PERROR

Section: MINTLIB LIBRARY FUNCTIONS (3)
Updated: 3 March 1993
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NAME

perror, errno, sys_errlist, sys_nerr, strerror - system error messages  

SYNOPSIS

#include <stdio.h>

void perror(const char *s);

#include <errno.h>

extern int errno;

extern char *sys_errlist[];

extern int sys_nerr;

#include <string.h>

char *strerror(int errnum);
 

DESCRIPTION

perror produces a message on the standard error output, describing the last error encountered during a call to a system or library function. The argument string s is printed first, then a colon and a blank, then the message and a new-line. (However, if s is NULL or s is an empty string the colon is not printed.) To be of most use, 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. To simplify variant formatting of messages, the array of message strings sys_errlist is provided; errno can be used as an index into this table to get the message string without the new-line. sys_nerr is the number of messages in the table; it should be checked because new error codes may be added to the system before they are added to the table. The string function strerror takes an error code as its argument and returns the corresponding message; since it checks sys_nerr, it may be easier of safer to use than sys_errlist.  

NOTES

On UN*X, the string s may be empty, but may not always be NULL. Not all UN*X or POSIX error codes are supported by the mintlibs.
 

Index

NAME
SYNOPSIS
DESCRIPTION
NOTES

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