NAME

perror, strerror − system error messages

SYNOPSIS

perror(s)
char ∗s;
#include <string.h>
char ∗
strerror(errnum)
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 returns a pointer to the corresponding message string. 

The perror() function finds the error message corresponding to the current value of the global variable errno (intro(2)) and writes it, followed by a newline, to the standard error file descriptor.  If the argument string is non-NULL, it is prepended to the message string and separated 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 error messages are stored in a data file now rather than an in memory array.  See syserror(5). 

SEE ALSO

mkerrlst(1), intro(2), psignal(3), strerror(3), syserror(3), syserror(5)

BUGS

The strerror() function returns its result in a static buffer which may be overwritten by subsequent calls. 

The array sys_errlist[] and the global sys_nerr are obsolete and should not be used.  They have, for the time being, been placed in an object library liberrlst.a. 

4th Berkeley Distribution  —  March 21, 1996