rev − reverse lines characterwise
rev [option] [file...]
The rev utility copies the specified files to standard output, reversing the order of characters in every line. If no files are specified, standard input is read.
This utility is a line−oriented tool and it uses in−memory allocated buffer for a whole wide−char line. If the input file is huge and without line breaks then allocating the memory for the file may be unsuccessful.
−h, −−help
Display help text and exit.
−V, −−version
Print version and exit.
−0, −−zero
Zero termination. Use the byte '\0' as line separator.
tac(1)
For bug reports, use the issue tracker at <https://github.com/util−linux/util−linux/issues>.
The rev command is part of the util−linux package which can be downloaded from Linux Kernel Archive <https://www.kernel.org/pub/linux/utils/util−linux/>.