4.3BSD - /usr/src/lib/libc/stdio/filbuf.c

   1: /*
   2:  * Copyright (c) 1980 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #if defined(LIBC_SCCS) && !defined(lint)
   8: static char sccsid[] = "@(#)filbuf.c	5.3 (Berkeley) 3/9/86";
   9: #endif LIBC_SCCS and not lint
  10: 
  11: #include    <stdio.h>
  12: #include    <sys/types.h>
  13: #include    <sys/stat.h>
  14: char    *malloc();
  15: 
  16: _filbuf(iop)
  17: register FILE *iop;
  18: {
  19:     int size;
  20:     struct stat stbuf;
  21:     extern char *_smallbuf;
  22:     char c;
  23: 
  24:     if (iop->_flag & _IORW)
  25:         iop->_flag |= _IOREAD;
  26: 
  27:     if ((iop->_flag&_IOREAD) == 0)
  28:         return(EOF);
  29:     if (iop->_flag&(_IOSTRG|_IOEOF))
  30:         return(EOF);
  31: tryagain:
  32:     if (iop->_base==NULL) {
  33:         if (iop->_flag&_IONBF) {
  34:             iop->_base = _smallbuf ? &_smallbuf[fileno(iop)] : &c;
  35:             goto tryagain;
  36:         }
  37:         if (fstat(fileno(iop), &stbuf) < 0 || stbuf.st_blksize <= NULL)
  38:             size = BUFSIZ;
  39:         else
  40:             size = stbuf.st_blksize;
  41:         if ((iop->_base = malloc(size)) == NULL) {
  42:             iop->_flag |= _IONBF;
  43:             goto tryagain;
  44:         }
  45:         iop->_flag |= _IOMYBUF;
  46:         iop->_bufsiz = size;
  47:     }
  48:     if (iop == stdin) {
  49:         if (stdout->_flag&_IOLBF)
  50:             fflush(stdout);
  51:         if (stderr->_flag&_IOLBF)
  52:             fflush(stderr);
  53:     }
  54:     iop->_cnt = read(fileno(iop), iop->_base,
  55:         iop->_flag & _IONBF ? 1 : iop->_bufsiz);
  56:     iop->_ptr = iop->_base;
  57:     if (iop->_flag & _IONBF && iop->_base == &c)
  58:         iop->_base = NULL;
  59:     if (--iop->_cnt < 0) {
  60:         if (iop->_cnt == -1) {
  61:             iop->_flag |= _IOEOF;
  62:             if (iop->_flag & _IORW)
  63:                 iop->_flag &= ~_IOREAD;
  64:         } else
  65:             iop->_flag |= _IOERR;
  66:         iop->_cnt = 0;
  67:         return(EOF);
  68:     }
  69:     return(*iop->_ptr++&0377);
  70: }

Defined functions

Defined variables