explain_vfprintf_or_die(3)

formatted output conversion and report errors

Section 3 libexplain-dev bookworm source

Description

explain_vfprintf_or_die

NAME

explain_vfprintf_or_die - formatted output conversion and report errors

SYNOPSIS

#include <libexplain/vfprintf.h>
void explain_vfprintf_or_die(FILE *fp, const char *format, va_list ap);
int explain_vfprintf_on_error(FILE *fp, const char *format, va_list ap);

DESCRIPTION

The explain_vfprintf_or_die function is used to call the vfprintf(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_vfprintf(3) function, and then the process terminates by calling exit(EXIT_FAILURE).

The explain_vfprintf_on_error function is used to call the vfprintf(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_vfprintf(3) function, but still returns to the caller.

	fp		The fp, exactly as to be passed to the vfprintf(3) system call.
	format		The format, exactly as to be passed to the vfprintf(3) system call.
	ap		The ap, exactly as to be passed to the vfprintf(3) system call.

RETURN VALUE

The explain_vfprintf_or_die function only returns on success, see vfprintf(3) for more information. On failure, prints an explanation and exits, it does not return.

The explain_vfprintf_on_error function always returns the value return by the wrapped vfprintf(3) system call.

EXAMPLE

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

explain_vfprintf_or_die(fp, format, ap);