1 /*
2 * Close stdin, move stdout to a non-standard descriptor, and print.
3 *
4 * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "tests.h"
31
32 #include <assert.h>
33 #include <errno.h>
34 #include <stdarg.h>
35 #include <stdio.h>
36 #include <unistd.h>
37
38 static ssize_t
write_retry(int fd,const void * buf,size_t count)39 write_retry(int fd, const void *buf, size_t count)
40 {
41 ssize_t rc;
42
43 do {
44 errno = 0;
45 rc = write(fd, buf, count);
46 } while (rc == -1 && EINTR == errno);
47
48 if (rc <= 0)
49 perror_msg_and_fail("write");
50
51 return rc;
52 }
53
54 static void
write_loop(int fd,const char * buf,size_t count)55 write_loop(int fd, const char *buf, size_t count)
56 {
57 ssize_t offset = 0;
58
59 while (count > 0) {
60 ssize_t block = write_retry(fd, &buf[offset], count);
61
62 offset += block;
63 count -= (size_t) block;
64 }
65 }
66
67 void
tprintf(const char * fmt,...)68 tprintf(const char *fmt, ...)
69 {
70 static int initialized;
71 if (!initialized) {
72 assert(dup2(1, 3) == 3);
73 assert(close(1) == 0);
74 (void) close(0);
75 initialized = 1;
76 }
77
78 va_list p;
79 va_start(p, fmt);
80
81 static char buf[65536];
82 int len = vsnprintf(buf, sizeof(buf), fmt, p);
83 if (len < 0)
84 perror_msg_and_fail("vsnprintf");
85 assert((unsigned) len < sizeof(buf));
86
87 write_loop(3, buf, len);
88
89 va_end(p);
90 }
91