diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/libc/stdio/setbuf.3 | 4 | ||||
| -rw-r--r-- | lib/libstdbuf/Makefile | 12 | ||||
| -rw-r--r-- | lib/libstdbuf/libstdbuf.3 | 102 | ||||
| -rw-r--r-- | lib/libstdbuf/stdbuf.c | 115 |
5 files changed, 234 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile index 876dbb8..2bff80a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -104,6 +104,7 @@ SUBDIR= ${SUBDIR_ORDERED} \ ${_libsmdb} \ ${_libsmutil} \ libstand \ + libstdbuf \ libstdthreads \ ${_libtelnet} \ ${_libthr} \ diff --git a/lib/libc/stdio/setbuf.3 b/lib/libc/stdio/setbuf.3 index be88034..d02d7ea 100644 --- a/lib/libc/stdio/setbuf.3 +++ b/lib/libc/stdio/setbuf.3 @@ -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 , diff --git a/lib/libstdbuf/Makefile b/lib/libstdbuf/Makefile new file mode 100644 index 0000000..cf65e4f --- /dev/null +++ b/lib/libstdbuf/Makefile @@ -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> diff --git a/lib/libstdbuf/libstdbuf.3 b/lib/libstdbuf/libstdbuf.3 new file mode 100644 index 0000000..c60ffd7 --- /dev/null +++ b/lib/libstdbuf/libstdbuf.3 @@ -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 . diff --git a/lib/libstdbuf/stdbuf.c b/lib/libstdbuf/stdbuf.c new file mode 100644 index 0000000..1b5d39a --- /dev/null +++ b/lib/libstdbuf/stdbuf.c @@ -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); +} |
