Import stdbuf(1) and the shared library it relies on.

This tool changes the default buffering behaviour of standard
stdio streams.

It only works on dynamic binaries.  To make it work for static
ones it would require cluttering stdio because there no single
entry point.

PR:		166660
Reviewed by:	current@, jhb
Approved by:	kib (mentor)
MFC after:	1 week
This commit is contained in:
Jeremie Le Hen 2012-04-28 20:52:20 +00:00
parent 64cc18cc01
commit 6486b015fc
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=234772
9 changed files with 463 additions and 0 deletions

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@ -104,6 +104,7 @@ SUBDIR= ${SUBDIR_ORDERED} \
${_libsmdb} \
${_libsmutil} \
libstand \
libstdbuf \
libstdthreads \
${_libtelnet} \
${_libthr} \

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@ -83,6 +83,9 @@ normally does) it is line buffered.
The standard error stream
.Dv stderr
is always unbuffered.
Note that these defaults maybe be altered using the
.Xr stdbuf 1
utility.
.Pp
The
.Fn setvbuf
@ -177,6 +180,7 @@ function returns what the equivalent
.Fn setvbuf
would have returned.
.Sh SEE ALSO
.Xr stdbuf 1 ,
.Xr fclose 3 ,
.Xr fopen 3 ,
.Xr fread 3 ,

12
lib/libstdbuf/Makefile Normal file
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@ -0,0 +1,12 @@
# $FreeBSD$
.include <bsd.own.mk>
LIB= stdbuf
SRCS= stdbuf.c
SHLIB_MAJOR= 1
MAN= libstdbuf.3
WARNS?= 6
.include <bsd.lib.mk>

102
lib/libstdbuf/libstdbuf.3 Normal file
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@ -0,0 +1,102 @@
.\" Copyright (c) 2012 Jeremie Le Hen <jlh@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code and documentation must retain the above
.\" copyright notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd April 28, 2012
.Dt LIBSTDBUF 3
.Os
.Sh NAME
.Nm libstdbuf
.Nd preloaded library to change standard streams initial buffering
.Sh DESCRIPTION
The
.Nm
library is meant to be preloaded with the
.Ev LD_PRELOAD
environment variable to as to change the initial buffering
of standard input, standard output and standard error streams.
.Pp
Although you may load and configure this library manually,
an utility,
.Xr stdbuf 1 ,
can be used to run a command with the appropriate environment variables.
.Sh ENVIRONMENT
Each stream can be configured indepentently through the following
environment variables (values are defined below):
.Bl -tag -width size -offset indent
.It Ev _STDBUF_I
Initial buffering definition for the standard input stream
.It Ev _STDBUF_O
Initial buffering definition for the standard output stream
.It Ev _STDBUF_E
Initial buffering definition for the standard error stream
.El
.Pp
Each variable may take one of the following values:
.Bl -tag -width size -offset indent
.It Qq 0
unbuffered
.It Qq L
line buffered
.It Qq B
fully buffered with the default buffer size
.It Ar size
fully buffered with a buffer of
.Ar size
bytes (suffixes 'k', 'M' and 'G' are accepted)
.El
.Sh EXAMPLE
In the following example, the stdout stream of the
.Xr awk 1
command
will be fully buffered by default because it does not refer
to a terminal.
.Nm
is used to force it to be line-buffered so
.Xr vmstat 8 Ns 's
output will not stall until the full buffer fills.
.Bd -literal -offset indent
# vmstat 1 | LD_PRELOAD=/usr/lib/libstdbuf.so \\
STDBUF_1=L awk '$2 > 1 || $3 > 1' | cat -n
.Ed
.Pp
See also the manpage of
.Xr stdbuf 1
for a simpler way to do this.
.Sh HISTORY
The
.Nm
library first appeared in
.Fx 8.4 .
.Sh AUTHORS
.An -nosplit
The original idea of the
.Nm
command comes from
.An Padraig Brady
who implemented it in the GNU coreutils.
.An Jeremie Le Hen
implemented it on
.Fx .

115
lib/libstdbuf/stdbuf.c Normal file
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@ -0,0 +1,115 @@
/*-
* Copyright (c) 2012 Jeremie Le Hen <jlh@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
static const char *
stream_name(FILE *s)
{
if (s == stdin)
return "stdin";
if (s == stdout)
return "stdout";
if (s == stderr)
return "stderr";
/* This should not happen. */
abort();
}
static void
change_buf(FILE *s, const char *bufmode)
{
char *unit;
size_t bufsize;
int mode;
bufsize = 0;
if (bufmode[0] == '0' && bufmode[1] == '\0')
mode = _IONBF;
else if (bufmode[0] == 'L' && bufmode[1] == '\0')
mode = _IOLBF;
else if (bufmode[0] == 'B' && bufmode[1] == '\0') {
mode = _IOFBF;
bufsize = 0;
} else {
/*
* This library being preloaded, depending on libutil
* would lead to excessive namespace pollution.
* Thus we do not use expand_number().
*/
errno = 0;
bufsize = strtol(bufmode, &unit, 0);
if (errno == EINVAL || errno == ERANGE || unit == bufmode)
warn("Wrong buffer mode '%s' for %s", bufmode,
stream_name(s));
switch (*unit) {
case 'G':
bufsize *= 1024 * 1024 * 1024;
break;
case 'M':
bufsize *= 1024 * 1024;
break;
case 'k':
bufsize *= 1024;
break;
case '\0':
break;
default:
warnx("Unknown suffix '%c' for %s", *unit,
stream_name(s));
return;
}
mode = _IOFBF;
}
if (setvbuf(s, NULL, mode, bufsize) != 0)
warn("Cannot set buffer mode '%s' for %s", bufmode,
stream_name(s));
}
__attribute__ ((constructor)) static void
stdbuf(void)
{
char *i_mode, *o_mode, *e_mode;
i_mode = getenv("_STDBUF_I");
o_mode = getenv("_STDBUF_O");
e_mode = getenv("_STDBUF_E");
if (e_mode != NULL)
change_buf(stderr, e_mode);
if (i_mode != NULL)
change_buf(stdin, i_mode);
if (o_mode != NULL)
change_buf(stdout, o_mode);
}

