libexplain  1.4.D001
Functions
libexplain/message/getsockopt.c File Reference
#include <libexplain/ac/errno.h>
#include <libexplain/ac/sys/socket.h>
#include <libexplain/getsockopt.h>

Go to the source code of this file.

Functions

void explain_message_getsockopt (char *message, int message_size, int fildes, int level, int name, void *data, socklen_t *data_size)

Function Documentation

void explain_message_getsockopt ( char *  message,
int  message_size,
int  fildes,
int  level,
int  name,
void *  data,
socklen_t *  data_size 
)

The explain_message_getsockopt function is used to obtain an explanation of an error returned by the getsockopt(2) 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.

The errno global variable will be used to obtain the error value to be decoded.

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

 if (getsockopt(fildes, level, name, data, data_size) < 0)
 {
     char message[3000];
     explain_message_getsockopt(message, sizeof(message), fildes, level,
         name, data, data_size);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_getsockopt_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.
fildesThe original fildes, exactly as passed to the getsockopt(2) system call.
levelThe original level, exactly as passed to the getsockopt(2) system call.
nameThe original name, exactly as passed to the getsockopt(2) system call.
dataThe original data, exactly as passed to the getsockopt(2) system call.
data_sizeThe original data_size, exactly as passed to the getsockopt(2) system call.

Definition at line 26 of file getsockopt.c.