Header File 

string.h, stdio.h  

Category 

Memory and String Manipulation Routines 

Prototype 

char *_strerror(const char *s); 

Description 

Builds a customized error message. 

_strerror lets you generate customized error messages; it returns a pointer to a null-terminated string containing an error message.

• If s is null, the return value points to the most recent error message.
• If s is not null, the return value contains s (your customized error message), a colon, a space, the most-recently generated system error message, and a new line. s should be 94 characters or less.

_strerror returns a pointer to a constructed error string. The error message string is constructed in a static buffer that is overwritten with each call to _strerror. 

Example  

#include <stdio.h>
#include <errno.h>
int main(void)
{
   char *buffer;
   buffer = strerror(errno);
   printf("Error: %s\n", buffer);
   return 0;
}

Portability