted == 'y'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ISSUE_URL: ${{ github.event.pull_request.html_url }}
+        run: |
+          gh pr comment $ISSUE_URL --body-file testoutput.txt
+      - name: add appropriate labels
+        if: steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y'
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          ISSUE_URL: ${{ github.event.pull_request.html_url }}
+        run: |
+          gh pr edit $ISSUE_URL --add-label "Complete"
+          gh pr edit $ISSUE_URL --remove-label "Needs Review"
+      - name: fail if not complete
+        if: (steps.test-individual-shell-tools.outputs.attempted == 'y' || steps.test-jq.outputs.attempted == 'y' || steps.test-shell-pipelines.outputs.attempted == 'y') && !(steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y')
+        run: |
+          exit -1
diff --git a/.gitignore b/.gitignore
index 3c3629e..c4234ab 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
 node_modules
+testoutput.txt
diff --git a/expect/individual-shell-tools/awk/script-01.sh b/expect/individual-shell-tools/awk/script-01.sh
new file mode 100755
index 0000000..050f043
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-01.sh
@@ -0,0 +1,6 @@
+Ahmed
+Basia
+Mehmet
+Leila
+Piotr
+Chandra
diff --git a/expect/individual-shell-tools/awk/script-02.sh b/expect/individual-shell-tools/awk/script-02.sh
new file mode 100755
index 0000000..ee7e0fe
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-02.sh
@@ -0,0 +1,6 @@
+Ahmed London
+Basia London
+Mehmet Birmingham
+Leila London
+Piotr Glasgow
+Chandra Birmingham
diff --git a/expect/individual-shell-tools/awk/script-03.sh b/expect/individual-shell-tools/awk/script-03.sh
new file mode 100755
index 0000000..f5d0b1f
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-03.sh
@@ -0,0 +1,6 @@
+Ahmed 1
+Basia 22
+Mehmet 3
+Leila 1
+Piotr 15
+Chandra 12
diff --git a/expect/individual-shell-tools/awk/script-04.sh b/expect/individual-shell-tools/awk/script-04.sh
new file mode 100755
index 0000000..6e95a2f
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-04.sh
@@ -0,0 +1,3 @@
+Ahmed 4
+Basia 6
+Leila 1
diff --git a/expect/individual-shell-tools/awk/script-05.sh b/expect/individual-shell-tools/awk/script-05.sh
new file mode 100755
index 0000000..dd7e1d3
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-05.sh
@@ -0,0 +1,6 @@
+Ahmed 3
+Basia 3
+Mehmet 3
+Leila 1
+Piotr 5
+Chandra 2
diff --git a/expect/individual-shell-tools/awk/script-06-stretch.sh b/expect/individual-shell-tools/awk/script-06-stretch.sh
new file mode 100755
index 0000000..fb1e7bc
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-06-stretch.sh
@@ -0,0 +1 @@
+54
diff --git a/expect/individual-shell-tools/awk/script-07-stretch.sh b/expect/individual-shell-tools/awk/script-07-stretch.sh
new file mode 100755
index 0000000..33ff777
--- /dev/null
+++ b/expect/individual-shell-tools/awk/script-07-stretch.sh
@@ -0,0 +1,6 @@
+Ahmed 15
+Basia 37
+Mehmet 32
+Leila 1
+Piotr 61
+Chandra 18
diff --git a/expect/individual-shell-tools/cat/script-01.sh b/expect/individual-shell-tools/cat/script-01.sh
new file mode 100755
index 0000000..ed7bf7d
--- /dev/null
+++ b/expect/individual-shell-tools/cat/script-01.sh
@@ -0,0 +1 @@
+Once upon a time...
diff --git a/expect/individual-shell-tools/cat/script-02.sh b/expect/individual-shell-tools/cat/script-02.sh
new file mode 100755
index 0000000..769b7e0
--- /dev/null
+++ b/expect/individual-shell-tools/cat/script-02.sh
@@ -0,0 +1,5 @@
+Once upon a time...
+There was a house made of gingerbread.
+It looked delicious.
+I was tempted to take a bite of it.
+But this seemed like a bad idea...
diff --git a/expect/individual-shell-tools/cat/script-03.sh b/expect/individual-shell-tools/cat/script-03.sh
new file mode 100755
index 0000000..f97bd50
--- /dev/null
+++ b/expect/individual-shell-tools/cat/script-03.sh
@@ -0,0 +1,3 @@
+     1	It looked delicious.
+     2	I was tempted to take a bite of it.
+     3	But this seemed like a bad idea...
diff --git a/expect/individual-shell-tools/cat/script-04-stretch.sh b/expect/individual-shell-tools/cat/script-04-stretch.sh
new file mode 100755
index 0000000..6f35e89
--- /dev/null
+++ b/expect/individual-shell-tools/cat/script-04-stretch.sh
@@ -0,0 +1,5 @@
+     1	Once upon a time...
+     2	There was a house made of gingerbread.
+     3	It looked delicious.
+     4	I was tempted to take a bite of it.
+     5	But this seemed like a bad idea...
diff --git a/expect/individual-shell-tools/grep/script-01.sh b/expect/individual-shell-tools/grep/script-01.sh
new file mode 100755
index 0000000..bc96ffe
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-01.sh
@@ -0,0 +1,6 @@
+Doctor: Hello
+Doctor: What's wrong today?
+Doctor: That sounds frustrating. When did this start?
+Doctor: Say "Hi".
+Doctor: You didn't say hello
+Doctor: You're welcome, goodbye
diff --git a/expect/individual-shell-tools/grep/script-02.sh b/expect/individual-shell-tools/grep/script-02.sh
new file mode 100755
index 0000000..bad606e
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-02.sh
@@ -0,0 +1,9 @@
+Doctor: Hello
+Patient: Hello Doctor
+Doctor: What's wrong today?
+Doctor: That sounds frustrating. When did this start?
+Doctor: Say "Hi".
+Doctor: You didn't say hello
+Doctor: You're welcome, goodbye
+Patient: I went to the doctor!
+Spouse: I'm glad you saw the Doctor: did they cure you?
diff --git a/expect/individual-shell-tools/grep/script-03.sh b/expect/individual-shell-tools/grep/script-03.sh
new file mode 100755
index 0000000..ec63514
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-03.sh
@@ -0,0 +1 @@
+9
diff --git a/expect/individual-shell-tools/grep/script-04.sh b/expect/individual-shell-tools/grep/script-04.sh
new file mode 100755
index 0000000..5814afa
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-04.sh
@@ -0,0 +1,10 @@
+Doctor: What's wrong today?
+Doctor: That sounds frustrating. When did this start?
+Doctor: Say "Hi".
+Patient: Hi
+Patient: I seem to be cured!
+Doctor: You're welcome, goodbye
+
+Patient: I went to the doctor!
+Spouse: I'm glad you saw the Doctor: did they cure you?
+Patient: Yes!
diff --git a/expect/individual-shell-tools/grep/script-05.sh b/expect/individual-shell-tools/grep/script-05.sh
new file mode 100755
index 0000000..2ed07ed
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-05.sh
@@ -0,0 +1,5 @@
+Doctor: You didn't say hello
+Patient: I seem to be cured!
+--
+Patient: I went to the doctor!
+Spouse: I'm glad you saw the Doctor: did they cure you?
diff --git a/expect/individual-shell-tools/grep/script-06.sh b/expect/individual-shell-tools/grep/script-06.sh
new file mode 100755
index 0000000..87b3a4f
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-06.sh
@@ -0,0 +1,2 @@
+dialogue-2.txt
+dialogue.txt
diff --git a/expect/individual-shell-tools/grep/script-07.sh b/expect/individual-shell-tools/grep/script-07.sh
new file mode 100755
index 0000000..aed78c6
--- /dev/null
+++ b/expect/individual-shell-tools/grep/script-07.sh
@@ -0,0 +1,3 @@
+dialogue-2.txt:2
+dialogue-3.txt:0
+dialogue.txt:6
diff --git a/expect/individual-shell-tools/ls/script-01.sh b/expect/individual-shell-tools/ls/script-01.sh
new file mode 100755
index 0000000..dd590d6
--- /dev/null
+++ b/expect/individual-shell-tools/ls/script-01.sh
@@ -0,0 +1,5 @@
+child-directory
+script-01.sh
+script-02.sh
+script-03.sh
+script-04.sh
diff --git a/expect/individual-shell-tools/ls/script-02.sh b/expect/individual-shell-tools/ls/script-02.sh
new file mode 100755
index 0000000..bfd087e
--- /dev/null
+++ b/expect/individual-shell-tools/ls/script-02.sh
@@ -0,0 +1,3 @@
+helper-1.txt
+helper-2.txt
+helper-3.txt
diff --git a/expect/individual-shell-tools/ls/script-03.sh b/expect/individual-shell-tools/ls/script-03.sh
new file mode 100755
index 0000000..36acd71
--- /dev/null
+++ b/expect/individual-shell-tools/ls/script-03.sh
@@ -0,0 +1,11 @@
+.:
+child-directory
+script-01.sh
+script-02.sh
+script-03.sh
+script-04.sh
+
+./child-directory:
+helper-1.txt
+helper-2.txt
+helper-3.txt
diff --git a/expect/individual-shell-tools/ls/script-04.sh b/expect/individual-shell-tools/ls/script-04.sh
new file mode 100755
index 0000000..86e7570
--- /dev/null
+++ b/expect/individual-shell-tools/ls/script-04.sh
@@ -0,0 +1,8 @@
+First exercise (sorted newest to oldest):
+helper-3.txt
+helper-1.txt
+helper-2.txt
+Second exercise (sorted oldest to newest):
+helper-2.txt
+helper-1.txt
+helper-3.txt
diff --git a/expect/individual-shell-tools/sed/script-01.sh b/expect/individual-shell-tools/sed/script-01.sh
new file mode 100755
index 0000000..d92b03a
--- /dev/null
+++ b/expect/individual-shell-tools/sed/script-01.sh
@@ -0,0 +1,11 @@
+ThIs Is a sample fIle for experImentIng wIth sed.
+
+It contaIns many lInes, and there are some thIngs you may want to do wIth each of them.
+
+We'll Include some score InformatIon:
+37 AlIsha
+15 Jacob
+7 PIetro
+3 Katya
+
+We also should remember, when we go shoppIng, to get 4 Items: oranges,cheese,bread,olIves.
diff --git a/expect/individual-shell-tools/sed/script-02.sh b/expect/individual-shell-tools/sed/script-02.sh
new file mode 100755
index 0000000..e326bd4
--- /dev/null
+++ b/expect/individual-shell-tools/sed/script-02.sh
@@ -0,0 +1,11 @@
+This is a sample file for experimenting with sed.
+
+It contains many lines, and there are some things you may want to do with each of them.
+
+We'll include some score information:
+ Alisha
+ Jacob
+ Pietro
+ Katya
+
+We also should remember, when we go shopping, to get  items: oranges,cheese,bread,olives.
diff --git a/expect/individual-shell-tools/sed/script-03.sh b/expect/individual-shell-tools/sed/script-03.sh
new file mode 100755
index 0000000..088b17d
--- /dev/null
+++ b/expect/individual-shell-tools/sed/script-03.sh
@@ -0,0 +1,6 @@
+This is a sample file for experimenting with sed.
+
+It contains many lines, and there are some things you may want to do with each of them.
+
+We'll include some score information:
+
diff --git a/expect/individual-shell-tools/sed/script-04.sh b/expect/individual-shell-tools/sed/script-04.sh
new file mode 100755
index 0000000..852fa15
--- /dev/null
+++ b/expect/individual-shell-tools/sed/script-04.sh
@@ -0,0 +1,11 @@
+This is a sample file for experimenting with sed.
+
+It contains many lines, and there are some things you may want to do with each of them.
+
+We'll include some score information:
+37 Alisha
+15 Jacob
+7 Pietro
+3 Katya
+
+We also should remember, when we go shopping, to get 4 items: oranges,cheese,bread,olives.
diff --git a/expect/individual-shell-tools/sed/script-05.sh b/expect/individual-shell-tools/sed/script-05.sh
new file mode 100755
index 0000000..fe4d9d1
--- /dev/null
+++ b/expect/individual-shell-tools/sed/script-05.sh
@@ -0,0 +1,11 @@
+This is a sample file for experimenting with sed.
+
+It contains many lines, and there are some things you may want to do with each of them.
+
+We'll include some score information:
+Alisha 37
+Jacob 15
+Pietro 7
+Katya 3
+
+We also should remember, when we go shopping, to get 4 items: oranges,cheese,bread,olives.
diff --git a/expect/individual-shell-tools/sed/script-06.sh b/expect/individual-shell-tools/sed/script-06.sh
new file mode 100755
index 0000000..d9f950f
--- /dev/null
+++ b/expect/individual-shell-tools/sed/script-06.sh
@@ -0,0 +1,11 @@
+This is a sample file for experimenting with sed.
+
+It contains many lines, and there are some things you may want to do with each of them.
+
+We'll include some score information:
+37 Alisha
+15 Jacob
+7 Pietro
+3 Katya
+
+We also should remember, when we go shopping, to get 4 items: oranges, cheese, bread, olives.
diff --git a/expect/individual-shell-tools/wc/script-01.sh b/expect/individual-shell-tools/wc/script-01.sh
new file mode 100755
index 0000000..d1ad53e
--- /dev/null
+++ b/expect/individual-shell-tools/wc/script-01.sh
@@ -0,0 +1 @@
+19 ../helper-files/helper-3.txt
diff --git a/expect/individual-shell-tools/wc/script-02.sh b/expect/individual-shell-tools/wc/script-02.sh
new file mode 100755
index 0000000..6bd060b
--- /dev/null
+++ b/expect/individual-shell-tools/wc/script-02.sh
@@ -0,0 +1 @@
+3 ../helper-files/helper-3.txt
diff --git a/expect/individual-shell-tools/wc/script-03.sh b/expect/individual-shell-tools/wc/script-03.sh
new file mode 100755
index 0000000..572716a
--- /dev/null
+++ b/expect/individual-shell-tools/wc/script-03.sh
@@ -0,0 +1,4 @@
+  1   4  20 ../helper-files/helper-1.txt
+  1   7  39 ../helper-files/helper-2.txt
+  3  19  92 ../helper-files/helper-3.txt
+  5  30 151 total
diff --git a/expect/jq/script-01.sh b/expect/jq/script-01.sh
new file mode 100755
index 0000000..e16f4ed
--- /dev/null
+++ b/expect/jq/script-01.sh
@@ -0,0 +1 @@
+Selma
diff --git a/expect/jq/script-02.sh b/expect/jq/script-02.sh
new file mode 100755
index 0000000..18711af
--- /dev/null
+++ b/expect/jq/script-02.sh
@@ -0,0 +1 @@
+35 Fashion Street, London, E1 6PX
diff --git a/expect/jq/script-03.sh b/expect/jq/script-03.sh
new file mode 100755
index 0000000..d63f6ec
--- /dev/null
+++ b/expect/jq/script-03.sh
@@ -0,0 +1,2 @@
+Selma, Software Engineer
+Selma, Software Engineer
diff --git a/expect/jq/script-04.sh b/expect/jq/script-04.sh
new file mode 100755
index 0000000..050f043
--- /dev/null
+++ b/expect/jq/script-04.sh
@@ -0,0 +1,6 @@
+Ahmed
+Basia
+Mehmet
+Leila
+Piotr
+Chandra
diff --git a/expect/jq/script-05.sh b/expect/jq/script-05.sh
new file mode 100755
index 0000000..ee7e0fe
--- /dev/null
+++ b/expect/jq/script-05.sh
@@ -0,0 +1,6 @@
+Ahmed London
+Basia London
+Mehmet Birmingham
+Leila London
+Piotr Glasgow
+Chandra Birmingham
diff --git a/expect/jq/script-06.sh b/expect/jq/script-06.sh
new file mode 100755
index 0000000..f5d0b1f
--- /dev/null
+++ b/expect/jq/script-06.sh
@@ -0,0 +1,6 @@
+Ahmed 1
+Basia 22
+Mehmet 3
+Leila 1
+Piotr 15
+Chandra 12
diff --git a/expect/jq/script-07.sh b/expect/jq/script-07.sh
