stdbuf - Run COMMAND, with modified buffering operations for its standard
Run COMMAND, with modified buffering operations for its standard streams.
Mandatory arguments to long options are mandatory for short options too.
- -i, --input=MODE
- adjust standard input stream buffering
- -o, --output=MODE
- adjust standard output stream buffering
- -e, --error=MODE
- adjust standard error stream buffering
- display this help and exit
- output version information and exit
If MODE is `L' the corresponding stream will be line buffered. This option is
invalid with standard input.
If MODE is `0' the corresponding stream will be unbuffered.
Otherwise MODE is a number which may be followed by one of the following: KB
1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G, T, P, E, Z, Y. In
this case the corresponding stream will be fully buffered with the buffer size
set to MODE bytes.
NOTE: If COMMAND adjusts the buffering of its standard streams (`tee' does for
e.g.) then that will override corresponding settings changed by `stdbuf'. Also
some filters (like `dd' and `cat' etc.) don't use streams for I/O, and are
thus unaffected by `stdbuf' settings.
tail -f access.log | stdbuf -oL cut -d ' ' -f1 | uniq
This will immedidately display unique entries from access.log
On GLIBC platforms, specifying a buffer size, i.e. using fully buffered mode
will result in undefined operation.
Written by Padraig Brady.
Report stdbuf bugs to firstname.lastname@example.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/
General help using GNU software: <http://www.gnu.org/gethelp/
Report stdbuf translation bugs to <http://translationproject.org/team/
Copyright © 2011 Free Software Foundation, Inc. License GPLv3+: GNU GPL
version 3 or later <http://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.
The full documentation for stdbuf
is maintained as a Texinfo manual. If
programs are properly installed at your
site, the command
- info coreutils 'stdbuf invocation'
should give you access to the complete manual.