libexplain  1.4.D001
Functions
libexplain/message/errno/malloc.c File Reference
#include <libexplain/ac/stdlib.h>
#include <libexplain/buffer/errno/malloc.h>
#include <libexplain/malloc.h>

Go to the source code of this file.

Functions

void explain_message_errno_malloc (char *message, int message_size, int errnum, size_t size)

Function Documentation

void explain_message_errno_malloc ( char *  message,
int  message_size,
int  errnum,
size_t  size 
)

The explain_message_errno_malloc function is used to obtain an explanation of an error returned by the malloc(3) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail.

This function is intended to be used in a fashion similar to the following example:

 void *result = malloc(size);
 if (!result)
 {
     int err = errno;
     char message[3000];
     explain_message_errno_malloc(message, sizeof(message), err, size);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_malloc_or_die function.

Parameters:
messageThe location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.
message_sizeThe size in bytes of the location in which to store the returned message.
errnumThe error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.
sizeThe original size, exactly as passed to the malloc(3) system call.

Definition at line 26 of file malloc.c.