new file mode 100755
index 0000000..59c783f
--- /dev/null
+++ b/expect/jq/script-07.sh
@@ -0,0 +1,6 @@
+Ahmed 4
+Basia 6
+Mehmet 17
+Leila 1
+Piotr 8
+Chandra 6
diff --git a/expect/jq/script-08.sh b/expect/jq/script-08.sh
new file mode 100755
index 0000000..dd7e1d3
--- /dev/null
+++ b/expect/jq/script-08.sh
@@ -0,0 +1,6 @@
+Ahmed 3
+Basia 3
+Mehmet 3
+Leila 1
+Piotr 5
+Chandra 2
diff --git a/expect/jq/script-09.sh b/expect/jq/script-09.sh
new file mode 100755
index 0000000..33ff777
--- /dev/null
+++ b/expect/jq/script-09.sh
@@ -0,0 +1,6 @@
+Ahmed 15
+Basia 37
+Mehmet 32
+Leila 1
+Piotr 61
+Chandra 18
diff --git a/expect/jq/script-10.sh b/expect/jq/script-10.sh
new file mode 100755
index 0000000..fb1e7bc
--- /dev/null
+++ b/expect/jq/script-10.sh
@@ -0,0 +1 @@
+54
diff --git a/expect/jq/script-11.sh b/expect/jq/script-11.sh
new file mode 100755
index 0000000..4e9bdff
--- /dev/null
+++ b/expect/jq/script-11.sh
@@ -0,0 +1 @@
+164
diff --git a/expect/number-systems/Part-1.json b/expect/number-systems/Part-1.json
new file mode 100644
index 0000000..d96c538
--- /dev/null
+++ b/expect/number-systems/Part-1.json
@@ -0,0 +1 @@
+{"answers": [0, 1110, 45, 1000, "01011", 11111, 100010, 15, 8, 2, "(10$|10[^0-9])", "E", 182, 902, 11, 33]}
diff --git a/expect/shell-pipelines/ls-grep/script-01.sh b/expect/shell-pipelines/ls-grep/script-01.sh
new file mode 100755
index 0000000..5481774
--- /dev/null
+++ b/expect/shell-pipelines/ls-grep/script-01.sh
@@ -0,0 +1,11 @@
+Ariane
+Daniel
+HoChiMinh
+KualaLumpur
+Levi
+London
+NewYork
+Niamh
+Olga
+York
+dHondt
diff --git a/expect/shell-pipelines/ls-grep/script-02.sh b/expect/shell-pipelines/ls-grep/script-02.sh
new file mode 100755
index 0000000..35f2e44
--- /dev/null
+++ b/expect/shell-pipelines/ls-grep/script-02.sh
@@ -0,0 +1,10 @@
+Ariane
+Daniel
+HoChiMinh
+KualaLumpur
+Levi
+London
+NewYork
+Niamh
+Olga
+York
diff --git a/expect/shell-pipelines/ls-grep/script-03.sh b/expect/shell-pipelines/ls-grep/script-03.sh
new file mode 100755
index 0000000..37ec450
--- /dev/null
+++ b/expect/shell-pipelines/ls-grep/script-03.sh
@@ -0,0 +1,7 @@
+Ariane
+Daniel
+Levi
+London
+Niamh
+Olga
+York
diff --git a/expect/shell-pipelines/ls-grep/script-04.sh b/expect/shell-pipelines/ls-grep/script-04.sh
new file mode 100755
index 0000000..7f8f011
--- /dev/null
+++ b/expect/shell-pipelines/ls-grep/script-04.sh
@@ -0,0 +1 @@
+7
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-01.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-01.sh
new file mode 100755
index 0000000..a622bc9
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-01.sh
@@ -0,0 +1,6 @@
+Ahmed London 1 10 4
+Basia London 22 9 6
+Chandra Birmingham 12 6
+Leila London 1
+Mehmet Birmingham 3 12 17
+Piotr Glasgow 15 2 25 11 8
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-02.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-02.sh
new file mode 100755
index 0000000..c560f60
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-02.sh
@@ -0,0 +1,6 @@
+Basia London 22 9 6
+Piotr Glasgow 15 2 25 11 8
+Chandra Birmingham 12 6
+Mehmet Birmingham 3 12 17
+Leila London 1
+Ahmed London 1 10 4
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-03.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-03.sh
new file mode 100755
index 0000000..52d05bc
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-03.sh
@@ -0,0 +1,3 @@
+Basia London 22 9 6
+Piotr Glasgow 15 2 25 11 8
+Chandra Birmingham 12 6
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-04.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-04.sh
new file mode 100755
index 0000000..9c18f93
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-04.sh
@@ -0,0 +1 @@
+Piotr Glasgow 15 2 25 11 8
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-05.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-05.sh
new file mode 100755
index 0000000..5b6440e
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-05.sh
@@ -0,0 +1,6 @@
+Entry German
+Entry Mariana
+Entry Sally
+Exit German
+Exit Mariana
+Exit Sally
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-06.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-06.sh
new file mode 100755
index 0000000..93bd06b
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-06.sh
@@ -0,0 +1,2 @@
+      5 Entry
+      4 Exit
diff --git a/expect/shell-pipelines/sort-uniq-head-tail/script-07.sh b/expect/shell-pipelines/sort-uniq-head-tail/script-07.sh
new file mode 100755
index 0000000..93bd06b
--- /dev/null
+++ b/expect/shell-pipelines/sort-uniq-head-tail/script-07.sh
@@ -0,0 +1,2 @@
+      5 Entry
+      4 Exit
diff --git a/expect/shell-pipelines/tr/script-01.sh b/expect/shell-pipelines/tr/script-01.sh
new file mode 100755
index 0000000..8dea4eb
--- /dev/null
+++ b/expect/shell-pipelines/tr/script-01.sh
@@ -0,0 +1,11 @@
+Dear Yara,
+
+Mz apologies for sending this response so late. As zou know, there's been a lot going on.
+
+Unfortunatelz I don't think I'll be able to make it to Yimbabwe, but but sounds amaying.
+
+Hope zou're doing well, and enjoz the trip.
+
+Thanks,
+
+Karolina
diff --git a/expect/shell-pipelines/tr/script-02.sh b/expect/shell-pipelines/tr/script-02.sh
new file mode 100755
index 0000000..e00561a
--- /dev/null
+++ b/expect/shell-pipelines/tr/script-02.sh
@@ -0,0 +1,11 @@
+Dear Zara,
+
+My apologies for sending this response so late. As you know, there's been a lot going on!
+
+Unfortunately I don't think I'll be able to make it to Zimbabwe, but but sounds amazing!
+
+Hope you're doing well, and enjoy the trip!
+
+Thanks,
+
+Karolina
diff --git a/number-systems/Part-1.md b/number-systems/Part-1.md
new file mode 100644
index 0000000..d8f9c29
--- /dev/null
+++ b/number-systems/Part-1.md
@@ -0,0 +1,54 @@
+Do not use any tools or programming to solve these problems. Work it out yourself by hand, and fill in the answers.
+
+Do not convert any binary numbers to decimal when solving a question unless the question explicitly tells you to.
+
+The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point.
+
+The answers to these questions should be a number, either in binary, hex, or decimal.
+
+Q1: Convert the decimal number 14 to binary.
+Answer:
+
+Q2: Convert the binary number 101101 to decimal:
+Answer:
+
+Q3: Which is larger: 1000 or 0111?
+Answer:
+
+Q4: Which is larger: 00100 or 01011?
+Answer:
+
+Q5: What is 10101 + 01010?
+Answer:
+
+Q6: What is 10001 + 10001?
+Answer:
+
+Q7: What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
+Answer:
+
+Q8: How many bits would you need in order to store the numbers between 0 and 255 inclusive?
+Answer:
+
+Q9: How many bits would you need in order to store the numbers between 0 and 3 inclusive?
+Answer:
+
+Q10: How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
+Answer:
+
+Q11: Convert the decimal number 14 to hex.
+Answer:
+ 
+Q12: Convert the decimal number 386 to hex.
+Answer:
+
+Q13: Convert the hex number 386 to decimal.
+Answer:
+
+Q14: Convert the hex number B to decimal.
+Answer:
+
+Q15: If reading the byte 0x21 as a number, what decimal number would it mean?
+Answer:
+
+Q16: Continues in Part-2
diff --git a/number-systems/Part-2.md b/number-systems/Part-2.md
new file mode 100644
index 0000000..92b7005
--- /dev/null
+++ b/number-systems/Part-2.md
@@ -0,0 +1,22 @@
+Do not use any tools or programming to solve these problems. Work it out yourself by hand, and fill in the answers.
+
+Do not convert any binary numbers to decimal when solving a question unless the question explicitly tells you to.
+
+The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point.
+
+The answers to these questions will require a bit of explanation, not just a simple answer.
+
+Q16: How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
+Answer: 
+
+Q17: If reading the byte 0x21 as an ASCII character, what character would it mean?
+Answer: 
+
+Q18: If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
+Answer: 
+
+Q19: If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
+Answer: 
+
+Q20: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
+Answer: 
diff --git a/number-systems/README.md b/number-systems/README.md
deleted file mode 100644
index 77a3bde..0000000
--- a/number-systems/README.md
+++ /dev/null
@@ -1,65 +0,0 @@
-Do not use any tools or programming to solve these problems. Work it out yourself by hand, and fill in the answers.
-
-Do not convert any binary numbers to decimal when solving a question unless the question explicitly tells you to.
-
-The goal of these exercises is for you to gain an intuition for binary numbers. Using tools to solve the problems defeats the point.
-
-Convert the decimal number 14 to binary.
-Answer:
-
-Convert the binary number 101101 to decimal:
-Answer:
-
-Which is larger: 1000 or 0111?
-Answer:
-
-Which is larger: 00100 or 01011?
-Answer:
-
-What is 10101 + 01010?
-Answer:
-
-What is 10001 + 10001?
-Answer:
-
-What's the largest number you can store with 4 bits, if you want to be able to represent the number 0?
-Answer:
-
-How many bits would you need in order to store the numbers between 0 and 255 inclusive?
-Answer:
-
-How many bits would you need in order to store the numbers between 0 and 3 inclusive?
-Answer:
-
-How many bits would you need in order to store the numbers between 0 and 1000 inclusive?
-Answer:
-
-How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
-Answer:
-
-Convert the decimal number 14 to hex.
-Answer:
-
-Convert the decimal number 386 to hex.
-Answer:
-
-Convert the hex number 386 to decimal.
-Answer:
-
-Convert the hex number B to decimal.
-Answer:
-
-If reading the byte 0x21 as a number, what decimal number would it mean?
-Answer:
-
-If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer:
-
-If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
-
-If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer:
-
-If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer:
diff --git a/test-sdc.sh b/test-sdc.sh
new file mode 100755
index 0000000..b8f32cf
--- /dev/null
+++ b/test-sdc.sh
@@ -0,0 +1,132 @@
+# This test file will be automatically run when you submit a pull request
+# You should not modify this file
+# You can run this file using ./test-sdc.sh task-directory-name to check your output
+
+echo "<!--CYFTT tag: sdc-test-results-->" > testoutput.txt
+echo "Results of test" >> testoutput.txt
+
+if [[ "$1" == "individual-shell-tools" ]]; then
+	cd individual-shell-tools
+	pass=0
+	total=0
+	for directory in */; do
+		cd $directory
+		if [ "$directory" == "helper-files/" ]; then
+			cd ..
+			continue
+		fi
+		for exercise in *.sh; do
+			total=$(($total+1))
+			./$exercise > ../../test.tmp
+			cmp ../../test.tmp ../../expect/individual-shell-tools/$directory$exercise --quiet
+			if [ $? -eq 0 ]; then
+				pass=$(($pass+1))
+			else
+				if [[ "$exercise" == *"stretch"* && $(stat -c%s ../../test.tmp) == "0" ]]; then
+					# Stretch task not attempted, ignoring"
+					total=$(($total-1))
+				else
+					echo "Failed $directory$exercise, please check" >> ../../testoutput.txt
+				fi
+			fi
+		done
+		cd ..
+	done
+	cd ..
+	rm test.tmp
+	echo "You passed $pass/$total tasks." >> testoutput.txt
+	if [ -v GITHUB_OUTPUT ]; then
+		echo "attempted=y" >> "$GITHUB_OUTPUT"
+	fi
+	if [ $pass -ge $total ]; then
+		echo "This task is complete!" >> testoutput.txt
+		if [ -v GITHUB_OUTPUT ]; then
+			echo "complete=y" >> "$GITHUB_OUTPUT"
+		fi
+	fi
+	cat testoutput.txt
+elif [[ "$1" == "shell-pipelines" ]]; then
+	cd shell-pipelines
+	pass=0
+	total=0
+	for directory in */; do
+		cd $directory
+		for exercise in *.sh; do
+			total=$(($total+1))
+			./$exercise > ../../test.tmp
+			cmp ../../test.tmp ../../expect/shell-pipelines/$directory$exercise --quiet
+			if [ $? -eq 0 ]; then
+				pass=$(($pass+1))
+			else
+				echo "Failed $directory$exercise, please check" >> ../../testoutput.txt
+			fi
+		done
+		cd ..
+	done
+	cd ..
+	rm test.tmp
+	echo "You passed $pass/$total tasks." >> testoutput.txt
+	if [ -v GITHUB_OUTPUT ]; then
+		echo "attempted=y" >> "$GITHUB_OUTPUT"
+	fi
+	if [ $pass -eq $total ]; then
+		echo "This task is complete!" >> testoutput.txt
+		if [ -v GITHUB_OUTPUT ]; then
+			echo "complete=y" >> "$GITHUB_OUTPUT"
+		fi
+	fi
+	cat testoutput.txt
+elif [[ "$1" == "jq" ]]; then
+	cd jq
+	pass=0
+	total=0
+	for exercise in *.sh; do
+		total=$(($total+1))
+		./$exercise > ../test.tmp
+		cmp ../test.tmp ../expect/jq/$exercise --quiet
+		if [ $? -eq 0 ]; then
+			pass=$(($pass+1))
+		else
+			echo "Failed $exercise, please check" >> ../testoutput.txt
+		fi
+	done
+	cd ..
+	rm test.tmp
+	echo "You passed $pass/$total tasks." >> testoutput.txt
+	if [ -v GITHUB_OUTPUT ]; then
+		echo "attempted=y" >> "$GITHUB_OUTPUT"
+	fi
+	if [ $pass -eq $total ]; then
+		echo "This task is complete!" >> testoutput.txt
+		if [ -v GITHUB_OUTPUT ]; then
+			echo "complete=y" >> "$GITHUB_OUTPUT"
+		fi
+	fi
+	cat testoutput.txt
+elif [[ "$1" == "number-systems" ]]; then
+	pass=0
+	for question in $(seq 1 15); do
+		answer=$(jq -r ".answers[$question]" expect/number-systems/Part-1.json)
+		nextq=$(($question+1))
+		Q_START=$(grep -n "Q$question:" number-systems/Part-1.md | cut -d: -f1)
+		ANS_START=$(($Q_START + 1))
+		NEXT_Q_START=$(grep -n "Q$nextq:" number-systems/Part-1.md | cut -d: -f1)
+		ANS_END=$(($NEXT_Q_START - 1))
+		sed -n "$ANS_START,${ANS_END}p;${NEXT_Q_START}q" number-systems/Part-1.md | cut -d: -f2- > answerfile
+		grep --quiet -iE $answer answerfile
+		if [ $? -eq 0 ]; then
+			pass=$(($pass+1))
+		else
+			echo "Q$question incorrect, please check" >> testoutput.txt
+		fi
+		rm answerfile
+	done
+	echo "You passed $pass/15 tasks in part 1." >> testoutput.txt
+	if [ -v GITHUB_OUTPUT ]; then
+		echo "attempted=y" >> "$GITHUB_OUTPUT"
+	fi
+	echo "Please let a volunteer check the answers for part 2." >> testoutput.txt
+	cat testoutput.txt
+else
+	echo "Please run this with a valid test directory name as argument"
+fi

