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

3 files changed, 228 insertions, 0 deletions

diff --git a/usr.bin/stdbuf/Makefile b/usr.bin/stdbuf/Makefile
new file mode 100644
index 0000000..ccf139d
--- /dev/null
+++ b/usr.bin/stdbuf/Makefile
@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+PROG=   stdbuf
+SRCS=   stdbuf.c
+
+WARNS?=	6
+
+.include <bsd.prog.mk>
diff --git a/usr.bin/stdbuf/stdbuf.1 b/usr.bin/stdbuf/stdbuf.1
new file mode 100644
index 0000000..2e28740
--- /dev/null
+++ b/usr.bin/stdbuf/stdbuf.1
@@ -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 .
diff --git a/usr.bin/stdbuf/stdbuf.c b/usr.bin/stdbuf/stdbuf.c
new file mode 100644
index 0000000..c6951bb
--- /dev/null
+++ b/usr.bin/stdbuf/stdbuf.c
@@ -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]);
+}