perror#
Synopsis#
#include <stdio.h>
void perror(const char *s);
Status#
Partially implemented
Conformance#
IEEE Std 1003.1-2017
Description#
The perror()
function shall map the error number accessed through the symbol errno
to a language-dependent error
message, which shall be written to the standard error stream as follows:
First (if s is not a
null
pointer and the character pointed to by s is not thenull
byte), the string pointed to by s followed by a<colon>
and a<space>
.Then an error message string followed by a
<newline>
.
The contents of the error message strings shall be the same as those returned by strerror()
with argument errno
.
The
perror()
function shall mark for update the last data modification and last file status change timestamps of the file
associated with the standard error stream at some time between its successful completion and exit()
, abort()
, or the
completion of fflush()
or fclose()
on stderr.
The perror()
function shall not change the orientation of the standard error stream.
On error, perror()
shall set the error indicator for the stream to which stderr points, and shall set errno
to
indicate the error.
Since no value is returned, an application wishing to check for error situations should call clearerr(stderr)
before
calling perror()
, then if ferror(stderr)
returns non-zero, the value of errno
indicates which error occurred.
Return value#
The perror()
function shall not return a value.
Errors#
Refer to fputc()
Tests#
Untested
Known bugs#
None