tac(1) User Commands tac(1)
NAME
tac - concatenate and print files in reverse
SYNOPSIS
tac [OPTION]... [FILE]...
DESCRIPTION
Write each FILE to standard output, last line first.
With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options
too.
-b, --before
attach the separator before instead of after
-r, --regex
interpret the separator as a regular expression
-s, --separator=STRING
use STRING as the separator instead of newline
--help display this help and exit
--version
output version information and exit
Non-seekable input is buffered to $TMPDIR, defaulting to /tmp.
AUTHOR
Written by Jay Lepreau and David MacKenzie.
REPORTING BUGS
Report bugs to: bug-coreutils@gnu.org
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
Report any translation bugs to <https://translationproject.org/team/>
COPYRIGHT
Copyright © 2026 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
cat(1), rev(1)
Full documentation <https://www.gnu.org/software/coreutils/tac>
or available locally via: info '(coreutils) tac invocation'
GNU coreutils 9.10 March 2026 tac(1)
coreutils 9.10 - Generated Thu Apr 2 18:30:55 CDT 2026