Newbie Question: Permission Denied

[tommcq]

Ok, I've got a simple little script that I wrote which takes some text, strips out superfluous characters then appends the cleaned up text to file. Like I said, simple. I've been using it without problem for months, up until yesterday that is, when I made the mistake of running it as root. Since then, if I try to run it as under my normal user account, it reaches

  open my $filehandle, ">> $fname" or die $!;
  print $filehandle $data;
  close $filehandle;

and quits with 'Permission denied' and diagnostics reporting 'The setuid emulator in suidperl decided you were up to no good'.

I've done all the obvious stuff with ownership and permissions. Even tried shredding the output file and replacing it with a brand new one but the problem remains. Can somebody give a me a clue? I really don't want to have to fire up the root account every time I run this thing.

For info, I'm using Fedora fc8 with perl 5.8.8 (ie. the one that comes bundled with Fedora).

Thanks in advance,
Tom.

[pc88mxer]

The error is just Permission denied, and you are getting it because you can't write to $fname or $fname doesn't exist and you can't create it.

Just debug the problem a little further by inserting these statements before the call to open():

die "file '$fname' does not exist" unless (-e $fname);
die "file '$fname' is not a regular file" unless (-f $fname);
die "file '$fname' is not writable" unless (-w $fname);

That should tell you what's wrong.

[djp]

It's likely you don't have write permission on the output directory, possibly the permissions changed when you ran as root. If that's the problem, sudo to root and change the permissions back.

[tommcq]

Thanks for taking the time to reply guys, some useful tips there that will be plenty useful in future.

As to the solution for my problem, pc88mxer, your little debugging routine picked it up instantly. It turns out that running as root had changed the ownership and group of the output files to root and although I'd chown'd and chgrp'd the main output file back to my normal account, thanks to my own stupidity, I'd completely forgotten about a little logfile that the script also writes to. It's now fixed and everything is working fine.

Once again, thanks to all,
Tom.

[Anonymous Monk]

or die "Can't open $fname for writing : $!"

[Anonymous Monk]

I've done all the obvious stuff with ownership and permissions.
Such as? Please show us.

Use of suidperl is highly discouraged.

[pc88mxer]

Actually, it's not clear the OP is using suidperl. You'll get that message from use diagnostics even from regular perl whenever you have a Permission denied error.