truncate(1) User Commands truncate(1)
NAME
truncate - shrink or extend the size of a file to the specified size
SYNOPSIS
truncate OPTION... FILE...
DESCRIPTION
Shrink or extend the size of each FILE to the specified size
A FILE argument that does not exist is created.
If a FILE is larger than the specified size, the extra data is lost.
If a FILE is shorter, it is extended and the sparse extended part
(hole) reads as zero bytes.
Mandatory arguments to long options are mandatory for short options
too.
-c, --no-create
do not create any files
-o, --io-blocks
treat SIZE as number of IO blocks instead of bytes
-r, --reference=RFILE
base size on RFILE
-s, --size=SIZE
set or adjust the file size by SIZE bytes
--help display this help and exit
--version
output version information and exit
The SIZE argument is an integer and optional unit (example: 10K is
10*1024). Units are K,M,G,T,P,E,Z,Y,R,Q (powers of 1024) or KB,MB,...
(powers of 1000). Binary prefixes can be used, too: KiB=K, MiB=M, and
so on.
SIZE may also be prefixed by one of the following modifying characters:
'+' extend by, '-' reduce by, '<' at most, '>' at least, '/' round down
to multiple of, '%' round up to multiple of.
AUTHOR
Written by Padraig Brady.
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
truncate(1), truncate(1)
Full documentation <https://www.gnu.org/software/coreutils/truncate>
or available locally via: info '(coreutils) truncate invocation'
GNU coreutils 9.10 March 2026 truncate(1)
coreutils 9.10 - Generated Thu Apr 2 18:43:17 CDT 2026