libexplain  1.4.D001
Functions
libexplain/message/pwrite.c File Reference
#include <libexplain/ac/errno.h>
#include <libexplain/ac/unistd.h>
#include <libexplain/pwrite.h>

Go to the source code of this file.

Functions

void explain_message_pwrite (char *message, int message_size, int fildes, const void *data, size_t data_size, off_t offset)

Function Documentation

void explain_message_pwrite ( char *  message,
int  message_size,
int  fildes,
const void *  data,
size_t  data_size,
off_t  offset 
)

The explain_message_pwrite function is used to obtain an explanation of an error returned by the pwrite(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.

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 pwrite(2) system call.
dataThe original data, exactly as passed to the pwrite(2) system call.
data_sizeThe original data_size, exactly as passed to the pwrite(2) system call.
offsetThe original offset, exactly as passed to the pwrite(2) system call.
Example:
This function is intended to be used in a fashion similar to the following example:
 ssize_t result = pwrite(fildes, data, data_size, offset);
 if (result < 0)
 {
     char message[3000];
     explain_message_pwrite(message, sizeof(message), fildes, data,
         data_size, offset);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }
The above code example is available pre-packaged as the explain_pwrite_or_die function.

Definition at line 26 of file pwrite.c.