From f38fee54def1961f51947ca50ef9dde930a00c39 Mon Sep 17 00:00:00 2001
From: Daniel Wagner-Hall <daniel@codeyourfuture.io>
Date: Tue, 12 May 2026 14:26:50 +0100
Subject: [PATCH 03/24] Make test-sdc script more portable (#520)

* Add a shebang because `-v` is a bash-ism not present in whatever my
default shell is on macOS.
* Remove `--quiet` from `cmp` - macOS's `cmp` doesn't support it.
---
 test-sdc.sh | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/test-sdc.sh b/test-sdc.sh
index b8f32cf..acf9897 100755
--- a/test-sdc.sh
+++ b/test-sdc.sh
@@ -1,3 +1,5 @@
+#!/bin/bash
+
 # This test file will be automatically run when you submit a pull request
 # You should not modify this file
 # You can run this file using ./test-sdc.sh task-directory-name to check your output
@@ -18,7 +20,7 @@ if [[ "$1" == "individual-shell-tools" ]]; then
 		for exercise in *.sh; do
 			total=$(($total+1))
 			./$exercise > ../../test.tmp
-			cmp ../../test.tmp ../../expect/individual-shell-tools/$directory$exercise --quiet
+			cmp ../../test.tmp ../../expect/individual-shell-tools/$directory$exercise
 			if [ $? -eq 0 ]; then
 				pass=$(($pass+1))
 			else
@@ -54,7 +56,7 @@ elif [[ "$1" == "shell-pipelines" ]]; then
 		for exercise in *.sh; do
 			total=$(($total+1))
 			./$exercise > ../../test.tmp
-			cmp ../../test.tmp ../../expect/shell-pipelines/$directory$exercise --quiet
+			cmp ../../test.tmp ../../expect/shell-pipelines/$directory$exercise
 			if [ $? -eq 0 ]; then
 				pass=$(($pass+1))
 			else
@@ -83,7 +85,7 @@ elif [[ "$1" == "jq" ]]; then
 	for exercise in *.sh; do
 		total=$(($total+1))
 		./$exercise > ../test.tmp
-		cmp ../test.tmp ../expect/jq/$exercise --quiet
+		cmp ../test.tmp ../expect/jq/$exercise
 		if [ $? -eq 0 ]; then
 			pass=$(($pass+1))
 		else

From ab33fa5254177acf1df97d1557f5f87ef9a5eeeb Mon Sep 17 00:00:00 2001
From: Daniel Wagner-Hall <daniel@codeyourfuture.io>
Date: Tue, 12 May 2026 15:26:14 +0100
Subject: [PATCH 04/24] Add automated tests for cowsay implementation (#521)

---
 .github/workflows/validate-pr-metadata.yml | 11 +++--
 expect/implement-cowsay/cow-grass.txt      | 10 +++++
 expect/implement-cowsay/turtle-fish.txt    | 22 ++++++++++
 test-sdc.sh                                | 47 ++++++++++++++++++++++
 4 files changed, 87 insertions(+), 3 deletions(-)
 create mode 100644 expect/implement-cowsay/cow-grass.txt
 create mode 100644 expect/implement-cowsay/turtle-fish.txt

diff --git a/.github/workflows/validate-pr-metadata.yml b/.github/workflows/validate-pr-metadata.yml
index 8ff276f..b4ff602 100644
--- a/.github/workflows/validate-pr-metadata.yml
+++ b/.github/workflows/validate-pr-metadata.yml
@@ -48,15 +48,20 @@ jobs:
         if: contains(steps.changed-files.outputs.modified_files, 'number-systems/')
         run: ./test-sdc.sh number-systems
         shell: bash
+      - name: test implement-cowsay
+        id: test-implement-cowsay
+        if: contains(steps.changed-files.outputs.modified_files, 'implement-cowsay/')
+        run: ./test-sdc.sh implement-cowsay
+        shell: bash
       - name: make output comment
-        if: steps.test-individual-shell-tools.outputs.attempted == 'y' || steps.test-jq.outputs.attempted == 'y' || steps.test-shell-pipelines.outputs.attempted == 'y' || steps.test-number-systems.outputs.attempted == 'y'
+        if: steps.test-individual-shell-tools.outputs.attempted == 'y' || steps.test-jq.outputs.attempted == 'y' || steps.test-shell-pipelines.outputs.attempted == 'y' || steps.test-number-systems.outputs.attempted == 'y' || steps.test-implement-cowsay.outputs.attempted == 'y'
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           ISSUE_URL: ${{ github.event.pull_request.html_url }}
         run: |
           gh pr comment $ISSUE_URL --body-file testoutput.txt
       - name: add appropriate labels
-        if: steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y'
+        if: steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y' || steps.test-implement-cowsay.outputs.complete == 'y'
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           ISSUE_URL: ${{ github.event.pull_request.html_url }}
@@ -64,6 +69,6 @@ jobs:
           gh pr edit $ISSUE_URL --add-label "Complete"
           gh pr edit $ISSUE_URL --remove-label "Needs Review"
       - name: fail if not complete
-        if: (steps.test-individual-shell-tools.outputs.attempted == 'y' || steps.test-jq.outputs.attempted == 'y' || steps.test-shell-pipelines.outputs.attempted == 'y') && !(steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y')
+        if: (steps.test-individual-shell-tools.outputs.attempted == 'y' || steps.test-jq.outputs.attempted == 'y' || steps.test-shell-pipelines.outputs.attempted == 'y' || steps.test-implement-cowsay.outputs.attempted == 'y') && !(steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y' || steps.test-implement-cowsay.outputs.complete == 'y')
         run: |
           exit -1
diff --git a/expect/implement-cowsay/cow-grass.txt b/expect/implement-cowsay/cow-grass.txt
new file mode 100644
index 0000000..d9c665a
--- /dev/null
+++ b/expect/implement-cowsay/cow-grass.txt
@@ -0,0 +1,10 @@
+  ________________
+| Grass, delicious |
+  ================
+                \
+                 \
+                   ^__^
+                   (oo)\_______
+                   (__)\       )\/\
+                       ||----w |
+                       ||     ||
diff --git a/expect/implement-cowsay/turtle-fish.txt b/expect/implement-cowsay/turtle-fish.txt
new file mode 100644
index 0000000..5dadfa0
--- /dev/null
+++ b/expect/implement-cowsay/turtle-fish.txt
@@ -0,0 +1,22 @@
+  ______________
+| Fish are cool! |
+  ==============
+                \
+                 \
+                  \
+                   \
+                                              ___-------___
+                                          _-~~             ~~-_
+                                       _-~                    /~-_
+                     /^\__/^\         /~  \                   /    \
+                   /|  O|| O|        /      \_______________/        \
+                  | |___||__|      /       /                \          \
+                  |          \    /      /                    \          \
+                  |   (_______) /______/                        \_________ \
+                  |         / /         \                      /            \
+                   \         \^\\         \                  /               \     /
+                     \         ||           \______________/      _-_       //\__//
+                       \       ||------_-~~-_ ------------- \ --/~   ~\    || __/
+                         ~-----||====/~     |==================|       |/~~~~~
+                          (_(__/  ./     /                    \_\      \.
+                                 (_(___/                         \_____)_)
diff --git a/test-sdc.sh b/test-sdc.sh
index acf9897..adc8dc4 100755
--- a/test-sdc.sh
+++ b/test-sdc.sh
@@ -129,6 +129,53 @@ elif [[ "$1" == "number-systems" ]]; then
 	fi
 	echo "Please let a volunteer check the answers for part 2." >> testoutput.txt
 	cat testoutput.txt
+elif [[ "$1" == "implement-cowsay" ]]; then
+  if [ -v GITHUB_OUTPUT ]; then
+    echo "attempted=y" >> "$GITHUB_OUTPUT"
+  fi
+  if [[ -e .cowsay-venv ]]; then
+    echo ".cowsay-venv already exists - couldn't test cowsay" >> testoutput.txt
+  else
+    if [ ! -e implement-cowsay/requirements.txt ]; then
+      echo "Expected implement-cowsay/requirements.txt to exist but it didn't" >> testoutput.txt
+    else
+      python3 -m venv .cowsay-venv
+      . .cowsay-venv/bin/activate
+      pip3 install -r implement-cowsay/requirements.txt
+
+      all_ok=true
+
+      python3 implement-cowsay/cow.py Grass, delicious > test.tmp
+      cmp test.tmp expect/implement-cowsay/cow-grass.txt
+      if [ $? -ne 0 ]; then
+        echo "Unexpected cowsay output for Grass, delicious" >> testoutput.txt
+        all_ok=false
+      fi
+
+      python3 implement-cowsay/cow.py --animal turtle "Fish are cool!" > test.tmp
+      cmp test.tmp expect/implement-cowsay/turtle-fish.txt
+      if [ $? -ne 0 ]; then
+        echo "Unexpected cowsay output for Fish are cool!" >> testoutput.txt
+        all_ok=false
+      fi
+
+      python3 implement-cowsay/cow.py --help | grep dragon
+      if [ $? -ne 0 ]; then
+        echo "Expected python3 cow.py --help to include dragon as it's one of the animal options" >> testoutput.txt
+        all_ok=false
+      fi
+
+      grep dragon implement-cowsay/cow.py > /dev/null
+      if [ $? -eq 0 ]; then
+        echo "Didn't expect cow.py to include the word dragon - you should pull in the animal options from the library not write them yourself" >> testoutput.txt
+        all_ok=false
+      fi
+
+      if [[ "${all_ok}" == "true" && -v GITHUB_OUTPUT ]]; then
+        echo "completed=y" >> "$GITHUB_OUTPUT"
+      fi
+    fi
+  fi
 else
 	echo "Please run this with a valid test directory name as argument"
 fi

