STDBUF(1)               FreeBSD General Commands Manual              STDBUF(1)

NAME
     stdbuf - change standard streams initial buffering

SYNOPSIS
     stdbuf [-e bufdef] [-i bufdef] [-o bufdef] [command [...]]

DESCRIPTION
     stdbuf is used to change the initial buffering of standard input,
     standard output and/or standard error streams for command.  It relies on
     libstdbuf(3) which is loaded and configured by stdbuf through environment
     variables.

     The options are as follows:

     -e bufdef
             Set initial buffering of the standard error stream for command as
             defined by bufdef (see BUFFER DEFINITION).

     -i bufdef
             Set initial buffering of the standard input stream for command as
             defined by bufdef (see BUFFER DEFINITION).

     -o bufdef
             Set initial buffering of the standard output stream for command
             as defined by bufdef (see BUFFER DEFINITION).

BUFFER DEFINITION
     Buffer definition is the same as in libstdbuf(3):

           "0"   unbuffered

           "L"   line buffered

           "B"   fully buffered with the default buffer size

           size  fully buffered with a buffer of size bytes (suffixes 'k', 'M'
                 and 'G' are accepted)

EXAMPLES
     In the following example, the stdout stream of the awk(1) command will be
     fully buffered by default because it does not refer to a terminal.
     stdbuf is used to force it to be line-buffered so vmstat(8)'s output will
     not stall until the full buffer fills.

           # vmstat 1 | stdbuf -o L awk '$2 > 1 || $3 > 1' | cat -n

SEE ALSO
     libstdbuf(3), setvbuf(3)

HISTORY
     The stdbuf utility first appeared in FreeBSD 8.4.

AUTHORS
     The original idea of the stdbuf command comes from Padraig Brady who
     implemented it in the GNU coreutils.  Jeremie Le Hen implemented it on
     FreeBSD.

FreeBSD 13.1-RELEASE-p6         April 28, 2012         FreeBSD 13.1-RELEASE-p6