1 /* Part of publib.
2
3 Copyright (c) 1994-2006 Lars Wirzenius. 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
9 1. Redistributions of source code must retain the above copyright
10 notice, this list of conditions and the following disclaimer.
11
12 2. Redistributions in binary form must reproduce the above
13 copyright notice, this list of conditions and the following
14 disclaimer in the documentation and/or other materials provided
15 with the distribution.
16
17 THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
18 OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19 WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
21 DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
23 GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26 NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29 /*
30 * errormsg.c -- print error message and optionally die
31 *
32 * Part of publib. See man page for more information
33 * "@(#)publib-errormsg:$Id: errormsg.c,v 1.2 1999/03/24 22:29:13 liw Exp $"
34 */
35
36 #include <assert.h>
37 #include <stdlib.h>
38 #include <stdio.h>
39 #include <stdarg.h>
40 #include <string.h>
41 #include <errno.h>
42 #include "publib/errormsg.h"
43
44 static const char *progname = NULL;
45
46 enum __liberror __liberror = __exit_on_error;
47
__set_liberror(enum __liberror i)48 void __set_liberror(enum __liberror i) {
49 __liberror = i;
50 }
51
52
53 /*
54 * Set program name; this is automatically included in the error messages.
55 * Both arguments should point at strings that have static duration, i.e.
56 * they exist until the program terminates (or at least until the last error
57 * message has been printed); this is so that it is not necessary to create
58 * a copy of the name. (The arguments can also be NULL.)
59 *
60 * If the first argument is non-NULL, that is used, otherwise the seconds
61 * argument is used. If both are NULL, no program name is included in the
62 * output. The reason for having two arguments is so that the caller
63 * doesn't have to do the test, and can just call
64 * set_progname(argv[0], "default_name");
65 * (it is valid for argv[0] to be NULL, under ISO C).
66 */
set_progname(const char * argv0,const char * def)67 void set_progname(const char *argv0, const char *def) {
68 if (argv0 != NULL && *argv0 != '\0')
69 progname = argv0;
70 else if (def != NULL && *def != '\0')
71 progname = def;
72 }
73
74
75 /*
76 * Return program name set by set_progname, or an empty string if not set.
77 */
get_progname(void)78 const char *get_progname(void) {
79 return progname != NULL ? progname : "";
80 }
81
82
83 /*
84 * Print error message; if exitp is 1, exit, if 2, abort, after printing
85 * the message. If eno is positive, print error corresponding strerror
86 * message; if eno is -1, use current value of errno.
87 */
errormsg(int do_after,int eno,const char * fmt,...)88 void errormsg(int do_after, int eno, const char *fmt, ...) {
89 va_list args;
90 size_t len;
91 int print_newline, print_progname;
92
93 if (eno == -1) /* this must be done before anything else */
94 eno = errno;
95
96 assert(do_after == 0 || do_after == 1 || do_after == 2);
97 assert(eno >= -1); /* there is no known maximum value for errno */
98 assert(fmt != NULL);
99
100 fflush(NULL); /* output all pending output */
101
102 print_progname = (progname != NULL) && (*progname != '\0');
103
104 if (print_progname)
105 fprintf(stderr, "%s: ", progname);
106
107 va_start(args, fmt);
108 vfprintf(stderr, fmt, args);
109 va_end(args);
110
111 len = strlen(fmt);
112 print_newline = (len > 0) && (fmt[len-1] == '\n');
113
114 if (eno != 0) {
115 if (print_newline) {
116 if (print_progname)
117 fprintf(stderr, "%s: ", progname);
118 fprintf(stderr, "Possible explanation: ");
119 } else {
120 fprintf(stderr, ": ");
121 }
122 fprintf(stderr, "%s\n", strerror(eno));
123 } else {
124 if (!print_newline)
125 fprintf(stderr, "\n"); /* make sure newline ends msg */
126 }
127
128 fflush(stderr);
129
130 switch (do_after) {
131 case 1:
132 exit(EXIT_FAILURE);
133 case 2:
134 abort();
135 }
136 }
137