ungetc(3S)           STANDARD I/O FUNCTIONS            ungetc(3S)



NAME
     ungetc - push character back onto input stream

SYNOPSIS
     #include <stdio.h>

     int ungetc (int c, FILE *stream);

DESCRIPTION
     ungetc inserts the character specified by c (converted to an
     unsigned  char)  into  the  buffer  associated with an input
     stream [see intro(3)].  That character, c, will be  returned
     by the next getc(3S) call on that stream.  ungetc returns c,
     and leaves the file corresponding to  stream  unchanged.   A
     successful  call  to  ungetc  clears  the  EOF indicator for
     stream.

     Four bytes of pushback are guaranteed.

     The value of the file position indicator  for  stream  after
     reading or discarding all pushed-back characters will be the
     same as it was before the characters were pushed back.

     If c equals EOF, ungetc  does  nothing  to  the  buffer  and
     returns EOF.

     fseek, rewind [both described  on  fseek(3S)],  and  fsetpos
     erase  the  memory  of inserted characters for the stream on
     which they are applied.

SEE ALSO
     fseek(3S), fsetpos(3C), getc(3S), setbuf(3S), stdio(3S).

DIAGNOSTICS
     ungetc returns EOF if it cannot insert the character.




















          Last change: C Programming Language Utilities         1