strerror()

Updated: April 19, 2023

Convert an error number into an error message

Synopsis:

#include <string.h>

char* strerror( int errnum );

Arguments:

errnum
The error number that you want the message for. This function works for any valid errno value.

Library:

libc

Use the -l c option to qcc to link against this library. This library is usually included automatically.

Description:

The strerror() function maps the error number contained in errnum to an error message.

Returns:

A pointer to the error message.

Note: Don't modify the string that this function returns.

Examples:

#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <stdlib.h>

int main( void )
{
    FILE *fp;

    fp = fopen( "file.name", "r" );
    if( fp == NULL ) {
        printf( "Unable to open file: %s\n",
            strerror( errno ) );
    }

    return EXIT_SUCCESS;
}

Classification:

ANSI, POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes