The less command is a powerful and versatile utility for viewing the contents of text files on Unix-like operating systems. It allows users to navigate through files interactively, making it ideal for examining large log files, configuration files, or any text-based data without loading the entire file into memory.

Essential Less Navigation Commands

Here are some fundamental commands to navigate within the less utility:

• Go to end of file: G
• Go to start of file: g
• Next result (after searching): n
• Previous result (after searching): N
• Move to next file (if multiple files opened): :n
• Move to previous file: :p

Less Search and Filter Commands

less provides robust searching and filtering capabilities:

• Search in file: / (Press Enter to search)
• Filter content: <pattern> (Displays only lines matching the pattern)
• Toggle search highlighting: Alt-u

Less Editing and Following Commands

You can also edit files or follow their changes in real-time:

• To edit the current file in $EDITOR: v
• Follow (tail -f) a file after opening it: F
• To start less in follow-mode: less +F <filename>
• To disable the terminal refresh when exiting: less -X

Less Line Wrapping and Saving

Control how lines are displayed and save output:

• Don't wrap long lines: less -S <filename> or -S within less.
• To save the contents to a file (Method 1 - Only works when input is a pipe): s <filename>
• To save the contents to a file (Method 2 - Works with pipes or files): Type g or <, then | $ (pipe then dollar), then cat > <filename> and press Enter.

Mastering the less command is crucial for efficient command-line work. Its ability to handle large files and provide interactive navigation makes it an indispensable tool for developers and system administrators.