Years ago I added the -l option to cp. I was looking at it recently and
I saw that it was opening and closing the file even though it never did
anything except link it.
I want to make the following change. Basically it moves the link code
to the start of the function bypassing all that extra work. I think it
is safe but thought that I would pass it by others to make sure that I
am not missing a security hole somewhere.
By the way, a simple test indicates that this change makes an order of
magnitude speedup to the operation.
Index: utils.c
===================================================================
RCS file: /cvsroot/src/bin/cp/utils.c,v
retrieving revision 1.45
diff -u -u -r1.45 utils.c
--- utils.c 29 Feb 2016 04:22:21 -0000 1.45
+++ utils.c 16 Jul 2018 18:38:08 -0000
@@ -99,7 +99,17 @@
int ch, checkch, from_fd, rcount, rval, to_fd, tolnk, wcount;
char *p;
off_t ptotal = 0;
-
+
+ /* if hard linking then simply close the open fds, link and
return */
+ if (lflag) {
+ (void)unlink(to.p_path);
+ if (link(entp->fts_path, to.p_path)) {
+ warn("%s", to.p_path);
+ return (1);
+ }
+ return (0);
+ }
+
if ((from_fd = open(entp->fts_path, O_RDONLY, 0)) == -1) {
warn("%s", entp->fts_path);
return (1);
@@ -164,18 +174,6 @@
rval = 0;
- /* if hard linking then simply close the open fds, link and
return */
- if (lflag) {
- (void)close(from_fd);
- (void)close(to_fd);
- (void)unlink(to.p_path);
- if (link(entp->fts_path, to.p_path)) {
- warn("%s", to.p_path);
- return (1);
- }
- return (0);
- }
-
/*
* There's no reason to do anything other than close the file
* now if it's empty, so let's not bother.
--
D'Arcy J.M. Cain <da...@netbsd.org>
http://www.NetBSD.org/ IM:da...@vex.net