From d3857c25cc7a1a94111183aa2901ef73c45c4865 Mon Sep 17 00:00:00 2001
From: Daniel Wagner-Hall <daniel@codeyourfuture.io>
Date: Wed, 13 May 2026 10:05:37 +0100
Subject: [PATCH 05/24] Improve cowsay comments (#522)

* Trigger on added files - Cowsay involves writing brand new files
* Hide previous comments
* Fix completed -> complete
* Clean up output a little
---
 .github/workflows/validate-pr-metadata.yml | 4 +++-
 test-sdc.sh                                | 9 +++++----
 2 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/validate-pr-metadata.yml b/.github/workflows/validate-pr-metadata.yml
index b4ff602..6fa2e1d 100644
--- a/.github/workflows/validate-pr-metadata.yml
+++ b/.github/workflows/validate-pr-metadata.yml
@@ -50,7 +50,7 @@ jobs:
         shell: bash
       - name: test implement-cowsay
         id: test-implement-cowsay
-        if: contains(steps.changed-files.outputs.modified_files, 'implement-cowsay/')
+        if: contains(steps.changed-files.outputs.all_modified_files, 'implement-cowsay/')
         run: ./test-sdc.sh implement-cowsay
         shell: bash
       - name: make output comment
@@ -59,6 +59,8 @@ jobs:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           ISSUE_URL: ${{ github.event.pull_request.html_url }}
         run: |
+          gh release -R CodeYourFuture/trainee-tracker view --json assets -q ".assets[] | select(.name | startswith(\"pr-metadata-validator-musl-\")).url" | xargs curl --fail -L -o /tmp/pr-metadata-validator && chmod 0755 /tmp/pr-metadata-validator
+          /tmp/pr-metadata-validator --only-close-existing-comments-with-tag="sdc-test-results" "${ISSUE_URL}"
           gh pr comment $ISSUE_URL --body-file testoutput.txt
       - name: add appropriate labels
         if: steps.test-individual-shell-tools.outputs.complete == 'y' || steps.test-jq.outputs.complete == 'y' || steps.test-shell-pipelines.outputs.complete == 'y' || steps.test-implement-cowsay.outputs.complete == 'y'
diff --git a/test-sdc.sh b/test-sdc.sh
index adc8dc4..62d1c7e 100755
--- a/test-sdc.sh
+++ b/test-sdc.sh
@@ -5,7 +5,7 @@
 # You can run this file using ./test-sdc.sh task-directory-name to check your output
 
 echo "<!--CYFTT tag: sdc-test-results-->" > testoutput.txt
-echo "Results of test" >> testoutput.txt
+echo "Results of test:" >> testoutput.txt
 
 if [[ "$1" == "individual-shell-tools" ]]; then
 	cd individual-shell-tools
@@ -148,14 +148,14 @@ elif [[ "$1" == "implement-cowsay" ]]; then
       python3 implement-cowsay/cow.py Grass, delicious > test.tmp
       cmp test.tmp expect/implement-cowsay/cow-grass.txt
       if [ $? -ne 0 ]; then
-        echo "Unexpected cowsay output for Grass, delicious" >> testoutput.txt
+        echo "Unexpected cowsay output for 'Grass, delicious'." >> testoutput.txt
         all_ok=false
       fi
 
       python3 implement-cowsay/cow.py --animal turtle "Fish are cool!" > test.tmp
       cmp test.tmp expect/implement-cowsay/turtle-fish.txt
       if [ $? -ne 0 ]; then
-        echo "Unexpected cowsay output for Fish are cool!" >> testoutput.txt
+        echo "Unexpected cowsay output for --animal turtle Fish are cool!" >> testoutput.txt
         all_ok=false
       fi
 
@@ -172,7 +172,8 @@ elif [[ "$1" == "implement-cowsay" ]]; then
       fi
 
       if [[ "${all_ok}" == "true" && -v GITHUB_OUTPUT ]]; then
-        echo "completed=y" >> "$GITHUB_OUTPUT"
+        echo "complete=y" >> "$GITHUB_OUTPUT"
+        echo "Your implementation passed all checks." >> testoutput.txt
       fi
     fi
   fi

From 47e4131a87e815f7a089e6393b43b7ef9354f413 Mon Sep 17 00:00:00 2001
From: Poonam <61753159+Poonam-raj@users.noreply.github.com>
Date: Wed, 10 Jun 2026 11:07:31 +0100
Subject: [PATCH 06/24] switching last two hex questions (#533)

So a trainee has to convert the hex into a number before considering how
this might look as colours.

Ideally to improve lead into the idea of that % of bytes used can create
the colour mix.

Same could be said for the grey question needing more suggestion of how
to calculate a colour mix (somehow hinting or leading to the idea of
proportion of bytes used).

Suggestions welcome for whether this fixes a misunderstanding or not, or
if it can be improved.
---
 number-systems/Part-2.md | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/number-systems/Part-2.md b/number-systems/Part-2.md
index 92b7005..68b0933 100644
--- a/number-systems/Part-2.md
+++ b/number-systems/Part-2.md
@@ -7,16 +7,16 @@ The goal of these exercises is for you to gain an intuition for binary numbers.
 The answers to these questions will require a bit of explanation, not just a simple answer.
 
 Q16: How can you test if a binary number is a power of two (e.g. 1, 2, 4, 8, 16, ...)?
-Answer: 
+Answer:
 
 Q17: If reading the byte 0x21 as an ASCII character, what character would it mean?
-Answer: 
+Answer:
 
 Q18: If reading the byte 0x21 as a greyscale colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer: 
+Answer:
 
-Q19: If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
-Answer: 
+Q19: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
+Answer:
 
-Q20: If reading the bytes 0xAA00FF as a sequence of three one-byte decimal numbers, what decimal numbers would they be?
-Answer: 
+Q20: If reading the bytes 0xAA00FF as an RGB colour, as described in "Approaches for Representing Colors and Images", what colour would it mean?
+Answer:

From 3f26722eca564c25fc8ac11e99327544b55445a3 Mon Sep 17 00:00:00 2001
From: Daniel Wagner-Hall <daniel@codeyourfuture.io>
Date: Wed, 24 Jun 2026 15:34:38 +0100
Subject: [PATCH 07/24] Add more expected test cases for ls implementations
 (#441)

Some trainees are doing a bit less than I was expecting when originally
setting this.

Not to be merged util the current cohort have completed Module-Tools.
---
 implement-shell-tools/ls/README.md | 3 +++
 implement-shell-tools/wc/README.md | 2 ++
 2 files changed, 5 insertions(+)

diff --git a/implement-shell-tools/ls/README.md b/implement-shell-tools/ls/README.md
index edbfb81..c0b81e0 100644
--- a/implement-shell-tools/ls/README.md
+++ b/implement-shell-tools/ls/README.md
@@ -6,6 +6,9 @@ Your task is to implement your own version of `ls`.
 
 It must act the same as `ls` would, if run from the directory containing this README.md file, for the following command lines:
 
+* `ls sample-files`
+* `ls sample-files/1.txt`
+* `ls sample-files/*`
 * `ls -1`
 * `ls -1 sample-files`
 * `ls -1 -a sample-files`
diff --git a/implement-shell-tools/wc/README.md b/implement-shell-tools/wc/README.md
index bd76b65..925e522 100644
--- a/implement-shell-tools/wc/README.md
+++ b/implement-shell-tools/wc/README.md
@@ -11,6 +11,8 @@ It must act the same as `wc` would, if run from the directory containing this RE
 * `wc -w sample-files/3.txt`
 * `wc -c sample-files/3.txt`
 * `wc -l sample-files/*`
+* `wc -w -l sample-files/3.txt`
+* `wc -w -l sample-files/*`
 
 Matching any additional behaviours or flags are optional stretch goals.
 

From 78bdfd5f5130b16853693f87d5b920acfa710cda Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Tue, 28 Jul 2026 10:08:03 +0100
Subject: [PATCH 08/24] cat implemented

---
 implement-shell-tools/cat/cat.js | 46 ++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)
 create mode 100644 implement-shell-tools/cat/cat.js

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
new file mode 100644
index 0000000..e21ac51
--- /dev/null
+++ b/implement-shell-tools/cat/cat.js
@@ -0,0 +1,46 @@
+const fs = require("fs");
+
+const arguments = process.argv;
+const filePaths = arguments.slice(2);
+
+const index = arguments[1].lastIndexOf("/");
+const currentWorkingDirectory = arguments[1].slice(0, index + 1);
+
+let flag = filePaths[0];
+if (flag.charAt(0) == "-") {
+  flag = filePaths.shift();
+}
+
+function splitFile(fileName) {
+  const filePath = currentWorkingDirectory + fileName;
+  const text = fs.readFileSync(filePath, "utf8").trimEnd();
+  return text.split("\n");
+}
+
+function printFile(lines) {
+  lines.forEach((line) => {
+    console.log(line);
+  });
+}
+
+function executeFlag(lines) {
+  if (flag === "-n") {
+    return lines.map((line, index) => `${String(index + 1).padStart(6, " ")} ${line}`);
+  } else if (flag === "-b") {
+    let lineNumber = 1;
+    return lines.map((line) => {
+      if (line === "") {
+        return `${line}`;
+      }
+      return `${String(lineNumber++).padStart(6, " ")} ${line}`;
+    });
+  } else {
+    return lines;
+  }
+}
+
+filePaths.forEach((filePath) => {
+  let lines = splitFile(filePath);
+  lines = executeFlag(lines);
+  printFile(lines);
+});

From 60b323e23467c6d21b1abe736ddcb10bd41f8c4e Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Tue, 28 Jul 2026 20:10:51 +0100
Subject: [PATCH 09/24] cat updated

---
 implement-shell-tools/cat/cat.js | 77 +++++++++++++++++++++-----------
 1 file changed, 52 insertions(+), 25 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index e21ac51..e9dcd91 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -1,46 +1,73 @@
 const fs = require("fs");
 
 const arguments = process.argv;
-const filePaths = arguments.slice(2);
+const userArguments = arguments.slice(2);
 
 const index = arguments[1].lastIndexOf("/");
 const currentWorkingDirectory = arguments[1].slice(0, index + 1);
 
-let flag = filePaths[0];
-if (flag.charAt(0) == "-") {
-  flag = filePaths.shift();
+const flags = userArguments
+  .filter((argument) => argument.startsWith("-"))
+  .map((argument) => argument.slice(1))
+  .join("");
+
+const flagHandlers = {
+  b: bFlag,
+  n: nFlag,
+};
+
+const fileNames = userArguments.filter((argument) => !argument.startsWith("-"));
+let allFilesContents = [];
+
+readFiles();
+executeFlags();
+printLines();
+
+function readFiles() {
+  fileNames.forEach((fileName) => {
+    fileContent = readFile(fileName);
+    allFilesContents.push(fileContent.split("\n"));
+  });
 }
 
-function splitFile(fileName) {
+function readFile(fileName) {
   const filePath = currentWorkingDirectory + fileName;
-  const text = fs.readFileSync(filePath, "utf8").trimEnd();
-  return text.split("\n");
+  return fs.readFileSync(filePath, "utf8").trimEnd();
 }
 
-function printFile(lines) {
-  lines.forEach((line) => {
-    console.log(line);
-  });
+function executeFlags() {
+  for (const flag of flags) {
+    if (flagHandlers[flag]) {
+      allFilesContents = flagHandlers[flag]();
+    } else {
+      console.error(`cat: illegal option -- ${flag}\nusage: cat [-belnstuv] [file ...]`);
+      process.exit(1);
+    }
+  }
 }
 
