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

       libexplain version 1.4
       Copyright (C) 2010 Peter Miller

                                                                                        explain_ungetc_or_die(3)

       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.

       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);

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

       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.

ungetc(3)
               push a character back to a stream

       explain_ungetc(3)
               explain ungetc(3) errors

       exit(2) terminate the calling process

       #include <libexplain/ungetc.h>
       void explain_ungetc_or_die(int c, FILE *fp);
       int explain_ungetc_on_error(int c, FILE *fp);