1 /*
2 * Copyright (c) 1990 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms are permitted
6 * provided that the above copyright notice and this paragraph are
7 * duplicated in all such forms and that any documentation,
8 * and/or other materials related to such
9 * distribution and use acknowledge that the software was developed
10 * by the University of California, Berkeley. The name of the
11 * University may not be used to endorse or promote products derived
12 * from this software without specific prior written permission.
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16 */
17
18 /*
19 FUNCTION
20 <<perror>>---print an error message on standard error
21
22 INDEX
23 perror
24 INDEX
25 _perror_r
26
27 SYNOPSIS
28 #include <stdio.h>
29 void perror(char *<[prefix]>);
30
31 void perror( char *<[prefix]>);
32
33 DESCRIPTION
34 Use <<perror>> to print (on standard error) an error message
35 corresponding to the current value of the global variable <<errno>>.
36 Unless you use <<NULL>> as the value of the argument <[prefix]>, the
37 error message will begin with the string at <[prefix]>, followed by a
38 colon and a space (<<: >>). The remainder of the error message is one
39 of the strings described for <<strerror>>.
40
41 The alternate function <<_perror_r>> is a reentrant version. The
42 extra argument <[reent]> is a pointer to a reentrancy structure.
43
44 RETURNS
45 <<perror>> returns no result.
46
47 PORTABILITY
48 ANSI C requires <<perror>>, but the strings issued vary from one
49 implementation to another.
50
51 Supporting OS subroutines required: <<close>>, <<fstat>>, <<isatty>>,
52 <<lseek>>, <<read>>, <<sbrk>>, <<write>>.
53 */
54
55 #define _DEFAULT_SOURCE
56 #define _DEFAULT_SOURCE
57 #include <_ansi.h>
58 #include <stdio.h>
59 #include <string.h>
60 #include "local.h"
61 #include <errno.h>
62
63 #define WRITE_STR(str) \
64 { \
65 const char *p = (str); \
66 size_t len = strlen (p); \
67 while (len) \
68 { \
69 ssize_t len1 = write (fileno (fp), p, len); \
70 if (len1 < 0) \
71 break; \
72 len -= len1; \
73 p += len1; \
74 } \
75 }
76
77 void
perror(const char * s)78 perror (
79 const char *s)
80 {
81 char *error;
82 int dummy;
83 FILE *fp = stderr;
84
85 CHECK_INIT (ptr, fp);
86
87 _newlib_flockfile_start(fp);
88 fflush ( fp);
89 if (s != NULL && *s != '\0')
90 {
91 WRITE_STR (s);
92 WRITE_STR (": ");
93 }
94
95 if ((error = _strerror_r (_REENT_ERRNO(ptr), 1, &dummy)) != NULL)
96 WRITE_STR (error);
97
98 #ifdef __SCLE
99 WRITE_STR ((fp->_flags & __SCLE) ? "\r\n" : "\n");
100 #else
101 WRITE_STR ("\n");
102 #endif
103 fp->_flags &= ~__SOFF;
104 _newlib_flockfile_end(fp);
105 }
106
