crx_std.c

来自「这是用C编写IMAP源代码」· C语言 代码 · 共 38 行

/*
 * Program:	Exclusive create of a file
 *
 * Author:	Mark Crispin
 *		Networks and Distributed Computing
 *		Computing & Communications
 *		University of Washington
 *		Administration Building, AG-44
 *		Seattle, WA  98195
 *		Internet: [e-mail]
 *
 * Date:	17 December 1999
 * Last Edited:	17 Devember 2001
 * 
 * The IMAP toolkit provided in this Distribution is
 * Copyright 2001 University of Washington.
 * The full text of our legal notices is contained in the file called
 * CPYRIGHT, included with this Distribution.
 */

/* Exclusive create of a file
 * Accepts: file name
 * Return: T if success, NIL if failed, -1 if retry
 */

long crexcl (char *name)
{
  int i;
  int mask = umask (0);
  long ret = LONGT;
				/* try to get the lock */
  if ((i = open (name,O_WRONLY|O_CREAT|O_EXCL,(int) lock_protection)) < 0)
    ret = (errno == EEXIST) ? -1 : NIL;
  else close (i);		/* made the file, now close it */
  umask (mask);			/* restore previous mask */
  return LONGT;			/* success */
}