Text 1529, 87 rader
Skriven 2004-09-28 08:19:45 av Jasen Betts (3:640/1042)
   Kommentar till text 1499 av Robert Couture (1:229/2000)
Ärende: Why doesn't this run?
=============================
Hello Robert.

27 Sep 04 08:39, you wrote to me:

 RC> Hello Jasen.

 RC> 26 Sep 04 14:26, you wrote to me:

 JB|>> you're missing #!/bin/bash at the top, that may make a
 JB|>> difference.

 RC> Yes.  That was pointed out to me.  And I thought that was in there ...
 RC> :)

 RC>>> if [ -e /opt/fido/mail/inbound/secure/nodediff.z?? ] ; then

 JB|>> having more than one nodediff.z?? file present would break it
 JB|>> right there. perhaps

 RC> That /should/ never happen as this done prior to htick whicj moves the
 RC> file to it's final resting place.

suppose it gets delayed upstream of you... and both come therough at the same
time.

 JB|>>   shopt -s nullglob

"globs" are filnename containgin wildcard characters,

in linux (and unix etc) globs are handled by the shell and not (usually) by the
application  when you type "mv *.bak ~/bakfiles" the shell goes looking for
files that match the "*.bak" glob and substitutes their names into the
command-line it passes to mv. This is calles glob expansion.  if it doesn't
find any it normally passes the glob expression itself. (so mv would see "mv
*.bak ~/bakfiles", it would then  make an OS call to try to open (or stat)
"*.bak" and discover that there's no file with that (exact) name an print an
error message for you )

nullglob makes ones that cant be translated to a filename, or list of filenames
dissapear.

 RC> Never heard of this.  What does it do?

 JB|>>   if [ -n "/opt/fido/mail/inbound/secure/nodediff.z??" ] ;then

so if there's two files you get a string containing both (which is not a syntax
error), and if there's none you get an empty string (which comes out as false
in this context)

 RC> Hmmm .... I'll have toi learn what -n does. :)

it asks test (which is the real name of the [ ... ]  command ) to test if the
following string has any characters in it.

Actually "-n" does nothing because that's the default test, do "help test" or
"man bash" (or "info bash") for more info.


so in summary

shopt -s nullglob set the nullglob option in bash

then the test checks to see if the glob caught any files by measugring the
result of expanding the glob.

 JB|>> the user that cron runs the script as has got all the permissions
 JB|>> he needs?

 RC> Of this I am sure.

you say that like it's running as root :)

 JB|>> Is there any evidence that the cron job is even running?

 RC> Oh yes.  It runs for mail tossing and since mail and files have been
 RC> being processed for the last two years or so since I switched the Hub
 RC> to Linux, I would say it is running ;)

bung in some echo statements to help track the progress of the cronjob.
another thing to consider is that the cron job may execute with a different
environment ($PATH etc) to your nornal login shell and that may be causing some
confusion.

Jasen

--- GoldED+/LNX 1.1.4.7
 * Origin:  (3:640/1042)