-function executeFlag(lines) {
-  if (flag === "-n") {
-    return lines.map((line, index) => `${String(index + 1).padStart(6, " ")} ${line}`);
-  } else if (flag === "-b") {
+function bFlag() {
+  return allFilesContents.map((fileContent) => {
     let lineNumber = 1;
-    return lines.map((line) => {
-      if (line === "") {
+    return fileContent.map((line, index) => {
+      if (line == "") {
         return `${line}`;
       }
       return `${String(lineNumber++).padStart(6, " ")} ${line}`;
     });
-  } else {
-    return lines;
-  }
+  });
+}
+
+function nFlag() {
+  return allFilesContents.map((fileContent) => {
+    return fileContent.map((line, index) => `${String(index + 1).padStart(6, " ")} ${line}`);
+  });
 }
 
-filePaths.forEach((filePath) => {
-  let lines = splitFile(filePath);
-  lines = executeFlag(lines);
-  printFile(lines);
-});
+function printLines() {
+  allFilesContents.forEach((fileContent) => {
+    fileContent.forEach((line) => {
+      console.log(line);
+    });
+  });
+}

From 3a35a7a48f3d8a52b2c79ead79cfd7db0a1bc30d Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Wed, 29 Jul 2026 00:56:56 +0100
Subject: [PATCH 10/24] wc implemented

---
 implement-shell-tools/wc/wc.js | 141 +++++++++++++++++++++++++++++++++
 1 file changed, 141 insertions(+)
 create mode 100644 implement-shell-tools/wc/wc.js

diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
new file mode 100644
index 0000000..9635e8e
--- /dev/null
+++ b/implement-shell-tools/wc/wc.js
@@ -0,0 +1,141 @@
+const fs = require("fs");
+const { allowedNodeEnvironmentFlags } = require("process");
+
+const arguments = process.argv;
+const userArguments = arguments.slice(2);
+
+const index = arguments[1].lastIndexOf("/");
+const currentWorkingDirectory = arguments[1].slice(0, index + 1);
+
+const flags = userArguments
+  .filter((argument) => argument.startsWith("-"))
+  .map((argument) => argument.slice(1))
+  .join("");
+
+const flagHandlers = {
+  l: lFlag,
+  w: wFlag,
+  c: cFlag,
+};
+
+const metrics = ["lineCount", "wordCount", "byteSize"];
+const fileNames = userArguments.filter((argument) => !argument.startsWith("-"));
+const allFilesData = [];
+
+extractFilesData();
+addTotals();
+const outputData = structuredClone(allFilesData);
+
+let deleted = false;
+executeFlags();
+printOutput();
+
+function extractFilesData() {
+  fileNames.forEach((fileName) => {
+    const fileData = {};
+    fileData.name = fileName;
+    fileData.text = readFile(fileName);
+    fileData.lineCount = calculateLineCount(fileData.text);
+    fileData.wordCount = calculateWordCount(fileData.text);
+    fileData.byteSize = readByteSize(fileName);
+
+    allFilesData.push(fileData);
+  });
+}
+
+function addTotals() {
+  if (allFilesData.length == 1) {
+    return;
+  }
+  const totalsData = { name: "total" };
+  metrics.forEach((metric) => {
+    let sum = 0;
+    allFilesData.forEach((file) => {
+      sum += file[metric];
+    });
+    totalsData[metric] = sum;
+  });
+  allFilesData.push(totalsData);
+}
+
+function readFile(fileName) {
+  const filePath = currentWorkingDirectory + fileName;
+  return fs.readFileSync(filePath, "utf8").trimEnd();
+}
+
+function calculateLineCount(text) {
+  return text.split("\n").length;
+}
+
+function calculateWordCount(text) {
+  return text.split(/\s+/).length;
+}
+
+function readByteSize(fileName) {
+  return fs.statSync(currentWorkingDirectory + fileName).size;
+}
+
+function executeFlags() {
+  for (const flag of flags) {
+    if (flagHandlers[flag]) {
+      allFilesContents = flagHandlers[flag]();
+    } else {
+      console.error(`wc: illegal option -- ${flag}\nusage: wc [-Lclmw] [file ...]`);
+      process.exit(1);
+    }
+  }
+}
+
+function lFlag() {
+  deleteOutputs();
+  allFilesData.forEach((sourceFile) => {
+    const targetFile = outputData.find((file) => file.name === sourceFile.name);
+    targetFile.lineCount = getIfTrue(sourceFile, "lineCount");
+  });
+}
+
+function wFlag() {
+  deleteOutputs();
+  allFilesData.forEach((sourceFile) => {
+    const targetFile = outputData.find((file) => file.name === sourceFile.name);
+    targetFile.wordCount = getIfTrue(sourceFile, "wordCount");
+  });
+}
+
+function cFlag() {
+  deleteOutputs();
+  allFilesData.forEach((sourceFile) => {
+    const targetFile = outputData.find((file) => file.name === sourceFile.name);
+    targetFile.byteSize = getIfTrue(sourceFile, "byteSize");
+  });
+}
+
+function deleteOutputs() {
+  if (!deleted) {
+    outputData.forEach((file) => {
+      metrics.forEach((metric) => {
+        delete file[metric];
+      });
+    });
+  }
+  deleted = true;
+}
+
+function printOutput() {
+  outputs = [];
+  outputData.forEach((file) => {
+    let outputString = "";
+    metrics.forEach((metric) => {
+      outputString += getIfTrue(file, metric);
+    });
+    outputString += ` ${file.name}`;
+    console.log(outputString);
+  });
+}
+
+function getIfTrue(file, metric) {
+  if (file[metric]) {
+    return String(file[metric]).padStart(8, " ");
+  }
+  return "";
+}

From 085224e36b79d11885b390b6ab7cbb165b1ff481 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Thu, 30 Jul 2026 17:17:26 +0100
Subject: [PATCH 11/24] ls complete

---
 implement-shell-tools/ls/ls.js | 124 +++++++++++++++++++++++++++++++++
 1 file changed, 124 insertions(+)
 create mode 100644 implement-shell-tools/ls/ls.js

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
new file mode 100644
index 0000000..6f11136
--- /dev/null
+++ b/implement-shell-tools/ls/ls.js
@@ -0,0 +1,124 @@
+const fs = require("fs");
+const { allowedNodeEnvironmentFlags } = require("process");
+
+const args = process.argv;
+const userArgs = args.slice(2);
+
+const index = args[1].lastIndexOf("/");
+const currentWorkingDirectory = args[1].slice(0, index);
+
+const flags = userArgs
+  .filter((arg) => arg.startsWith("-"))
+  .map((arg) => arg.slice(1))
+  .join("");
+
+const flagHandlers = {
+  1: Flag1,
+  a: Flaga,
+};
+
+let printInList = false;
+let showAll = false;
+
+const fsItems = userArgs.filter((arg) => !arg.startsWith("-"));
+let dirArgs;
+let fileArgs;
+let outputString = "";
+
+const rawData = fs.readdirSync(currentWorkingDirectory);
+
+checkArgsLength();
+executeFlags();
+filterFilesAndDirs();
+populateOutput();
+print();
+
+function executeFlags() {
+  for (const flag of flags) {
+    if (flagHandlers[flag]) {
+      allFilesContents = flagHandlers[flag]();
+    } else {
+      console.error(
+        `ls: invalid option -- ${flag}\nusage: ls [-@ABCFGHILOPRSTUWXabcdefghiklmnopqrstuvwxy1%,] [--color=when] [-D format] [file ...]`,
+      );
+      process.exit(1);
+    }
+  }
+}
+
+function Flag1() {
+  if (printInList) {
+    outputString = outputString.replaceAll("\t", "\n");
+    outputString = outputString.replaceAll("\n\n", "\n");
+  } else {
+    printInList = true;
+  }
+}
+
+function Flaga() {
+  showAll = true;
+}
+
+function checkArgsLength() {
+  if (fsItems.length == 0) {
+    fsItems.push(".");
+  }
+}
+
+function filterFilesAndDirs() {
+  dirArgs = fsItems.filter((p) => fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
+  fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
+  if (showAll == false) {
+    removeDotFiles(fileArgs);
+  }
+}
+
+function populateOutput() {
+  if (fsItems.length == 1) {
+    fileArgs.forEach((file) => {
+      outputString += file + " ";
+    });
+    dirArgs.forEach((dir) => {
+      outputString += dirOutput(dir);
+    });
+  } else {
+    fileArgs.forEach((file) => {
+      outputString += file + "\t";
+    });
+    dirArgs.forEach((dir) => {
+      outputString += "\n\n" + dir + ":\n" + dirOutput(dir);
+    });
+  }
+}
+
+function dirOutput(dir) {
+  let contents = fs.readdirSync(currentWorkingDirectory + "/" + dir);
+  let outputStr = "";
+  if (showAll) {
+    outputStr += ".\t..\t";
+  } else {
+    for (let i = contents.length - 1; i >= 0; i--) {
+      contents = removeDotFiles(contents);
+    }
+  }
+  contents.forEach((item) => {
+    outputStr += item + "\t";
+  });
+  return outputStr;
+}
+
+function removeDotFiles(fileList) {
+  for (let i = fileList.length - 1; i >= 0; i--) {
+    if (fileList[i][0] == ".") {
+      fileList.splice(i, 1);
+    }
+  }
+  return fileList;
+}
+
+function print() {
+  if (printInList == true) {
+    Flag1();
+  }
+  console.log(outputString.trimEnd());
+}

From b28f41dbb8b34c4594b13b4dd36aee9b001e6ba8 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 31 Jul 2026 03:27:27 +0100
Subject: [PATCH 12/24] remove unused code

---
 implement-shell-tools/ls/ls.js | 2 --
 1 file changed, 2 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 6f11136..8646dfe 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -25,8 +25,6 @@ let dirArgs;
 let fileArgs;
 let outputString = "";
 
-const rawData = fs.readdirSync(currentWorkingDirectory);
-
 checkArgsLength();
 executeFlags();
 filterFilesAndDirs();

From 7d6a2986197f28cce46160941144831353c63a0e Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Wed, 12 Aug 2026 04:21:24 +0100
Subject: [PATCH 13/24] updated eronious boolean in ls

---
 implement-shell-tools/ls/ls.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 8646dfe..0efb21d 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -115,7 +115,7 @@ function removeDotFiles(fileList) {
 }
 
 function print() {
-  if (printInList == true) {
+  if (printInList) {
     Flag1();
   }
   console.log(outputString.trimEnd());

From fce72f0c63b83180ab45dc058314a49e83d63d22 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 06:28:08 +0100
Subject: [PATCH 14/24] updated ls so that data doesn't rely on global
 variables and is passed through functions as arguments - also fixed an if
 boolean

---
 implement-shell-tools/ls/ls.js | 133 ++++++++++++++++++---------------
 1 file changed, 72 insertions(+), 61 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 0efb21d..08af639 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -1,17 +1,6 @@
 const fs = require("fs");
 const { allowedNodeEnvironmentFlags } = require("process");
 
-const args = process.argv;
-const userArgs = args.slice(2);
-
-const index = args[1].lastIndexOf("/");
-const currentWorkingDirectory = args[1].slice(0, index);
-
-const flags = userArgs
-  .filter((arg) => arg.startsWith("-"))
-  .map((arg) => arg.slice(1))
-  .join("");
-
 const flagHandlers = {
   1: Flag1,
   a: Flaga,
@@ -20,81 +9,106 @@ const flagHandlers = {
 let printInList = false;
 let showAll = false;
 
-const fsItems = userArgs.filter((arg) => !arg.startsWith("-"));
-let dirArgs;
-let fileArgs;
-let outputString = "";
+ls(process.argv);
+
+// ----------
+
+function ls(args) {
+  const userArgs = getUserArgs(args);
+  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
+  const fsItems = checkArgsLength(getFsItems(userArgs));
+
+  executeFlags(getFlags(userArgs));
+
+  const dirArgs = getDirArgs(fsItems, currentWorkingDirectory);
+  const fileArgs = getFileArgs(fsItems, currentWorkingDirectory);
+
+  print(populateOutput(fsItems, dirArgs, fileArgs, currentWorkingDirectory));
+}
+
+function getUserArgs(args) {
+  return args.slice(2);
+}
+
+function getFsItems(userArgs) {
+  return userArgs.filter((arg) => !arg.startsWith("-"));
+}
+
+function getCurrentWorkingDirectory(args) {
+  const index = args[1].lastIndexOf("/");
+  return args[1].slice(0, index);
+}
 
-checkArgsLength();
-executeFlags();
-filterFilesAndDirs();
-populateOutput();
-print();
+function getFlags(userArgs) {
+  return userArgs
+    .filter((arg) => arg.startsWith("-"))
+    .map((arg) => arg.slice(1))
+    .join("");
+}
 
-function executeFlags() {
+function executeFlags(flags) {
   for (const flag of flags) {
-    if (flagHandlers[flag]) {
-      allFilesContents = flagHandlers[flag]();
-    } else {
-      console.error(
-        `ls: invalid option -- ${flag}\nusage: ls [-@ABCFGHILOPRSTUWXabcdefghiklmnopqrstuvwxy1%,] [--color=when] [-D format] [file ...]`,
-      );
-      process.exit(1);
-    }
+    if (flagHandlers[flag]) flagHandlers[flag]();
+    else invalidFlagError();
   }
 }
 
