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/**************************************************************************/
/* */
/* OCaml */
/* */
/* 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 Lesser General Public License version 2.1, with the */
/* special exception on linking described in the file LICENSE. */
/* */
/**************************************************************************/
#define CAML_INTERNALS
#include <errno.h>
#include <sys/types.h>
#include <caml/mlvalues.h>
#include <caml/alloc.h>
#include <caml/io.h>
#include <caml/signals.h>
#include "caml/unixsupport.h"
#ifdef HAS_UNISTD
#include <unistd.h>
#else
#define SEEK_SET 0
#define SEEK_CUR 1
#define SEEK_END 2
#endif
#ifndef EOVERFLOW
#define EOVERFLOW ERANGE
#endif
static const int seek_command_table[] = {
SEEK_SET, SEEK_CUR, SEEK_END
};
CAMLprim value caml_unix_lseek(value fd, value ofs, value cmd)
{
file_offset ret;
caml_enter_blocking_section();
ret = lseek(Int_val(fd), Long_val(ofs),
seek_command_table[Int_val(cmd)]);
caml_leave_blocking_section();
if (ret == -1) caml_uerror("lseek", Nothing);
if (ret > Max_long) caml_unix_error(EOVERFLOW, "lseek", Nothing);
return Val_long(ret);
}
CAMLprim value caml_unix_lseek_64(value fd, value ofs, value cmd)
{
file_offset ret;
/* [ofs] is an Int64, which is stored as a custom block; we must therefore
extract its contents before dropping the runtime lock, or it might be
moved. */
file_offset ofs_c = File_offset_val(ofs);
caml_enter_blocking_section();
ret = lseek(Int_val(fd), ofs_c, seek_command_table[Int_val(cmd)]);
caml_leave_blocking_section();
if (ret == -1) caml_uerror("lseek", Nothing);
return Val_file_offset(ret);
}
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