lolcat
Rainbow coloring for text console display
TLDR
SYNOPSIS
lolcat [options] [file ...]
DESCRIPTION
lolcat concatenates files or standard input to standard output, adding a rainbow color gradient. It works like cat but applies ANSI color codes for a colorful twist to terminal output.Commonly paired with ASCII art generators like figlet or cowsay, lolcat is popular for creating visually striking terminal outputs, system banners, and adding personality to shell scripts.
PARAMETERS
-a, --animate
Animate the rainbow effect-d duration, --duration duration
Animation duration in seconds per line (default: 12)-s speed, --speed speed
Animation speed (default: 20.0)-p spread, --spread spread
Rainbow spread (default: 3.0)-F freq, --freq freq
Rainbow frequency (default: 0.1)-S seed, --seed seed
Rainbow seed, 0 = random (default: 0)-i, --invert
Invert foreground and background-t, --truecolor
Use 24-bit truecolor (default on supported terminals)-f, --force
Force color output even when stdout is not a terminal-h, --help
Display help message-v, --version
Print version and exit
CAVEATS
Requires a terminal that supports ANSI color codes. Animation mode can be CPU-intensive on large files. Color output may not display correctly when piped to commands that don't preserve ANSI codes (use -f flag and ensure the receiving program supports raw control characters).
HISTORY
lolcat was created by busyloop and released as a Ruby gem in 2011. Inspired by similar colorization tools, it quickly gained popularity in the Unix community for its simple but entertaining approach to terminal output. Multiple implementations now exist in various languages including C, Python, and Rust, with the C version (c-lolcat) offering better performance for large files.
