less

terminal pager program used to view the contents of text files one

TLDR

View a file

$ less [file]

View a file with line numbers

$ less -N [file]

Search for a pattern after opening

$ /[pattern]

View the output of a command

$ [command] | less

Follow a file as it grows (like tail -f)

$ less +F [file]

Open a file at a specific line

$ less +[line_number] [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.

PARAMETERS

-N, --LINE-NUMBERS

Display line numbers at the beginning of each line

-S, --chop-long-lines

Chop long lines instead of wrapping

-i, --ignore-case

Ignore case in searches (unless pattern has uppercase)

-I, --IGNORE-CASE

Ignore case in searches unconditionally

-F, --quit-if-one-screen

Exit immediately if entire file fits on first screen

-R, --RAW-CONTROL-CHARS

Output raw control characters (preserves colors)

-X, --no-init

Don't clear the screen on exit

-g, --hilite-search

Highlight only the current match, not all matches

-n, --line-numbers

Suppress line numbers (for performance)

Follow mode, scroll forward and wait for more data

+ command

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

-p pattern

Start at first occurrence of pattern

-o file

Copy input to file (when reading from pipe)

NAVIGATION

Space, f, PgDn

Forward one window

b, PgUp

Backward one window

d, u

Forward/backward half window

j, k or Arrow keys

Forward/backward one line

g, G

Go to beginning/end of file

/ pattern

Search forward for pattern

? pattern

Search backward for pattern

n, N

Repeat search forward/backward

Quit

Display help

INSTALL

sudo apt install less

sudo dnf install less

sudo pacman -S less

sudo apk add less

sudo zypper install less

brew install less

nix profile install nixpkgs#less

CAVEATS

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.

HISTORY

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.