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[unix-history] / usr / src / lib / libc / stdio / ungetc.c

#ifndef lint
static char sccsid[] = "@(#)ungetc.c    5.1 (Berkeley) %G%";
#endif not lint

#include <stdio.h>

ungetc(c, iop)
       register FILE *iop;
{
       if (c == EOF || (iop->_flag & (_IOREAD|_IORW)) == 0 ||
           iop->_ptr == NULL || iop->_base == NULL)
               return (EOF);

       if (iop->_ptr == iop->_base)
               iop->_ptr++;

       iop->_cnt++;
       *--iop->_ptr = c;

       return (c);
}