less

Explanation

The less command is a terminal pager program used to view the contents of a text file one screen at a time. It is faster than cat for large files because it does not need to read the entire file before starting. It also allows both forward and backward navigation.

Basic Syntax

less [OPTION]... FILE...

Common Flags and Options

Flag	Description
-N, --LINE-NUMBERS	Display a line number at the beginning of each line.
-S, --chop-long-lines	Truncate long lines rather than wrapping them.
-I, --IGNORE-CASE	Ignore case in searches.

Keyboard Shortcuts in less

• Space or Page Down: Scroll forward one screen.
• b or Page Up: Scroll backward one screen.
• Enter or Down Arrow: Scroll forward one line.
• Up Arrow: Scroll backward one line.
• /pattern: Search forward for a pattern.
• ?pattern: Search backward for a pattern.
• n: Repeat previous search.
• q: Quit.

Real-world Examples

1. View a large file:

   less /var/log/auth.log

2. View a file with line numbers:

   less -N myfile.txt

3. Pipe output to less for easy viewing:

   dmesg | less