DOKK / manpages / debian 12 / libexplain-dev / explain_fileno_or_die.3.en
explain_fileno_or_die(3) Library Functions Manual explain_fileno_or_die(3)

explain_fileno_or_die - check and reset stream status and report errors

#include <libexplain/fileno.h>

int explain_fileno_or_die(FILE *fp);
int explain_fileno_on_error(FILE *fp);

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

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

The fp, exactly as to be passed to the fileno(3) system call.

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

The explain_fileno_on_error function always returns the value return by the wrapped fileno(3) system call.

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

explain_fileno_or_die(fp);

fileno(3)
check and reset stream status
explain_fileno(3)
explain fileno(3) errors
exit(2)
terminate the calling process

libexplain version 1.4
Copyright (C) 2009 Peter Miller