1/*
2 * Copyright (c) 1999-2017 The strace developers.
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 * 3. The name of the author may not be used to endorse or promote products
14 *    derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#ifdef HAVE_CONFIG_H
29# include "config.h"
30#endif
31
32#include <errno.h>
33#include <stdarg.h>
34#include <string.h>
35#include <stdio.h>
36#include <stdlib.h>
37
38#include "error_prints.h"
39
40#ifndef HAVE_PROGRAM_INVOCATION_NAME
41extern char *program_invocation_name;
42#endif
43
44static void
45verror_msg(int err_no, const char *fmt, va_list p)
46{
47	char *msg;
48
49	fflush(NULL);
50
51	/* We want to print entire message with single fprintf to ensure
52	 * message integrity if stderr is shared with other programs.
53	 * Thus we use vasprintf + single fprintf.
54	 */
55	msg = NULL;
56	if (vasprintf(&msg, fmt, p) >= 0) {
57		if (err_no)
58			fprintf(stderr, "%s: %s: %s\n",
59				program_invocation_name, msg, strerror(err_no));
60		else
61			fprintf(stderr, "%s: %s\n",
62				program_invocation_name, msg);
63		free(msg);
64	} else {
65		/* malloc in vasprintf failed, try it without malloc */
66		fprintf(stderr, "%s: ", program_invocation_name);
67		vfprintf(stderr, fmt, p);
68		if (err_no)
69			fprintf(stderr, ": %s\n", strerror(err_no));
70		else
71			putc('\n', stderr);
72	}
73	/* We don't switch stderr to buffered, thus fprintf(stderr)
74	 * always flushes its output and this is not necessary: */
75	/* fflush(stderr); */
76}
77
78void
79error_msg(const char *fmt, ...)
80{
81	va_list p;
82	va_start(p, fmt);
83	verror_msg(0, fmt, p);
84	va_end(p);
85}
86
87void
88error_msg_and_die(const char *fmt, ...)
89{
90	va_list p;
91	va_start(p, fmt);
92	verror_msg(0, fmt, p);
93	die();
94}
95
96void
97error_msg_and_help(const char *fmt, ...)
98{
99	if (fmt != NULL) {
100		va_list p;
101		va_start(p, fmt);
102		verror_msg(0, fmt, p);
103	}
104	fprintf(stderr, "Try '%s -h' for more information.\n",
105		program_invocation_name);
106	die();
107}
108
109void
110perror_msg(const char *fmt, ...)
111{
112	va_list p;
113	va_start(p, fmt);
114	verror_msg(errno, fmt, p);
115	va_end(p);
116}
117
118void
119perror_msg_and_die(const char *fmt, ...)
120{
121	va_list p;
122	va_start(p, fmt);
123	verror_msg(errno, fmt, p);
124	die();
125}
126