ocaml/otherlibs/unix/read.c

38 lines
1.4 KiB
C

/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License. */
/* */
/***********************************************************************/
/* $Id$ */
#include <string.h>
#include <mlvalues.h>
#include <memory.h>
#include <signals.h>
#include "unixsupport.h"
value unix_read(value fd, value buf, value ofs, value len) /* ML */
{
long numbytes;
int ret;
char iobuf[UNIX_BUFFER_SIZE];
Begin_root (buf);
numbytes = Long_val(len);
if (numbytes > UNIX_BUFFER_SIZE) numbytes = UNIX_BUFFER_SIZE;
enter_blocking_section();
ret = read(Int_val(fd), iobuf, (int) numbytes);
leave_blocking_section();
if (ret == -1) uerror("read", Nothing);
memmove (&Byte(buf, Long_val(ofs)), iobuf, ret);
End_roots();
return Val_int(ret);
}