some Perl code
If you are looking for a Perl module to interface with Amazon’s S3 hosting service, do not use the Net::Amazon::S3 module. It has an unrealistically huge list of modules on which it’s dependent (one of which is more like a framework — a pain in itself) and you’ll likely never get it installed. The Amazon::S3 module by Timothy Appnel installs without a hitch, and it was based on an earlier version of the Net::Amazon::S3 module.
So apparently something in CPAN on OSX 10.6 (Perl version 5.10.0) causes it to change permissions of the /usr/bin/cpan script, not only removing the executable bit for all, but also setting the write bit (not good).
This results in the common “permission denied” message when someone trys to run CPAN to install some Perl modules:
# cpan -bash: /usr/bin/cpan: Permission denied
For the uninitiated, this permission change will render your CPAN installation completely vulnerable to anyone who logs in (or breaks in) to the system, even standard “normal” user accounts.
You can run this find statement to show all files in a directory (including subdirectories) that are world-writeable:
find . -perm -o+w
In the example below, I’ve paired this with the “exec” argument using ’ls’ to show the permissions and inode number of each file.
# find . -perm -o+w -exec ls -ldi {} \; 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./c2ph 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./corelist 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./cpan 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./cpan2dist 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./cpanp 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./cpanp-run-perl 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./dprofpp 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./enc2xs 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./find2perl 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./h2ph 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./h2xs 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./libnetcfg 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./perlbug 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./perlcc 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./perldoc 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./perlivp 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./perlthanks 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./piconv 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pl2pm 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pod2html 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pod2latex 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pod2man 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pod2text 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pod2usage 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./podchecker 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./podselect 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./psed 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./pstruct 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./ptar 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./ptardiff 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./s2p 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./shasum 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./splain 2491453 -rw-rw-rw- 34 root wheel 807 2009-06-24 02:42 ./xsubpp
As you can see from the output, there are a lot of files that were affected, but you can also see from the inode number that they are all hard links to the same file (good in this case). So, we fix the permissions on one file and we fix them all.
`# chmod 0755 cpan
ls -ld cpan
-rwxr-xr-x 34 root wheel 807 2009-06-24 02:42 cpan
find . -perm -o+w -exec ls -ldi {} ;
#` Life is good again. (Note: this will fix the problems, but not the root cause. I’m too lazy to start looking into CPAN itself to find the root cause, so… I’ll leave it to the smart guys who actually write the code for CPAN to figure that one out.)
And in case you are wondering, yes, my computer’s name is Lorien. What can I say? I’m a LotR nerd. Not too unusual for us techie types.