Chapter Contents |
Previous |
Next |
perror |
Portability: | ISO/ANSI C conforming, UNIX compatible |
SYNOPSIS | |
DESCRIPTION | |
RETURN VALUE | |
EXAMPLE | |
RELATED FUNCTIONS | |
SEE ALSO |
SYNOPSIS |
#include <stdio.h> void perror(const char *prefix);
DESCRIPTION |
perror
writes a diagnostic message to the standard error file,
stderr
. The message is preceded by the
prefix
string, a colon, and a blank. It is followed by a new-line
character.
The text of the message is based on the value of the
external integer
errno
, which is set by
the library when an error or warning condition is detected.
Note:
If the library writes a diagnostic for an error condition, this message is
usually more precise than the message that would be written by
perror
. This is because, in many cases, one value for
errno
corresponds to a number of different conditions, and other information
about the error (for example, the name of a file) is unavailable to
perror
.
The texts of the messages and the precise meanings of
the possible
errno
values are implementation
dependent. The texts and explanations of the SAS/C library messages are provided
in the
SAS/C Software Diagnostic Messages.
RETURN VALUE |
perror
has no return value.
EXAMPLE |
#include <stdio.h> #include <errno.h> main() { FILE *f; quiet(1); /* Suppress library messages. */ f = fopen("myfile","r"); if (!f) if (errno == ENFOUND) fprintf(stderr, "Error in input phase: myfile not found.\n"); else perror("error in input phase"); quiet(0); /* Allow messages again. */ }
RELATED FUNCTIONS |
SEE ALSO |
Chapter Contents |
Previous |
Next |
Top of Page |
Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.