Re^2: Hijacking perl functions

Replies are listed 'Best First'.
Re^3: Hijacking perl functions by eric256 (Parson) on Jul 29, 2004 at 23:01 UTC
I'm curious why you would want that to be the general case for every chmod call? Wouldn't that be better suited as config_chmod since it is so specialized? ___________ Eric Hodges	[reply]
Re^4: Hijacking perl functions by sweetblood (Prior) on Jul 29, 2004 at 23:37 UTC
I'm sorry if you got the impression that I wanted to globally replace chmod, I don't, ony in this script. Though I can see where it could be useful in other scripts as well. Thanks Sweetblood	[reply]
Re^5: Hijacking perl functions by kryten (Scribe) on Jul 30, 2004 at 10:30 UTC
In which case you probably don't want to be confusing things by replacing chmod. What you want to do is a completely separate operation and should be called something different. Otherwise you'll just confuse everybody. (Including yourself in 6 months time!)	[reply]
Re^3: Hijacking perl functions by Nitrox (Chaplain) on Jul 30, 2004 at 00:13 UTC
If the user doesn't have the proper perms to chmod the old config how is the script going to relace the old one with the new one? -Nitrox	[reply]
Re^4: Hijacking perl functions by mhi (Friar) on Jul 30, 2004 at 06:14 UTC
Under *NIX file systems you need to have perms on the file to chmod it. To delete it (better: to unlink it), you merely need the right perms on the containing directory. To prevent users that have write-perms on a directory from deleting other users' files, you have to set the so-called sticky-bit on the directory.	[reply]
Re^3: Hijacking perl functions by danielcid (Scribe) on Jul 30, 2004 at 12:35 UTC
You will need write permission to replace this file (not only read permission). If your user can't chmod, he will be unable to remove this file too... -DBC	[reply]
Re^4: Hijacking perl functions by mhi (Friar) on Jul 30, 2004 at 19:43 UTC
Not so! Deleting a file under *NIX merely removes a link to the file from the directory. Therefore write permission on the directory is sufficient. No permissions on the file itself are necessary for this, not even read perms, since the file itself is not changed, but only the link leading to it! Try it for yourself.	[reply]
Re^5: Hijacking perl functions by danielcid (Scribe) on Aug 03, 2004 at 13:04 UTC
I can't believe... I tested it here and you are right. I always tought that you needed permissions to the file to delete it. I think it is a big security problem anyway... bash-2.05b$ mkdir test bash-2.05b$ cd test bash-2.05b$ ls -la total 12 drwxr-xr-x 2 dcid devteam 4096 Aug 3 08:57 . drwxr-xr-x 65 dcid devteam 8192 Aug 3 08:57 .. bash-2.05b$ sudo touch file1 bash-2.05b$ ls -la total 12 drwxr-xr-x 2 dcid devteam 4096 Aug 3 08:58 . drwxr-xr-x 65 dcid devteam 8192 Aug 3 08:57 .. -rw-r--r-- 1 root root 0 Aug 3 08:58 file1 bash-2.05b$ rm file1 rm: remove write-protected regular empty file `file1'? y bash-2.05b$ ls bash-2.05b$ ls -la total 12 drwxr-xr-x 2 dcid devteam 4096 Aug 3 08:58 . drwxr-xr-x 65 dcid devteam 8192 Aug 3 08:57 .. bash-2.05b$ sudo mkdir dir1 bash-2.05b$ ls -la total 16 drwxr-xr-x 3 dcid devteam 4096 Aug 3 08:59 . drwxr-xr-x 65 dcid devteam 8192 Aug 3 08:57 .. drwxr-xr-x 2 root root 4096 Aug 3 08:59 dir1 bash-2.05b$ rmdir dir1 bash-2.05b$ ls bash-2.05b$ ls -la total 12 drwxr-xr-x 2 dcid devteam 4096 Aug 3 08:59 . drwxr-xr-x 65 dcid devteam 8192 Aug 3 08:57 .. [download] *hum... this is why we need the sticky bit in the "tmp" dir.. I completely forgot about it.	[reply] [d/l]


good chemistry is complicated, and a little bit messy -LW
	PerlMonks