-function Flag1() {
-  if (printInList) {
-    outputString = outputString.replaceAll("\t", "\n");
-    outputString = outputString.replaceAll("\n\n", "\n");
-  } else {
-    printInList = true;
-  }
+function invalidFlagError() {
+  console.error(
+    `ls: invalid option -- ${flag}\nusage: ls [-@ABCFGHILOPRSTUWXabcdefghiklmnopqrstuvwxy1%,] [--color=when] [-D format] [file ...]`,
+  );
+  process.exit(1);
+}
+
+function Flag1(outputString) {
+  if (printInList) return outputString.replaceAll("\t", "\n").replaceAll("\n\n", "\n");
+  else printInList = true;
 }
 
 function Flaga() {
   showAll = true;
 }
 
-function checkArgsLength() {
-  if (fsItems.length == 0) {
-    fsItems.push(".");
-  }
+function checkArgsLength(fsItems) {
+  if (fsItems.length == 0) fsItems.push(".");
+  return fsItems;
 }
 
-function filterFilesAndDirs() {
-  dirArgs = fsItems.filter((p) => fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
-  fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
-  if (showAll == false) {
-    removeDotFiles(fileArgs);
-  }
+function getDirArgs(fsItems, currentWorkingDirectory) {
+  return fsItems.filter((p) => fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
+}
+
+function getFileArgs(fsItems, currentWorkingDirectory) {
+  const fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
+  if (showAll == false) removeDotFiles(fileArgs);
+  return fileArgs;
 }
 
-function populateOutput() {
+function populateOutput(fsItems, dirArgs, fileArgs, currentWorkingDirectory) {
+  let outputString = "";
   if (fsItems.length == 1) {
     fileArgs.forEach((file) => {
       outputString += file + " ";
     });
     dirArgs.forEach((dir) => {
-      outputString += dirOutput(dir);
+      outputString += dirOutput(dir, currentWorkingDirectory);
     });
   } else {
     fileArgs.forEach((file) => {
       outputString += file + "\t";
     });
     dirArgs.forEach((dir) => {
-      outputString += "\n\n" + dir + ":\n" + dirOutput(dir);
+      outputString += "\n\n" + dir + ":\n" + dirOutput(dir, currentWorkingDirectory);
     });
   }
+  return outputString;
 }
 
-function dirOutput(dir) {
+function dirOutput(dir, currentWorkingDirectory) {
   let contents = fs.readdirSync(currentWorkingDirectory + "/" + dir);
   let outputStr = "";
-  if (showAll) {
-    outputStr += ".\t..\t";
-  } else {
+  if (showAll) outputStr += ".\t..\t";
+  else {
     for (let i = contents.length - 1; i >= 0; i--) {
       contents = removeDotFiles(contents);
     }
@@ -107,16 +121,13 @@ function dirOutput(dir) {
 
 function removeDotFiles(fileList) {
   for (let i = fileList.length - 1; i >= 0; i--) {
-    if (fileList[i][0] == ".") {
-      fileList.splice(i, 1);
-    }
+    if (fileList[i][0] == ".") fileList.splice(i, 1);
   }
   return fileList;
 }
 
-function print() {
-  if (printInList) {
-    Flag1();
-  }
-  console.log(outputString.trimEnd());
+function print(outputString) {
+  let output = outputString;
+  if (printInList) output = Flag1(output);
+  console.log(output.trimEnd());
 }

From 14d4d3348fd4e49dcb7dcc9ff98bb24125aec158 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 06:36:59 +0100
Subject: [PATCH 15/24] updated flag a

---
 implement-shell-tools/ls/ls.js | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 08af639..967bbc1 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -60,9 +60,8 @@ function invalidFlagError() {
   process.exit(1);
 }
 
-function Flag1(outputString) {
-  if (printInList) return outputString.replaceAll("\t", "\n").replaceAll("\n\n", "\n");
-  else printInList = true;
+function Flag1() {
+  printInList = true;
 }
 
 function Flaga() {
@@ -128,6 +127,10 @@ function removeDotFiles(fileList) {
 
 function print(outputString) {
   let output = outputString;
-  if (printInList) output = Flag1(output);
+  if (printInList) output = makeList(output);
   console.log(output.trimEnd());
 }
+
+function makeList(outputString) {
+  return outputString.replaceAll("\t", "\n").replaceAll("\n\n", "\n");
+}

From 2b981ed488822916544cb4f275f79b8e652ca49a Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 06:51:48 +0100
Subject: [PATCH 16/24] collapsed getuserargs function

---
 implement-shell-tools/ls/ls.js | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 967bbc1..30726c5 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -14,22 +14,18 @@ ls(process.argv);
 // ----------
 
 function ls(args) {
-  const userArgs = getUserArgs(args);
-  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
-  const fsItems = checkArgsLength(getFsItems(userArgs));
+  const userArgs = args.slice(2);
 
   executeFlags(getFlags(userArgs));
 
+  const fsItems = checkArgsLength(getFsItems(userArgs));
+  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
   const dirArgs = getDirArgs(fsItems, currentWorkingDirectory);
   const fileArgs = getFileArgs(fsItems, currentWorkingDirectory);
 
   print(populateOutput(fsItems, dirArgs, fileArgs, currentWorkingDirectory));
 }
 
-function getUserArgs(args) {
-  return args.slice(2);
-}
-
 function getFsItems(userArgs) {
   return userArgs.filter((arg) => !arg.startsWith("-"));
 }

From fa7436b603d8aa92cc71ba6b3a4fce7594df13df Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 16:17:31 +0100
Subject: [PATCH 17/24] rearranged some argument orders in ls

---
 implement-shell-tools/ls/ls.js | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 30726c5..3a6b45b 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -18,12 +18,12 @@ function ls(args) {
 
   executeFlags(getFlags(userArgs));
 
-  const fsItems = checkArgsLength(getFsItems(userArgs));
   const currentWorkingDirectory = getCurrentWorkingDirectory(args);
-  const dirArgs = getDirArgs(fsItems, currentWorkingDirectory);
-  const fileArgs = getFileArgs(fsItems, currentWorkingDirectory);
+  const fsItems = checkArgsLength(getFsItems(userArgs));
+  const dirArgs = getDirArgs(currentWorkingDirectory, fsItems);
+  const fileArgs = getFileArgs(currentWorkingDirectory, fsItems);
 
-  print(populateOutput(fsItems, dirArgs, fileArgs, currentWorkingDirectory));
+  print(populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs));
 }
 
 function getFsItems(userArgs) {
@@ -69,17 +69,17 @@ function checkArgsLength(fsItems) {
   return fsItems;
 }
 
-function getDirArgs(fsItems, currentWorkingDirectory) {
+function getDirArgs(currentWorkingDirectory, fsItems) {
   return fsItems.filter((p) => fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
 }
 
-function getFileArgs(fsItems, currentWorkingDirectory) {
+function getFileArgs(currentWorkingDirectory, fsItems) {
   const fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
   if (showAll == false) removeDotFiles(fileArgs);
   return fileArgs;
 }
 
-function populateOutput(fsItems, dirArgs, fileArgs, currentWorkingDirectory) {
+function populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs) {
   let outputString = "";
   if (fsItems.length == 1) {
     fileArgs.forEach((file) => {

From d4720b18bf4e9d28519819c3b8fea3f1f783dae1 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 16:33:15 +0100
Subject: [PATCH 18/24] added comments to ls

---
 implement-shell-tools/cat/cat.js | 24 ++++++++++++++++-------
 implement-shell-tools/ls/ls.js   | 33 ++++++++++++++++++++------------
 2 files changed, 38 insertions(+), 19 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index e9dcd91..e3097d6 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -47,15 +47,25 @@ function executeFlags() {
 }
 
 function bFlag() {
-  return allFilesContents.map((fileContent) => {
+  const resultFiles = [];
+
+  for (const fileContent of allFilesContents) {
+    const formattedLines = [];
     let lineNumber = 1;
-    return fileContent.map((line, index) => {
-      if (line == "") {
-        return `${line}`;
+
+    for (const line of fileContent) {
+      if (line === "") {
+        formattedLines.push(line);
+      } else {
+        const formattedLine = `${String(lineNumber++).padStart(6, " ")} ${line}`;
+        formattedLines.push(formattedLine);
       }
-      return `${String(lineNumber++).padStart(6, " ")} ${line}`;
-    });
-  });
+    }
+
+    resultFiles.push(formattedLines);
+  }
+
+  return resultFiles;
 }
 
 function nFlag() {
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index 3a6b45b..cb7106a 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -26,14 +26,8 @@ function ls(args) {
   print(populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs));
 }
 
-function getFsItems(userArgs) {
-  return userArgs.filter((arg) => !arg.startsWith("-"));
-}
-
-function getCurrentWorkingDirectory(args) {
-  const index = args[1].lastIndexOf("/");
-  return args[1].slice(0, index);
-}
+//
+// ===== Flag Handling =====
 
 function getFlags(userArgs) {
   return userArgs
@@ -60,10 +54,26 @@ function Flag1() {
   printInList = true;
 }
 
+function makeList(outputString) {
+  return outputString.replaceAll("\t", "\n").replaceAll("\n\n", "\n");
+}
+
 function Flaga() {
   showAll = true;
 }
 
+//
+// ===== Extracting data from arguments =====
+
+function getCurrentWorkingDirectory(args) {
+  const index = args[1].lastIndexOf("/");
+  return args[1].slice(0, index);
+}
+
+function getFsItems(userArgs) {
+  return userArgs.filter((arg) => !arg.startsWith("-"));
+}
+
 function checkArgsLength(fsItems) {
   if (fsItems.length == 0) fsItems.push(".");
   return fsItems;
@@ -79,6 +89,9 @@ function getFileArgs(currentWorkingDirectory, fsItems) {
   return fileArgs;
 }
 
+//
+// ===== Outputting Data =====
+
 function populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs) {
   let outputString = "";
   if (fsItems.length == 1) {
@@ -126,7 +139,3 @@ function print(outputString) {
   if (printInList) output = makeList(output);
   console.log(output.trimEnd());
 }
-
-function makeList(outputString) {
-  return outputString.replaceAll("\t", "\n").replaceAll("\n\n", "\n");
-}

From 5c6442916f947d588d10a7175a13be006ed3dc65 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 16:38:03 +0100
Subject: [PATCH 19/24] further added comments to ls

---
 implement-shell-tools/ls/ls.js | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index cb7106a..f82a977 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -1,18 +1,8 @@
 const fs = require("fs");
 const { allowedNodeEnvironmentFlags } = require("process");
 
-const flagHandlers = {
-  1: Flag1,
-  a: Flaga,
-};
-
-let printInList = false;
-let showAll = false;
-
-ls(process.argv);
-
-// ----------
-
+//
+// ===== ls Procedure =====
 function ls(args) {
   const userArgs = args.slice(2);
 
@@ -28,6 +18,13 @@ function ls(args) {
 
 //
 // ===== Flag Handling =====
+const flagHandlers = {
+  1: Flag1,
+  a: Flaga,
+};
+
+let printInList = false;
+let showAll = false;
 
 function getFlags(userArgs) {
   return userArgs
@@ -63,8 +60,7 @@ function Flaga() {
 }
 
 //
-// ===== Extracting data from arguments =====
-
+// ===== Extracting Data From Arguments =====
 function getCurrentWorkingDirectory(args) {
   const index = args[1].lastIndexOf("/");
   return args[1].slice(0, index);
@@ -90,8 +86,7 @@ function getFileArgs(currentWorkingDirectory, fsItems) {
 }
 
 //
-// ===== Outputting Data =====
-
+// ===== Populating and Outputting Data =====
 function populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs) {
   let outputString = "";
   if (fsItems.length == 1) {
@@ -139,3 +134,7 @@ function print(outputString) {
   if (printInList) output = makeList(output);
   console.log(output.trimEnd());
 }
+
+//
+// ===== Run ls =====
+ls(process.argv);

From 769706f84bbcf72d6b03963921e6c9dbe076d5b5 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 17:59:35 +0100
Subject: [PATCH 20/24] wc refactored

---
 implement-shell-tools/wc/wc.js | 174 ++++++++++++++++-----------------
 1 file changed, 86 insertions(+), 88 deletions(-)

diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
index 9635e8e..aecd11c 100644
--- a/implement-shell-tools/wc/wc.js
+++ b/implement-shell-tools/wc/wc.js
@@ -1,64 +1,92 @@
 const fs = require("fs");
 const { allowedNodeEnvironmentFlags } = require("process");
 
-const arguments = process.argv;
-const userArguments = arguments.slice(2);
+const metrics = ["lineCount", "wordCount", "byteSize"];
+const displayedMetrics = [];
+
+//
+// ===== wc Procedure =====
+function wc(args) {
+  const userArgs = args.slice(2);
 
-const index = arguments[1].lastIndexOf("/");
-const currentWorkingDirectory = arguments[1].slice(0, index + 1);
+  executeFlags(getFlags(userArgs));
 
-const flags = userArguments
-  .filter((argument) => argument.startsWith("-"))
-  .map((argument) => argument.slice(1))
-  .join("");
+  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
+  const fileNames = getFileNames(userArgs);
+
+  const allFilesData = addTotals(extractFilesData(fileNames, currentWorkingDirectory));
+  printOutput(allFilesData);
+}
 
+//
+// ===== Flag Handling =====
 const flagHandlers = {
   l: lFlag,
   w: wFlag,
   c: cFlag,
 };
 
