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.\" DO NOT MODIFY THIS FILE! It was generated by help2man 1.50.1.
.TH STDBUF "1" "February 2026" "GNU coreutils 9.10" "User Commands"
.SH NAME
stdbuf \-
Run COMMAND, with modified buffering operations for its standard streams.
.SH SYNOPSIS
.B stdbuf
\fI\,OPTION\/\fR... \fI\,COMMAND\/\fR
.SH DESCRIPTION
.\" Add any additional description here
.PP
Run COMMAND, with modified buffering operations for its standard streams.
.PP
Mandatory arguments to long options are mandatory for short options too.
.TP
\X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#stdbuf-i'\fB\-i, \-\-input=\,MODE\fP\X'tty: link'\/\fR
adjust standard input stream buffering
.TP
\X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#stdbuf-o'\fB\-o, \-\-output=\,MODE\fP\X'tty: link'\/\fR
adjust standard output stream buffering
.TP
\X'tty: link https://www.gnu.org/software/coreutils/manual/coreutils.html#stdbuf-e'\fB\-e, \-\-error=\,MODE\fP\X'tty: link'\/\fR
adjust standard error stream buffering
.TP
\X'tty: link https://www.gnu.org/software/coreutils/stdbuf#stdbuf--help'\fB\-\-help\fP\X'tty: link'
display this help and exit
.TP
\X'tty: link https://www.gnu.org/software/coreutils/stdbuf#stdbuf--version'\fB\-\-version\fP\X'tty: link'
output version information and exit
.PP
If MODE is 'L' the corresponding stream will be line buffered.
This option is invalid with standard input.
.PP
If MODE is '0' the corresponding stream will be unbuffered.
.PP
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,R,Q.
Binary prefixes can be used, too: KiB=K, MiB=M, and so on.
In this case the corresponding stream will be fully buffered with the buffer
size set to MODE bytes.
.PP
NOTE: If COMMAND adjusts the buffering of its standard streams ('tee' does
for example) then that will override corresponding changes by 'stdbuf'.
Also some filters (like 'dd' and 'cat' etc.) don't use streams for I/O,
and are thus unaffected by 'stdbuf' settings.
.SS "Exit status:"
.TP
125
if the stdbuf command itself fails
.TP
126
if COMMAND is found but cannot be invoked
.TP
127
if COMMAND cannot be found
.TP
\-
the exit status of COMMAND otherwise
.SH EXAMPLES
.B tail -f access.log | stdbuf -oL cut -d \(aq \(aq -f1 | uniq
.br
This will immediately display unique entries from access.log
.SH BUGS
On GLIBC platforms, specifying a buffer size, i.e., using fully buffered mode
will result in undefined operation.
.SH AUTHOR
Written by Padraig Brady.
.SH "REPORTING BUGS"
Report bugs to: bug\-coreutils@gnu.org
.br
GNU coreutils home page: <https://www.gnu.org/software/coreutils/>
.br
General help using GNU software: <https://www.gnu.org/gethelp/>
.br
Report any translation bugs to <https://translationproject.org/team/>
.SH COPYRIGHT
Copyright \(co 2026 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
.br
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
.SH "SEE ALSO"
Full documentation <https://www.gnu.org/software/coreutils/stdbuf>
.br
or available locally via: info \(aq(coreutils) stdbuf invocation\(aq
|
