Re: [PATCH] elkscmd/file_utils/cp.c: add options -b, -n, -v, -u and updated usage

[Jody Bruchon <jody@jodybruchon.com>]

On 4/1/2015 7:22 AM, Nils Stec wrote:
+ * Returns -1 if OPT_NOCLOBBER is set and a file is skipped if existent.
...
+		} else if (ISFLAG(OPT_NOCLOBBER)) {
+			return -1;
...
+		retval = copyfile(srcname, destname, 0);
+		if (!retval) goto error_copy;

This causes an error to be returned if someone asks for no clobbering.
Doing what is asked for by the user should never be an error condition
and should return success unless a true error occurred (i.e. write
errors). Here's example output when using the -n switch with GNU 
coreutils 'cp' and testing for any error conditions:

$ ls -l foo bar
bar:
total 0
-rw-r--r-- 1 user user 0 Apr  1 07:31 1
-rw-r--r-- 1 user user 0 Apr  1 07:31 2

foo:
total 12
-rw-r--r-- 1 user user 4 Apr  1 07:31 1
-rw-r--r-- 1 user user 4 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:31 3
$ cp -n foo/* bar/ || echo error
$ cp -n foo/* bar/ && echo success
success
$ ls -l foo bar
bar:
total 4
-rw-r--r-- 1 user user 0 Apr  1 07:31 1
-rw-r--r-- 1 user user 0 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:32 3

foo:
total 12
-rw-r--r-- 1 user user 4 Apr  1 07:31 1
-rw-r--r-- 1 user user 4 Apr  1 07:31 2
-rw-r--r-- 1 user user 4 Apr  1 07:31 3
$