libexplain/errno/setbuffer.c File Reference

#include <libexplain/ac/stdio.h>
#include <libexplain/common_message_buffer.h>
#include <libexplain/setbuffer.h>

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Functions
const char *	explain_errno_setbuffer (int errnum, FILE *fp, char *data, size_t size)

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Function Documentation

const char* explain_errno_setbuffer	(	int	errnum,
		FILE *	fp,
		char *	data,
		size_t	size
	)

The explain_errno_setbuffer function is used to obtain an explanation of an error returned by the setbuffer(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.

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.
fp	The original fp, exactly as passed to the setbuffer(3) system call.
data	The original data, exactly as passed to the setbuffer(3) system call.
size	The original size, exactly as passed to the setbuffer(3) 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.

Example:

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

 void result = setbuffer(fp, data, size);
 if (result < 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_setbuffer(err, fp, data, size));
     exit(EXIT_FAILURE);
 }

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

Definition at line 26 of file setbuffer.c.