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LIBSTDBUF(3)	       FreeBSD Library Functions Manual		  LIBSTDBUF(3)

NAME
     libstdbuf -- preloaded library to change standard streams initial buffer-
     ing

DESCRIPTION
     The libstdbuf library is meant to be preloaded with the LD_PRELOAD	envi-
     ronment variable to as to change the initial buffering of standard	input,
     standard output and standard error	streams.

     Although you may load and configure this library manually,	an utility,
     stdbuf(1),	can be used to run a command with the appropriate environment
     variables.

ENVIRONMENT
     Each stream can be	configured independently through the following envi-
     ronment variables (values are defined below):

	   _STDBUF_I
		 Initial buffering definition for the standard input stream

	   _STDBUF_O
		 Initial buffering definition for the standard output stream

	   _STDBUF_E
		 Initial buffering definition for the standard error stream

     Each variable may take one	of the following values:

	   "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)

EXAMPLE
     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.
     libstdbuf is used to force	it to be line-buffered so vmstat(8)'s output
     will not stall until the full buffer fills.

	   # vmstat 1 |	LD_PRELOAD=/usr/lib/libstdbuf.so \
	       STDBUF_1=L awk '$2 > 1 || $3 > 1' | cat -n

     See also the manpage of stdbuf(1) for a simpler way to do this.

HISTORY
     The libstdbuf library first appeared in FreeBSD 8.4.

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

FreeBSD	9.2			April 28, 2012			   FreeBSD 9.2

NAME | DESCRIPTION | ENVIRONMENT | EXAMPLE | HISTORY | AUTHORS

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