perror(3C) Standard C Library Functions perror(3C)NAME
perror, errno - print system error messages
SYNOPSIS
#include <stdio.h>
void perror(const char *s)
#include <errno.h>
int errno;
DESCRIPTION
The perror() function produces a message on the standard error output
(file descriptor 2) describing the last error encountered during a call
to a system or library function. The argument string s is printed, fol‐
lowed by a colon and a blank, followed by the message and a NEWLINE
character. If s is a null pointer or points to a null string, the
colon is not printed. The argument string should include the name of
the program that incurred the error. The error number is taken from the
external variable errno, which is set when errors occur but not cleared
when non-erroneous calls are made. See intro(2).
In the case of multithreaded applications, the -mt option must be spec‐
ified on the command line at compilation time (see threads(5)). When
the -mt option is specified, errno becomes a macro that enables each
thread to have its own errno. This errno macro can be used on either
side of the assignment as though it were a variable.
USAGE
Messages printed from this function are in the native language speci‐
fied by the LC_MESSAGES locale category. See setlocale(3C).
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Interface Stability │Standard │
├─────────────────────────────┼─────────────────────────────┤
│MT-Level │MT-Safe │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOintro(2), fmtmsg(3C), gettext(3C), setlocale(3C), strerror(3C),
attributes(5), standards(5), threads(5)SunOS 5.10 12 Jul 2007 perror(3C)