xref: /freebsd/usr.bin/stdbuf/stdbuf.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
1 /*-
2  * Copyright (c) 2012 Jeremie Le Hen <jlh@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <err.h>
30 #include <stdio.h>
31 #include <stdlib.h>
32 #include <unistd.h>
33 
34 #define	LIBSTDBUF	"/usr/lib/libstdbuf.so"
35 #define	LIBSTDBUF32	"/usr/lib32/libstdbuf.so"
36 
37 extern char *__progname;
38 
39 static void
40 usage(int s)
41 {
42 
43 	fprintf(stderr, "Usage: %s [-e 0|L|<sz>] [-i 0|L|<sz>] [-o 0|L|<sz>] "
44 	    "<cmd> [args ...]\n", __progname);
45 	exit(s);
46 }
47 
48 int
49 main(int argc, char *argv[])
50 {
51 	char *ibuf, *obuf, *ebuf;
52 	char *preload0, *preload1;
53 	int i;
54 
55 	ibuf = obuf = ebuf = NULL;
56 	while ((i = getopt(argc, argv, "e:i:o:")) != -1) {
57 		switch (i) {
58 		case 'e':
59 			ebuf = optarg;
60 			break;
61 		case 'i':
62 			ibuf = optarg;
63 			break;
64 		case 'o':
65 			obuf = optarg;
66 			break;
67 		case '?':
68 		default:
69 			usage(1);
70 			break;
71 		}
72 	}
73 	argc -= optind;
74 	argv += optind;
75 	if (argc == 0)
76 		exit(0);
77 
78 	if (ibuf != NULL && setenv("_STDBUF_I", ibuf, 1) == -1)
79 		warn("Failed to set environment variable: %s=%s",
80 		    "_STDBUF_I", ibuf);
81 	if (obuf != NULL && setenv("_STDBUF_O", obuf, 1) == -1)
82 		warn("Failed to set environment variable: %s=%s",
83 		    "_STDBUF_O", obuf);
84 	if (ebuf != NULL && setenv("_STDBUF_E", ebuf, 1) == -1)
85 		warn("Failed to set environment variable: %s=%s",
86 		    "_STDBUF_E", ebuf);
87 
88 	preload0 = getenv("LD_PRELOAD");
89 	if (preload0 == NULL)
90 		i = asprintf(&preload1, "LD_PRELOAD=" LIBSTDBUF);
91 	else
92 		i = asprintf(&preload1, "LD_PRELOAD=%s:%s", preload0,
93 		    LIBSTDBUF);
94 
95 	if (i < 0 || putenv(preload1) == -1)
96 		warn("Failed to set environment variable: LD_PRELOAD");
97 
98 	preload0 = getenv("LD_32_PRELOAD");
99 	if (preload0 == NULL)
100 		i = asprintf(&preload1, "LD_32_PRELOAD=" LIBSTDBUF32);
101 	else
102 		i = asprintf(&preload1, "LD_32_PRELOAD=%s:%s", preload0,
103 		    LIBSTDBUF32);
104 
105 	if (i < 0 || putenv(preload1) == -1)
106 		warn("Failed to set environment variable: LD_32_PRELOAD");
107 
108 	execvp(argv[0], argv);
109 	err(2, "%s", argv[0]);
110 }
111