STRERROR(3) BSD Programmer's Manual STRERROR(3)NAME
perror, strerror, sys_errlist, sys_nerr - system error messages
SYNOPSIS
#include <stdio.h>
void
perror(const char *string);
extern const char * const sys_errlist[];
extern int sys_nerr;
#include <string.h>
char *
strerror(int errnum);
DESCRIPTION
The strerror() and perror() functions look up the error message string
corresponding to an error number.
The strerror() function accepts an error number argument errnum and re-
turns a pointer to the corresponding message string.
The perror() function finds the error message corresponding to the cur-
rent value of the global variable errno (intro(2)) and writes it, fol-
lowed by a newline, to the standard error file descriptor. If the argu-
ment string is non-NULL, it is prepended to the message string and sepa-
rated from it by a colon and space (`: '). If string is NULL, only the
error message string is printed.
If errnum is not a recognized error number, the error message string will
contain ``Unknown error: '' followed by the error number in decimal.
The message strings can be accessed directly using the external array
sys_errlist. The external value sys_nerr contains a count of the messages
in sys_errlist. The use of these variables is deprecated; strerror()
should be used instead.
SEE ALSOintro(2), err(3), psignal(3)HISTORY
The strerror() and perror() functions first appeared in 4.4BSD.
BUGS
For unknown error numbers, the strerror() function will return its result
in a static buffer which may be overwritten by subsequent calls.
4th Berkeley Distribution June 9, 1993 1