-const metrics = ["lineCount", "wordCount", "byteSize"];
-const fileNames = userArguments.filter((argument) => !argument.startsWith("-"));
-const allFilesData = [];
+function getFlags(userArgs) {
+  return userArgs
+    .filter((arg) => arg.startsWith("-"))
+    .map((arg) => arg.slice(1))
+    .join("");
+}
+
+function executeFlags(flags) {
+  for (const flag of flags) {
+    if (flagHandlers[flag]) flagHandlers[flag]();
+    else invalidFlagError();
+  }
+}
+
+function invalidFlagError() {
+  console.error(`wc: illegal option -- ${flag}\nusage: wc [-Lclmw] [file ...]`);
+  process.exit(1);
+}
+
+function lFlag() {
+  displayedMetrics.push("lineCount");
+}
+
+function wFlag() {
+  displayedMetrics.push("wordCount");
+}
+
+function cFlag() {
+  displayedMetrics.push("byteSize");
+}
+
+//
+// ===== Extracting Data From Arguments =====
+function getCurrentWorkingDirectory(args) {
+  const index = args[1].lastIndexOf("/");
+  return args[1].slice(0, index + 1);
+}
 
-extractFilesData();
-addTotals();
-const outputData = structuredClone(allFilesData);
+function getFileNames(userArgs) {
+  return userArgs.filter((argument) => !argument.startsWith("-"));
+}
 
-let deleted = false;
-executeFlags();
-printOutput();
+//
+// ===== Extracting Files Data =====
+function extractFilesData(fileNames, currentWorkingDirectory) {
+  const allFilesData = [];
 
-function extractFilesData() {
   fileNames.forEach((fileName) => {
     const fileData = {};
     fileData.name = fileName;
-    fileData.text = readFile(fileName);
+    fileData.text = readFile(fileName, currentWorkingDirectory);
     fileData.lineCount = calculateLineCount(fileData.text);
     fileData.wordCount = calculateWordCount(fileData.text);
-    fileData.byteSize = readByteSize(fileName);
+    fileData.byteSize = readByteSize(fileName, currentWorkingDirectory);
 
     allFilesData.push(fileData);
   });
+  return allFilesData;
 }
 
-function addTotals() {
-  if (allFilesData.length == 1) {
-    return;
-  }
-  const totalsData = { name: "total" };
-  metrics.forEach((metric) => {
-    let sum = 0;
-    allFilesData.forEach((file) => {
-      sum += file[metric];
-    });
-    totalsData[metric] = sum;
-  });
-  allFilesData.push(totalsData);
-}
-
-function readFile(fileName) {
+function readFile(fileName, currentWorkingDirectory) {
   const filePath = currentWorkingDirectory + fileName;
   return fs.readFileSync(filePath, "utf8").trimEnd();
 }
@@ -71,71 +99,41 @@ function calculateWordCount(text) {
   return text.split(/\s+/).length;
 }
 
-function readByteSize(fileName) {
+function readByteSize(fileName, currentWorkingDirectory) {
   return fs.statSync(currentWorkingDirectory + fileName).size;
 }
 
-function executeFlags() {
-  for (const flag of flags) {
-    if (flagHandlers[flag]) {
-      allFilesContents = flagHandlers[flag]();
-    } else {
-      console.error(`wc: illegal option -- ${flag}\nusage: wc [-Lclmw] [file ...]`);
-      process.exit(1);
-    }
-  }
-}
-
-function lFlag() {
-  deleteOutputs();
-  allFilesData.forEach((sourceFile) => {
-    const targetFile = outputData.find((file) => file.name === sourceFile.name);
-    targetFile.lineCount = getIfTrue(sourceFile, "lineCount");
-  });
-}
-
-function wFlag() {
-  deleteOutputs();
-  allFilesData.forEach((sourceFile) => {
-    const targetFile = outputData.find((file) => file.name === sourceFile.name);
-    targetFile.wordCount = getIfTrue(sourceFile, "wordCount");
-  });
-}
+function addTotals(allFilesData) {
+  if (allFilesData.length == 1) return allFilesData;
 
-function cFlag() {
-  deleteOutputs();
-  allFilesData.forEach((sourceFile) => {
-    const targetFile = outputData.find((file) => file.name === sourceFile.name);
-    targetFile.byteSize = getIfTrue(sourceFile, "byteSize");
-  });
-}
-
-function deleteOutputs() {
-  if (!deleted) {
-    outputData.forEach((file) => {
-      metrics.forEach((metric) => {
-        delete file[metric];
-      });
+  const totalsData = { name: "total" };
+  metrics.forEach((metric) => {
+    let sum = 0;
+    allFilesData.forEach((file) => {
+      sum += file[metric];
     });
-  }
-  deleted = true;
+    totalsData[metric] = sum;
+  });
+  allFilesData.push(totalsData);
+  return allFilesData;
 }
 
-function printOutput() {
-  outputs = [];
+//
+// ===== Outputting Data =====
+function printOutput(outputData) {
   outputData.forEach((file) => {
     let outputString = "";
     metrics.forEach((metric) => {
-      outputString += getIfTrue(file, metric);
+      if (displayedMetrics.length === 0 || displayedMetrics.includes(metric)) {
+        outputString += String(file[metric]).padStart(8, " ");
+      }
     });
+
     outputString += ` ${file.name}`;
     console.log(outputString);
   });
 }
 
-function getIfTrue(file, metric) {
-  if (file[metric]) {
-    return String(file[metric]).padStart(8, " ");
-  }
-  return "";
-}
+//
+// ===== Run wc =====
+wc(process.argv);

From 65e60aea66eb93582a451691dae116bb24e6eae3 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Fri, 28 Aug 2026 19:09:00 +0100
Subject: [PATCH 21/24] refactored cat

---
 implement-shell-tools/cat/cat.js | 121 +++++++++++++++++--------------
 1 file changed, 68 insertions(+), 53 deletions(-)

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
index e3097d6..6774bee 100644
--- a/implement-shell-tools/cat/cat.js
+++ b/implement-shell-tools/cat/cat.js
@@ -1,83 +1,98 @@
 const fs = require("fs");
 
-const arguments = process.argv;
-const userArguments = arguments.slice(2);
-
-const index = arguments[1].lastIndexOf("/");
-const currentWorkingDirectory = arguments[1].slice(0, index + 1);
-
-const flags = userArguments
-  .filter((argument) => argument.startsWith("-"))
-  .map((argument) => argument.slice(1))
-  .join("");
-
-const flagHandlers = {
-  b: bFlag,
-  n: nFlag,
-};
+//
+// ===== cat Procedure =====
+function cat(args) {
+  const userArgs = args.slice(2);
+  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
+  const fileNames = getFileNames(userArgs, currentWorkingDirectory);
+
+  const allFilesContents = readFiles(fileNames, currentWorkingDirectory);
+  executeFlags(getFlags(userArgs), allFilesContents);
+  printLines(allFilesContents);
+}
 
-const fileNames = userArguments.filter((argument) => !argument.startsWith("-"));
-let allFilesContents = [];
+//
+// ===== Extracting Data From Arguments =====
+function getCurrentWorkingDirectory(args) {
+  const index = args[1].lastIndexOf("/");
+  return args[1].slice(0, index + 1);
+}
 
-readFiles();
-executeFlags();
-printLines();
+function getFileNames(userArgs) {
+  return userArgs.filter((argument) => !argument.startsWith("-"));
+}
 
-function readFiles() {
+function readFiles(fileNames, currentWorkingDirectory) {
+  const allFilesContents = [];
   fileNames.forEach((fileName) => {
-    fileContent = readFile(fileName);
+    fileContent = readFile(fileName, currentWorkingDirectory);
     allFilesContents.push(fileContent.split("\n"));
   });
+  return allFilesContents;
 }
 
-function readFile(fileName) {
+function readFile(fileName, currentWorkingDirectory) {
   const filePath = currentWorkingDirectory + fileName;
   return fs.readFileSync(filePath, "utf8").trimEnd();
 }
 
-function executeFlags() {
+//
+// ===== Flag Handling =====
+const flagHandlers = {
+  b: bFlag,
+  n: nFlag,
+};
+
+function getFlags(userArgs) {
+  return userArgs
+    .filter((arg) => arg.startsWith("-"))
+    .map((arg) => arg.slice(1))
+    .join("");
+}
+
+function executeFlags(flags, allFilesContents) {
   for (const flag of flags) {
-    if (flagHandlers[flag]) {
-      allFilesContents = flagHandlers[flag]();
-    } else {
-      console.error(`cat: illegal option -- ${flag}\nusage: cat [-belnstuv] [file ...]`);
-      process.exit(1);
-    }
+    if (flagHandlers[flag]) flagHandlers[flag](allFilesContents, flags);
+    else invalidFlagError();
   }
 }
 
-function bFlag() {
-  const resultFiles = [];
-
-  for (const fileContent of allFilesContents) {
-    const formattedLines = [];
-    let lineNumber = 1;
+function invalidFlagError() {
+  console.error(`cat: illegal option -- ${flag}\nusage: cat [-belnstuv] [file ...]`);
+  process.exit(1);
+}
 
-    for (const line of fileContent) {
-      if (line === "") {
-        formattedLines.push(line);
-      } else {
-        const formattedLine = `${String(lineNumber++).padStart(6, " ")} ${line}`;
-        formattedLines.push(formattedLine);
+function bFlag(allFilesContents) {
+  let linenumber = 1;
+  allFilesContents.forEach((fileContent) => {
+    fileContent.forEach((line, index) => {
+      if (line !== "") {
+        fileContent[index] = `${String(linenumber).padStart(6, " ")} ${line}`;
+        linenumber += 1;
       }
-    }
-
-    resultFiles.push(formattedLines);
-  }
-
-  return resultFiles;
+    });
+  });
 }
 
-function nFlag() {
-  return allFilesContents.map((fileContent) => {
-    return fileContent.map((line, index) => `${String(index + 1).padStart(6, " ")} ${line}`);
-  });
+function nFlag(allFilesContents, flags) {
+  if (!flags.includes("b")) {
+    allFilesContents.forEach((fileContent) => {
+      fileContent.forEach((line, index) => (fileContent[index] = `${String(index + 1).padStart(6, " ")} ${line}`));
+    });
+  }
 }
 
-function printLines() {
+//
+// ==== Print Output =====
+function printLines(allFilesContents) {
   allFilesContents.forEach((fileContent) => {
     fileContent.forEach((line) => {
       console.log(line);
     });
   });
 }
+
+//
+// ===== Run cat =====
+cat(process.argv);

From efdd20b3a8e99a3ee6f4dfc611e325ef6522f1b5 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Sat, 29 Aug 2026 05:56:28 +0100
Subject: [PATCH 22/24] updated getcwd

---
 implement-shell-tools/ls/ls.js | 8 ++++----
 implement-shell-tools/wc/wc.js | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
index f82a977..ae03453 100644
--- a/implement-shell-tools/ls/ls.js
+++ b/implement-shell-tools/ls/ls.js
@@ -63,7 +63,7 @@ function Flaga() {
 // ===== Extracting Data From Arguments =====
 function getCurrentWorkingDirectory(args) {
   const index = args[1].lastIndexOf("/");
-  return args[1].slice(0, index);
+  return args[1].slice(0, index + 1);
 }
 
 function getFsItems(userArgs) {
@@ -76,11 +76,11 @@ function checkArgsLength(fsItems) {
 }
 
 function getDirArgs(currentWorkingDirectory, fsItems) {
-  return fsItems.filter((p) => fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
+  return fsItems.filter((p) => fs.statSync(currentWorkingDirectory + p).isDirectory());
 }
 
 function getFileArgs(currentWorkingDirectory, fsItems) {
-  const fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + "/" + p).isDirectory());
+  const fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + p).isDirectory());
   if (showAll == false) removeDotFiles(fileArgs);
   return fileArgs;
 }
@@ -108,7 +108,7 @@ function populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs) {
 }
 
 function dirOutput(dir, currentWorkingDirectory) {
-  let contents = fs.readdirSync(currentWorkingDirectory + "/" + dir);
+  let contents = fs.readdirSync(currentWorkingDirectory + dir);
   let outputStr = "";
   if (showAll) outputStr += ".\t..\t";
   else {
diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
index aecd11c..130c347 100644
--- a/implement-shell-tools/wc/wc.js
+++ b/implement-shell-tools/wc/wc.js
@@ -33,9 +33,9 @@ function getFlags(userArgs) {
     .join("");
 }
 
-function executeFlags(flags) {
+function executeFlags(flags, allFilesData) {
   for (const flag of flags) {
-    if (flagHandlers[flag]) flagHandlers[flag]();
+    if (flagHandlers[flag]) flagHandlers[flag](allFilesData);
     else invalidFlagError();
   }
 }

From 61a6eaa6c854a89a3182c01cc5a0a5f3129f8861 Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Sat, 29 Aug 2026 06:41:09 +0100
Subject: [PATCH 23/24] Add .venv to gitignore

