• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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