BSD 4_1c_2 release

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

/* @(#)ungetc.c 4.1 (Berkeley) 12/21/80 */
#include <stdio.h>

ungetc(c, iop)
register FILE *iop;
{
       if (c == EOF)
               return(-1);
       if ((iop->_flag&_IOREAD)==0 || iop->_ptr <= iop->_base)
               if (iop->_ptr == iop->_base && iop->_cnt==0)
                       *iop->_ptr++;
               else
                       return(-1);
       iop->_cnt++;
       *--iop->_ptr = c;
       return(0);
}