West Midlands | 26 March SDC | Iswat Bello | Sprint 4 | implement shell tools in python

[Iswanna]

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Self checklist

• I have titled my PR with Region | Cohort | FirstName LastName | Sprint | Assignment Title
• My changes meet the requirements of the task
• I have tested my changes
• My changes follow the style guide

Changelist

In this PR, I implemented three core Unix shell utilities in Python: cat, ls, and wc.

cat/cat.py

• Python implementation of file concatenation utility
• -n/--number flag: number all output lines
• -b/--number-nonblank flag: number only non-empty lines
• Support single and multiple file arguments
• Read files with UTF-8 encoding
• Proper error handling with exit codes

ls/ls.py

• Python implementation of directory listing
• -1/--one-per-line flag: list one file per line
• -a/--all flag: show hidden files (dotfiles)
• Colour directories in blue using ANSI escape codes
• Sort entries case-insensitively
• Support custom directory path (default to current directory)
• Proper error handling

wc/wc.py

• Python implementation of word count utility
• -l/--lines flag: print line counts
• -w/--words flag: print word counts
• -c/--bytes flag: print byte counts
• Read from stdin when no files provided
• Support multiple files with totals row
• Byte counts calculated from raw file bytes for accuracy
• Right-justified column formatting (4-char width)
• Proper file not found error handling