From acf6afe5fdeed2c6e884ee205330640cc64b3265 Mon Sep 17 00:00:00 2001
From: Eric Andersen <andersen@codepoet.org>
Date: Fri, 10 Jan 2003 03:32:11 +0000
Subject: Implement lockf64  -Erik

---
 libc/misc/file/Makefile  |  2 +-
 libc/misc/file/lockf64.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 86 insertions(+), 1 deletion(-)
 create mode 100644 libc/misc/file/lockf64.c

(limited to 'libc/misc/file')

diff --git a/libc/misc/file/Makefile b/libc/misc/file/Makefile
index bb0ea02d8..ed31037bb 100644
--- a/libc/misc/file/Makefile
+++ b/libc/misc/file/Makefile
@@ -24,7 +24,7 @@
 TOPDIR=../../../
 include $(TOPDIR)Rules.mak
 
-CSRC=lockf.c
+CSRC=lockf.c lockf64.c
 COBJS=$(patsubst %.c,%.o, $(CSRC))
 OBJS=$(COBJS)
 
diff --git a/libc/misc/file/lockf64.c b/libc/misc/file/lockf64.c
new file mode 100644
index 000000000..673d11397
--- /dev/null
+++ b/libc/misc/file/lockf64.c
@@ -0,0 +1,85 @@
+/* Copyright (C) 1994, 1996, 1997, 1998, 2000 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>
+
+#ifdef __NR_fcntl64
+#define flock flock64
+#define fcntl fcntl64
+#define F_GETLK F_GETLK64
+#define F_SETLK F_SETLK64
+#endif
+
+/* lockf is a simplified interface to fcntl's locking facilities.  */
+
+int lockf64 (int fd, int cmd, off64_t len64)
+{
+    struct flock fl;
+    off_t len = (off_t) len64;
+
+    if (len64 != (off64_t) len)
+    {
+	/* We can't represent the length.  */
+	__set_errno(EOVERFLOW);
+	return -1;
+    }
+
+    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.  */
+	    fl.l_type = F_RDLCK;
+	    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);
+}
-- 
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