/* -*-c-*-
*
- * $Id: fdflags.c,v 1.1 1999/07/26 23:16:59 mdw Exp $
+ * $Id$
*
* Manipulates flags on file descriptors
*
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: fdflags.c,v $
- * Revision 1.1 1999/07/26 23:16:59 mdw
- * Manipulate file descriptor flags.
- *
- */
-
/*----- Header files ------------------------------------------------------*/
#include <stdio.h>
int fdflags(int fd, unsigned fbic, unsigned fxor,
unsigned fdbic, unsigned fdxor)
{
- int f;
+ int f, ff;
- if ((f = fcntl(fd, F_GETFL)) == -1 ||
- fcntl(fd, F_SETFL, (f & ~fbic) ^ fxor) == -1 ||
- (f = fcntl(fd, F_GETFD)) == -1 ||
- fcntl(fd, F_SETFD, (f & ~fdbic) ^ fdxor) == -1)
- return (-1);
+ if (fbic || fxor) {
+ if ((f = fcntl(fd, F_GETFL)) == -1)
+ return (-1);
+ ff = (f & ~fbic) ^ fxor;
+ if (f != ff && fcntl(fd, F_SETFL, ff) == -1)
+ return (-1);
+ }
+ if (fdbic || fdxor) {
+ if ((f = fcntl(fd, F_GETFD)) == -1)
+ return (-1);
+ ff = (f & ~fdbic) ^ fdxor;
+ if (f != ff && fcntl(fd, F_SETFD, ff) == -1)
+ return (-1);
+ }
return (0);
}