less

View a file

$ less [file]

$ less -N [file]

$ /[pattern]

$ [command] | less

$ less +F [file]

$ less +[line_number] [file]

less [-options] [file ...]

less is a terminal pager program used to view the contents of text files one screen at a time. Unlike more, it allows backward navigation through files and does not require reading the entire file before displaying, making it efficient for large files.
The program provides powerful search capabilities with regular expression support, can display line numbers, and handles multiple files in a single session. It is commonly used as the default pager for manual pages and is invaluable for examining log files and command output.
Less can read from standard input, making it ideal for piping command output. The follow mode (+F) allows real-time monitoring of growing files, similar to tail -f but with the full navigation capabilities of less.

-N, --LINE-NUMBERS

Display line numbers at the beginning of each line

Chop long lines instead of wrapping

Ignore case in searches (unless pattern has uppercase)

Ignore case in searches unconditionally

Exit immediately if entire file fits on first screen

Output raw control characters (preserves colors)

Don't clear the screen on exit

Highlight only the current match, not all matches

Suppress line numbers (for performance)

Follow mode, scroll forward and wait for more data

Run specified command on startup (e.g., +/pattern to search)

Start at first occurrence of pattern

Copy input to file (when reading from pipe)

Space, f, PgDn

Forward one window

Backward one window

Forward/backward half window

Forward/backward one line

Go to beginning/end of file

Search forward for pattern

Search backward for pattern

Repeat search forward/backward

Quit

Display help

Binary files may display incorrectly or cause terminal issues. Very long lines can be slow to render without the -S option. The LESSOPEN and LESSCLOSE environment variables can preprocess files but may pose security risks if not properly configured.

less was written by Mark Nudelman and first released in 1984 as an improved replacement for the Unix more command. The name is a play on the phrase "less is more." It has become a standard utility on Unix-like systems and is the default pager on most Linux distributions. The program continues to be actively maintained with regular updates adding new features and improvements.

more(1), cat(1), tail(1), head(1), most(1)