Module 02: Help & Text Mastery

Why it matters

Linux administration is 80% text processing: reading logs, parsing configs, extracting data. Mastering grep, sed, awk, and find makes you 10x faster. Learning to use man pages and built-in help means you never get stuck. These are the most-used commands after ls and cd.

• man <command> — show manual page (press q to quit)
• <command> --help — quick help summary
• apropos <keyword> — search man pages by keyword
• grep <pattern> <file> — search for pattern in file
• grep -r <pattern> <dir> — recursive search in directory
• sed 's/old/new/' <file> — replace text (stream editor)
• awk '{print $1}' <file> — extract columns
• find <dir> -name <pattern> — find files by name
• head -n 10 <file> — show first 10 lines
• tail -f <file> — follow file in real-time (logs)
• wc -l <file> — count lines