REV(1)                  FreeBSD General Commands Manual                 REV(1)

NAME
     rev - reverse lines of a file

SYNOPSIS
     rev [file ...]

DESCRIPTION
     The rev utility copies the specified files to the standard output,
     reversing the order of characters in every line.  If no files are
     specified, the standard input is read.

EXAMPLES
     Reverse the text from stdin:

           $ echo -e "reverse \t these\ntwo lines" | rev
           eseht    esrever
           senil owt

FreeBSD 13.1-RELEASE-p6          June 27, 2020         FreeBSD 13.1-RELEASE-p6