mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-15 07:30:13 +00:00
bfce746a87
1998-08-31 15:56 Ulrich Drepper <drepper@cygnus.com> * db2/db_int.h: Use <db.h> instead of "db.h" to find header in include. * include/stdio.h: Add __vsscanf. * libio/stdio.h: Make vfscanf, scanf, and vsscanf available if __USE_ISOC9X. Remove __vsscanf declaration. Always declare fgetpos and fsetpos. * math/math.h: Define isinf as macro. * math/bits/mathcalls.h: Change to declare __isinf all the time. Don't declare scalb for ISO C 9x. * math/tgmath.h: Define fma. Rewrite the underlying macros. * stdlib/stdlib.h: Declare strtof and strtold is __USE_ISOC9X. * sysdeps/unix/sysv/linux/bits/sigcontext.h: Allow inclusion from sys/ucontext.h. * sysdeps/wordsize-32/inttypes.h: Define missing PRI* and SCN* macros. 1998-08-31 Andreas Jaeger <aj@arthur.rhein-neckar.de> * sysdeps/standalone/bits/errno.h (ENOMSG): Remove duplicate. Reported by jreising@frequentis.com [PR libc/767]. 1998-08-31 Andreas Jaeger <aj@arthur.rhein-neckar.de> * io/lockf.c (lockf): Move initilisation of fl.l_whence and fl.l_start at beginning of function. Patch by Geoff. Dash <geoffd@zeta.org.au> [PR libc/769].
71 lines
2.0 KiB
C
71 lines
2.0 KiB
C
/* Copyright (C) 1994, 1996, 1997, 1998 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Library General Public License as
|
|
published by the Free Software Foundation; either version 2 of the
|
|
License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If not,
|
|
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
#include <fcntl.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
|
|
/* lockf is a simplified interface to fcntl's locking facilities. */
|
|
|
|
int
|
|
lockf (int fd, int cmd, off_t len)
|
|
{
|
|
struct flock fl;
|
|
|
|
memset ((char *) &fl, '\0', sizeof (fl));
|
|
|
|
/* lockf is always relative to the current file position. */
|
|
fl.l_whence = SEEK_CUR;
|
|
fl.l_start = 0;
|
|
fl.l_len = len;
|
|
|
|
switch (cmd)
|
|
{
|
|
case F_TEST:
|
|
/* Test the lock: return 0 if FD is unlocked or locked by this process;
|
|
return -1, set errno to EACCES, if another process holds the lock. */
|
|
if (__fcntl (fd, F_GETLK, &fl) < 0)
|
|
return -1;
|
|
if (fl.l_type == F_UNLCK || fl.l_pid == __getpid ())
|
|
return 0;
|
|
__set_errno (EACCES);
|
|
return -1;
|
|
|
|
case F_ULOCK:
|
|
fl.l_type = F_UNLCK;
|
|
cmd = F_SETLK;
|
|
break;
|
|
case F_LOCK:
|
|
fl.l_type = F_WRLCK;
|
|
cmd = F_SETLKW;
|
|
break;
|
|
case F_TLOCK:
|
|
fl.l_type = F_WRLCK;
|
|
cmd = F_SETLK;
|
|
break;
|
|
|
|
default:
|
|
__set_errno (EINVAL);
|
|
return -1;
|
|
}
|
|
|
|
return __fcntl (fd, cmd, &fl);
|
|
}
|