---
 implement-cowsay/.gitignore       |  1 +
 implement-cowsay/cow.py           | 18 ++++++++++++++++++
 implement-cowsay/requirements.txt |  1 +
 3 files changed, 20 insertions(+)
 create mode 100644 implement-cowsay/.gitignore
 create mode 100644 implement-cowsay/cow.py
 create mode 100644 implement-cowsay/requirements.txt

diff --git a/implement-cowsay/.gitignore b/implement-cowsay/.gitignore
new file mode 100644
index 0000000..21d0b89
--- /dev/null
+++ b/implement-cowsay/.gitignore
@@ -0,0 +1 @@
+.venv/
diff --git a/implement-cowsay/cow.py b/implement-cowsay/cow.py
new file mode 100644
index 0000000..236f4f3
--- /dev/null
+++ b/implement-cowsay/cow.py
@@ -0,0 +1,18 @@
+import cowsay
+import sys
+import argparse
+
+parser = argparse.ArgumentParser(
+    prog="cowsay",
+    description="Make animals say things",
+)
+
+parser.add_argument("--animal", choices=cowsay.char_names, help="The animal to be saying things.", default="cow")
+parser.add_argument("message", nargs="*", help="The message to say.")
+
+args = parser.parse_args()
+
+if args.animal not in cowsay.char_names:
+    sys.exit(f"Unknown animal: {args.animal!r}. Choose from: {', '.join(cowsay.char_names)}")
+
+cowsay.char_funcs[args.animal](" ".join(args.message))
\ No newline at end of file
diff --git a/implement-cowsay/requirements.txt b/implement-cowsay/requirements.txt
new file mode 100644
index 0000000..c6b9ffd
--- /dev/null
+++ b/implement-cowsay/requirements.txt
@@ -0,0 +1 @@
+cowsay

From eeb4d7a01cba159a49faf3df1e611150adcc62ae Mon Sep 17 00:00:00 2001
From: Alex Jamshidi <alexjamshidi@gmail.com>
Date: Sat, 29 Aug 2026 06:51:46 +0100
Subject: [PATCH 24/24] removed implement shell tools files

---
 implement-shell-tools/cat/cat.js |  98 ----------------------
 implement-shell-tools/ls/ls.js   | 140 -------------------------------
 implement-shell-tools/wc/wc.js   | 139 ------------------------------
 3 files changed, 377 deletions(-)
 delete mode 100644 implement-shell-tools/cat/cat.js
 delete mode 100644 implement-shell-tools/ls/ls.js
 delete mode 100644 implement-shell-tools/wc/wc.js

diff --git a/implement-shell-tools/cat/cat.js b/implement-shell-tools/cat/cat.js
deleted file mode 100644
index 6774bee..0000000
--- a/implement-shell-tools/cat/cat.js
+++ /dev/null
@@ -1,98 +0,0 @@
-const fs = require("fs");
-
-//
-// ===== cat Procedure =====
-function cat(args) {
-  const userArgs = args.slice(2);
-  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
-  const fileNames = getFileNames(userArgs, currentWorkingDirectory);
-
-  const allFilesContents = readFiles(fileNames, currentWorkingDirectory);
-  executeFlags(getFlags(userArgs), allFilesContents);
-  printLines(allFilesContents);
-}
-
-//
-// ===== Extracting Data From Arguments =====
-function getCurrentWorkingDirectory(args) {
-  const index = args[1].lastIndexOf("/");
-  return args[1].slice(0, index + 1);
-}
-
-function getFileNames(userArgs) {
-  return userArgs.filter((argument) => !argument.startsWith("-"));
-}
-
-function readFiles(fileNames, currentWorkingDirectory) {
-  const allFilesContents = [];
-  fileNames.forEach((fileName) => {
-    fileContent = readFile(fileName, currentWorkingDirectory);
-    allFilesContents.push(fileContent.split("\n"));
-  });
-  return allFilesContents;
-}
-
-function readFile(fileName, currentWorkingDirectory) {
-  const filePath = currentWorkingDirectory + fileName;
-  return fs.readFileSync(filePath, "utf8").trimEnd();
-}
-
-//
-// ===== Flag Handling =====
-const flagHandlers = {
-  b: bFlag,
-  n: nFlag,
-};
-
-function getFlags(userArgs) {
-  return userArgs
-    .filter((arg) => arg.startsWith("-"))
-    .map((arg) => arg.slice(1))
-    .join("");
-}
-
-function executeFlags(flags, allFilesContents) {
-  for (const flag of flags) {
-    if (flagHandlers[flag]) flagHandlers[flag](allFilesContents, flags);
-    else invalidFlagError();
-  }
-}
-
-function invalidFlagError() {
-  console.error(`cat: illegal option -- ${flag}\nusage: cat [-belnstuv] [file ...]`);
-  process.exit(1);
-}
-
-function bFlag(allFilesContents) {
-  let linenumber = 1;
-  allFilesContents.forEach((fileContent) => {
-    fileContent.forEach((line, index) => {
-      if (line !== "") {
-        fileContent[index] = `${String(linenumber).padStart(6, " ")} ${line}`;
-        linenumber += 1;
-      }
-    });
-  });
-}
-
-function nFlag(allFilesContents, flags) {
-  if (!flags.includes("b")) {
-    allFilesContents.forEach((fileContent) => {
-      fileContent.forEach((line, index) => (fileContent[index] = `${String(index + 1).padStart(6, " ")} ${line}`));
-    });
-  }
-}
-
-//
-// ==== Print Output =====
-function printLines(allFilesContents) {
-  allFilesContents.forEach((fileContent) => {
-    fileContent.forEach((line) => {
-      console.log(line);
-    });
-  });
-}
-
-//
-// ===== Run cat =====
-cat(process.argv);
diff --git a/implement-shell-tools/ls/ls.js b/implement-shell-tools/ls/ls.js
deleted file mode 100644
index ae03453..0000000
--- a/implement-shell-tools/ls/ls.js
+++ /dev/null
@@ -1,140 +0,0 @@
-const fs = require("fs");
-const { allowedNodeEnvironmentFlags } = require("process");
-
-//
-// ===== ls Procedure =====
-function ls(args) {
-  const userArgs = args.slice(2);
-
-  executeFlags(getFlags(userArgs));
-
-  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
-  const fsItems = checkArgsLength(getFsItems(userArgs));
-  const dirArgs = getDirArgs(currentWorkingDirectory, fsItems);
-  const fileArgs = getFileArgs(currentWorkingDirectory, fsItems);
-
-  print(populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs));
-}
-
-//
-// ===== Flag Handling =====
-const flagHandlers = {
-  1: Flag1,
-  a: Flaga,
-};
-
-let printInList = false;
-let showAll = false;
-
-function getFlags(userArgs) {
-  return userArgs
-    .filter((arg) => arg.startsWith("-"))
-    .map((arg) => arg.slice(1))
-    .join("");
-}
-
-function executeFlags(flags) {
-  for (const flag of flags) {
-    if (flagHandlers[flag]) flagHandlers[flag]();
-    else invalidFlagError();
-  }
-}
-
-function invalidFlagError() {
-  console.error(
-    `ls: invalid option -- ${flag}\nusage: ls [-@ABCFGHILOPRSTUWXabcdefghiklmnopqrstuvwxy1%,] [--color=when] [-D format] [file ...]`,
-  );
-  process.exit(1);
-}
-
-function Flag1() {
-  printInList = true;
-}
-
-function makeList(outputString) {
-  return outputString.replaceAll("\t", "\n").replaceAll("\n\n", "\n");
-}
-
-function Flaga() {
-  showAll = true;
-}
-
-//
-// ===== Extracting Data From Arguments =====
-function getCurrentWorkingDirectory(args) {
-  const index = args[1].lastIndexOf("/");
-  return args[1].slice(0, index + 1);
-}
-
-function getFsItems(userArgs) {
-  return userArgs.filter((arg) => !arg.startsWith("-"));
-}
-
-function checkArgsLength(fsItems) {
-  if (fsItems.length == 0) fsItems.push(".");
-  return fsItems;
-}
-
-function getDirArgs(currentWorkingDirectory, fsItems) {
-  return fsItems.filter((p) => fs.statSync(currentWorkingDirectory + p).isDirectory());
-}
-
-function getFileArgs(currentWorkingDirectory, fsItems) {
-  const fileArgs = fsItems.filter((p) => !fs.statSync(currentWorkingDirectory + p).isDirectory());
-  if (showAll == false) removeDotFiles(fileArgs);
-  return fileArgs;
-}
-
-//
-// ===== Populating and Outputting Data =====
-function populateOutput(currentWorkingDirectory, fsItems, dirArgs, fileArgs) {
-  let outputString = "";
-  if (fsItems.length == 1) {
-    fileArgs.forEach((file) => {
-      outputString += file + " ";
-    });
-    dirArgs.forEach((dir) => {
-      outputString += dirOutput(dir, currentWorkingDirectory);
-    });
-  } else {
-    fileArgs.forEach((file) => {
-      outputString += file + "\t";
-    });
-    dirArgs.forEach((dir) => {
-      outputString += "\n\n" + dir + ":\n" + dirOutput(dir, currentWorkingDirectory);
-    });
-  }
-  return outputString;
-}
-
-function dirOutput(dir, currentWorkingDirectory) {
-  let contents = fs.readdirSync(currentWorkingDirectory + dir);
-  let outputStr = "";
-  if (showAll) outputStr += ".\t..\t";
-  else {
-    for (let i = contents.length - 1; i >= 0; i--) {
-      contents = removeDotFiles(contents);
-    }
-  }
-  contents.forEach((item) => {
-    outputStr += item + "\t";
-  });
-  return outputStr;
-}
-
-function removeDotFiles(fileList) {
-  for (let i = fileList.length - 1; i >= 0; i--) {
-    if (fileList[i][0] == ".") fileList.splice(i, 1);
-  }
-  return fileList;
-}
-
-function print(outputString) {
-  let output = outputString;
-  if (printInList) output = makeList(output);
-  console.log(output.trimEnd());
-}
-
-//
-// ===== Run ls =====
-ls(process.argv);
diff --git a/implement-shell-tools/wc/wc.js b/implement-shell-tools/wc/wc.js
deleted file mode 100644
index 130c347..0000000
--- a/implement-shell-tools/wc/wc.js
+++ /dev/null
@@ -1,139 +0,0 @@
-const fs = require("fs");
-const { allowedNodeEnvironmentFlags } = require("process");
-
-const metrics = ["lineCount", "wordCount", "byteSize"];
-const displayedMetrics = [];
-
-//
-// ===== wc Procedure =====
-function wc(args) {
-  const userArgs = args.slice(2);
-
-  executeFlags(getFlags(userArgs));
-
-  const currentWorkingDirectory = getCurrentWorkingDirectory(args);
-  const fileNames = getFileNames(userArgs);
-
-  const allFilesData = addTotals(extractFilesData(fileNames, currentWorkingDirectory));
-  printOutput(allFilesData);
-}
-
-//
-// ===== Flag Handling =====
-const flagHandlers = {
-  l: lFlag,
-  w: wFlag,
-  c: cFlag,
-};
-
-function getFlags(userArgs) {
-  return userArgs
-    .filter((arg) => arg.startsWith("-"))
-    .map((arg) => arg.slice(1))
-    .join("");
-}
-
-function executeFlags(flags, allFilesData) {
-  for (const flag of flags) {
-    if (flagHandlers[flag]) flagHandlers[flag](allFilesData);
-    else invalidFlagError();
-  }
-}
-
-function invalidFlagError() {
-  console.error(`wc: illegal option -- ${flag}\nusage: wc [-Lclmw] [file ...]`);
-  process.exit(1);
-}
-
-function lFlag() {
-  displayedMetrics.push("lineCount");
-}
-
-function wFlag() {
-  displayedMetrics.push("wordCount");
-}
-
-function cFlag() {
-  displayedMetrics.push("byteSize");
-}
-
-//
-// ===== Extracting Data From Arguments =====
-function getCurrentWorkingDirectory(args) {
-  const index = args[1].lastIndexOf("/");
-  return args[1].slice(0, index + 1);
-}
-
-function getFileNames(userArgs) {
-  return userArgs.filter((argument) => !argument.startsWith("-"));
-}
-
-//
-// ===== Extracting Files Data =====
-function extractFilesData(fileNames, currentWorkingDirectory) {
-  const allFilesData = [];
-
-  fileNames.forEach((fileName) => {
-    const fileData = {};
-    fileData.name = fileName;
-    fileData.text = readFile(fileName, currentWorkingDirectory);
-    fileData.lineCount = calculateLineCount(fileData.text);
-    fileData.wordCount = calculateWordCount(fileData.text);
-    fileData.byteSize = readByteSize(fileName, currentWorkingDirectory);
-
-    allFilesData.push(fileData);
-  });
-  return allFilesData;
-}
-
-function readFile(fileName, currentWorkingDirectory) {
-  const filePath = currentWorkingDirectory + fileName;
-  return fs.readFileSync(filePath, "utf8").trimEnd();
-}
-
-function calculateLineCount(text) {
-  return text.split("\n").length;
-}
-
-function calculateWordCount(text) {
-  return text.split(/\s+/).length;
-}
-
-function readByteSize(fileName, currentWorkingDirectory) {
-  return fs.statSync(currentWorkingDirectory + fileName).size;
-}
-
-function addTotals(allFilesData) {
-  if (allFilesData.length == 1) return allFilesData;
-
-  const totalsData = { name: "total" };
-  metrics.forEach((metric) => {
-    let sum = 0;
-    allFilesData.forEach((file) => {
-      sum += file[metric];
-    });
-    totalsData[metric] = sum;
-  });
-  allFilesData.push(totalsData);
-  return allFilesData;
-}
-
-//
-// ===== Outputting Data =====
-function printOutput(outputData) {
-  outputData.forEach((file) => {
-    let outputString = "";
-    metrics.forEach((metric) => {
-      if (displayedMetrics.length === 0 || displayedMetrics.includes(metric)) {
-        outputString += String(file[metric]).padStart(8, " ");
-      }
-    });
-
-    outputString += ` ${file.name}`;
-    console.log(outputString);
-  });
-}
-
-//
-// ===== Run wc =====
-wc(process.argv);