strace/tests/tprintf.c
Dmitry V. Levin 536a0353dd tests: add tprintf function to libtests
* tests/tests.h (tprintf): New prototype.
* tests/tprintf.c: New file.
* tests/Makefile.am (libtests_a_SOURCES): Add it.
* tests/mmsg.c: Use tprintf.
2016-01-20 15:17:28 +00:00

91 lines
2.5 KiB
C

/*
* Close stdin, move stdout to a non-standard descriptor, and print.
*
* Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
*/
#include "tests.h"
#include <assert.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <unistd.h>
static ssize_t
write_retry(int fd, const void *buf, size_t count)
{
ssize_t rc;
do {
errno = 0;
rc = write(fd, buf, count);
} while (rc == -1 && EINTR == errno);
if (rc <= 0)
perror_msg_and_fail("write");
return rc;
}
static void
write_loop(int fd, const char *buf, size_t count)
{
ssize_t offset = 0;
while (count > 0) {
ssize_t block = write_retry(fd, &buf[offset], count);
offset += block;
count -= (size_t) block;
}
}
void
tprintf(const char *fmt, ...)
{
static int initialized;
if (!initialized) {
assert(dup2(1, 3) == 3);
assert(close(1) == 0);
(void) close(0);
initialized = 1;
}
va_list p;
va_start(p, fmt);
static char buf[65536];
int len = vsnprintf(buf, sizeof(buf), fmt, p);
if (len < 0)
perror_msg_and_fail("vsnprintf");
assert((unsigned) len < sizeof(buf));
write_loop(3, buf, len);
va_end(p);
}