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@ -143,6 +143,7 @@ SUBDIR= alias \
sockstat \
split \
stat \
stdbuf \
su \
systat \
tabs \

8
usr.bin/stdbuf/Makefile Normal file
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@ -0,0 +1,8 @@
# $FreeBSD$
PROG= stdbuf
SRCS= stdbuf.c
WARNS?= 6
.include <bsd.prog.mk>

116
usr.bin/stdbuf/stdbuf.1 Normal file
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@ -0,0 +1,116 @@
.\" Copyright (c) 2012 Jeremie Le Hen <jlh@FreeBSD.org>
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code and documentation must retain the above
.\" copyright notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD$
.\"
.Dd April 28, 2012
.Dt STDBUF 1
.Os
.Sh NAME
.Nm stdbuf
.Nd change standard streams initial buffering
.Sh SYNOPSIS
.Nm
.Op Fl e Ar bufdef
.Op Fl i Ar bufdef
.Op Fl o Ar bufdef
.Op Ar command Op ...
.Sh DESCRIPTION
.Nm
is used to change the initial buffering of standard input,
standard output and/or standard error streams for
.Ar command .
It relies on
.Xr libstdbuf 3
which is loaded and configured by
.Nm
through environment variables.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl e Ar bufdef
Set initial buffering of the standard error stream for
.Ar command
as defined by
.Ar bufdef
.Pq see Sx BUFFER DEFINITION .
.It Fl i Ar bufdef
Set initial buffering of the standard input stream for
.Ar command
as defined by
.Ar bufdef
.Pq see Sx BUFFER DEFINITION .
.It Fl o Ar bufdef
Set initial buffering of the standard output stream for
.Ar command
as defined by
.Ar bufdef
.Pq see Sx BUFFER DEFINITION .
.El
.Sh BUFFER DEFINITION
Buffer definition is the same as in
.Xr libstdbuf 3 :
.Bl -tag -width size -offset indent
.It Qq 0
unbuffered
.It Qq L
line buffered
.It Qq B
fully buffered with the default buffer size
.It Ar size
fully buffered with a buffer of
.Ar size
bytes (suffixes 'k', 'M' and 'G' are accepted)
.El
.Sh EXAMPLES
In the following example, the stdout stream of the
.Xr awk 1
command
will be fully buffered by default because it does not refer
to a terminal.
.Nm
is used to force it to be line-buffered so
.Xr vmstat 8 Ns 's
output will not stall until the full buffer fills.
.Bd -literal -offset indent
# vmstat 1 | stdbuf -o L awk '$2 > 1 || $3 > 1' | cat -n
.Ed
.Sh SEE ALSO
.Xr libstdbuf 3 ,
.Xr setvbuf 3
.Sh HISTORY
The
.Nm
utility first appeared in
.Fx 8.4 .
.Sh AUTHORS
.An -nosplit
The original idea of the
.Nm
command comes from
.An Padraig Brady
who implemented it in the GNU coreutils.
.An Jeremie Le Hen
implemented it on
.Fx .

104
usr.bin/stdbuf/stdbuf.c Normal file
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@ -0,0 +1,104 @@
/*-
* Copyright (c) 2012 Jeremie Le Hen <jlh@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#define LIBSTDBUF "/usr/lib/libstdbuf.so"
extern char *__progname;
static void
usage(int s)
{
fprintf(stderr, "Usage: %s [-e 0|L|<sz>] [-i 0|L|<sz>] [-o 0|L|<sz>] "
"<cmd> [args ...]\n", __progname);
exit(s);
}
int
main(int argc, char *argv[])
{
char *ibuf, *obuf, *ebuf;
char *preload0, *preload1;
int i;
ibuf = obuf = ebuf = NULL;
while ((i = getopt(argc, argv, ":e:i:o:")) != -1) {
switch (i) {
case 'e':
ebuf = optarg;
break;
case 'i':
ibuf = optarg;
break;
case 'o':
obuf = optarg;
break;
case ':':
warnx("Missing argument for option -%c", optopt);
usage(1);
break;
case '?':
default:
warnx("Unknown option: %c", optopt);
usage(1);
break;
}
}
argc -= optind;
argv += optind;
if (argc < 2)
usage(0);
if (ibuf != NULL && setenv("_STDBUF_I", ibuf, 1) == -1)
warn("Failed to set environment variable: %s=%s",
"_STDBUF_I", ibuf);
if (obuf != NULL && setenv("_STDBUF_O", obuf, 1) == -1)
warn("Failed to set environment variable: %s=%s",
"_STDBUF_O", obuf);
if (ebuf != NULL && setenv("_STDBUF_E", ebuf, 1) == -1)
warn("Failed to set environment variable: %s=%s",
"_STDBUF_E", ebuf);
preload0 = getenv("LD_PRELOAD");
if (preload0 == NULL)
i = asprintf(&preload1, "LD_PRELOAD=" LIBSTDBUF);
else
i = asprintf(&preload1, "LD_PRELOAD=%s:%s", preload0,
LIBSTDBUF);
if (i < 0 || putenv(preload1) == -1)
warn("Failed to set environment variable: %s", preload1);
execvp(argv[0], argv);
err(2, "%s", argv[0]);
}