BSD 4_1_snap release

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

/* @(#)filbuf.c 4.3 (Berkeley) 5/19/81 */
#include        <stdio.h>
char    *malloc();

_filbuf(iop)
register FILE *iop;
{
       static char smallbuf[_NFILE];

       if (iop->_flag & _IORW)
               iop->_flag |= _IOREAD;

       if ((iop->_flag&_IOREAD) == 0)
               return(EOF);
       if (iop->_flag&_IOSTRG)
               return(EOF);
tryagain:
       if (iop->_base==NULL) {
               if (iop->_flag&_IONBF) {
                       iop->_base = &smallbuf[fileno(iop)];
                       goto tryagain;
               }
               if ((iop->_base = malloc(BUFSIZ)) == NULL) {
                       iop->_flag |= _IONBF;
                       goto tryagain;
               }
               iop->_flag |= _IOMYBUF;
       }
       if (iop == stdin && (stdout->_flag&_IOLBF))
               fflush(stdout);
       iop->_cnt = read(fileno(iop), iop->_base, iop->_flag&_IONBF?1:BUFSIZ);
       iop->_ptr = iop->_base;
       if (--iop->_cnt < 0) {
               if (iop->_cnt == -1) {
                       iop->_flag |= _IOEOF;
                       if (iop->_flag & _IORW)
                               iop->_flag &= ~_IOREAD;
               } else
                       iop->_flag |= _IOERR;
               iop->_cnt = 0;
               return(-1);
       }
       return(*iop->_ptr++&0377);
}