1PERROR(3P)                 POSIX Programmer's Manual                PERROR(3P)
2
3
4

PROLOG

6       This  manual  page is part of the POSIX Programmer's Manual.  The Linux
7       implementation of this interface may differ (consult the  corresponding
8       Linux  manual page for details of Linux behavior), or the interface may
9       not be implemented on Linux.
10

NAME

12       perror - write error messages to standard error
13

SYNOPSIS

15       #include <stdio.h>
16
17       void perror(const char *s);
18
19

DESCRIPTION

21       The perror() function shall map the error number accessed  through  the
22       symbol  errno  to  a  language-dependent  error message, which shall be
23       written to the standard error stream as follows:
24
25        * First (if s is not a null pointer and the character pointed to by  s
26          is  not  the  null  byte),  the string pointed to by s followed by a
27          colon and a <space>.
28
29        * Then an error message string followed by a <newline>.
30
31       The contents of the error message strings shall be the  same  as  those
32       returned by strerror() with argument errno.
33
34       The  perror() function shall mark the file associated with the standard
35       error stream as having been  written  (st_ctime,  st_mtime  marked  for
36       update)  at  some  time  between  its successful completion and exit(),
37       abort(), or the completion of fflush() or fclose() on stderr.
38
39       The perror() function shall not change the orientation of the  standard
40       error stream.
41

RETURN VALUE

43       The perror() function shall not return a value.
44

ERRORS

46       No errors are defined.
47
48       The following sections are informative.
49

EXAMPLES

51   Printing an Error Message for a Function
52       The  following example replaces bufptr with a buffer that is the neces‐
53       sary size. If an error occurs, the perror() function prints  a  message
54       and the program exits.
55
56
57              #include <stdio.h>
58              #include <stdlib.h>
59              ...
60              char *bufptr;
61              size_t szbuf;
62              ...
63              if ((bufptr = malloc(szbuf)) == NULL) {
64                  perror("malloc"); exit(2);
65              }
66              ...
67

APPLICATION USAGE

69       None.
70

RATIONALE

72       None.
73

FUTURE DIRECTIONS

75       None.
76

SEE ALSO

78       strerror(),   the  Base  Definitions  volume  of  IEEE Std 1003.1-2001,
79       <stdio.h>
80

82       Portions of this text are reprinted and reproduced in  electronic  form
83       from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
84       -- Portable Operating System Interface (POSIX),  The  Open  Group  Base
85       Specifications  Issue  6,  Copyright  (C) 2001-2003 by the Institute of
86       Electrical and Electronics Engineers, Inc and The Open  Group.  In  the
87       event of any discrepancy between this version and the original IEEE and
88       The Open Group Standard, the original IEEE and The Open Group  Standard
89       is  the  referee document. The original Standard can be obtained online
90       at http://www.opengroup.org/unix/online.html .
91
92
93
94IEEE/The Open Group                  2003                           PERROR(3P)
Impressum