lib/stdio/setvbuf.c

   1 /*
   2  * setbuf.c - control buffering of a stream
   3  */
   4 /* $Id$ */
   5
   6 #include        <stdio.h>
   7 #include        <stdlib.h>
   8 #include        "loc_incl.h"
   9
  10 extern void (*_clean)(void);
  11
  12 int
  13 setvbuf(register FILE *stream, char *buf, int mode, size_t size)
  14 {
  15         int retval = 0;
  16
  17         _clean = __cleanup;
  18         if (mode != _IOFBF && mode != _IOLBF && mode != _IONBF)
  19                 return EOF;
  20
  21         if (stream->_buf && io_testflag(stream,_IOMYBUF) )
  22                 free((void *)stream->_buf);
  23
  24         stream->_flags &= ~(_IOMYBUF | _IONBF | _IOLBF);
  25
  26         if (buf && size <= 0) retval = EOF;
  27         if (!buf && (mode != _IONBF)) {
  28                 if (size <= 0 || (buf = (char *) malloc(size)) == NULL) {
  29                         retval = EOF;
  30                 } else {
  31                         stream->_flags |= _IOMYBUF;
  32                 }
  33         }
  34
  35         stream->_buf = (unsigned char *) buf;
  36
  37         stream->_count = 0;
  38         stream->_flags |= mode;
  39         stream->_ptr = stream->_buf;
  40
  41         if (!buf) {
  42                 stream->_bufsiz = 1;
  43         } else {
  44                 stream->_bufsiz = size;
  45         }
  46
  47         return retval;
  48 }