explain_ungetc_or_die man page

explain_ungetc_or_die — push a character back to a stream and report errors

Synopsis

#include <libexplain/ungetc.h>

void explain_ungetc_or_die(int c, FILE *fp);
int explain_ungetc_on_error(int c, FILE *fp);

Description

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

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

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

Return Value

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

The explain_ungetc_on_error function always returns the value return by the wrapped ungetc(3) system call.

Example

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

explain_ungetc_or_die(c, fp);

See Also

ungetc(3)
push a character back to a stream
explain_ungetc(3)
explain ungetc(3) errors
exit(2)
terminate the calling process

Referenced By

explain(3), explain_ungetc(3).