rev flags & options

Basic usage

Reverse each line of a file character by character.

rev file.txt

Pipe usage

Reverse text from stdin.

echo "hello world" | rev

Reverse each line

Each line is reversed independently.

printf "abc\n123\nxyz\n" | rev

Extract file extension

Common trick: get the last field by reversing, cutting, and reversing again.

echo "archive.tar.gz" | rev | cut -d. -f1 | rev

Get last path component

echo "/usr/local/bin/python3" | rev | cut -d/ -f1 | rev

Check for palindromes

word="racecar"; [ "$(echo $word | rev)" = "$word" ] && echo "palindrome"