libexplain/errno/socket.c File Reference

#include <libexplain/common_message_buffer.h>
#include <libexplain/socket.h>

Go to the source code of this file.

Functions
const char *	explain_errno_socket (int errnum, int domain, int type, int protocol)

---

Function Documentation

const char* explain_errno_socket	(	int	errnum,
		int	domain,
		int	type,
		int	protocol
	)

The explain_errno_socket function is used to obtain an explanation of an error returned by the socket(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.

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

 int fildes = socket(domain, type, protocol);
 if (fildes < 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_socket(err, domain, type,
         protocol));
     exit(EXIT_FAILURE);
 }

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

Parameters:

errnum	The 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.
domain	The original domain, exactly as passed to the socket(2) system call.
type	The original type, exactly as passed to the socket(2) system call.
protocol	The original protocol, exactly as passed to the socket(2) system call.

Returns:

The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note:

This function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

Definition at line 24 of file socket.c.