On 12/12/07, Steve Bertrand <[EMAIL PROTECTED]> wrote: > I am heavily modifying (re-writing) some Perl scripts that are bundled > within the dialup_admin web interface for FreeRADIUS. > > Eventually I'd like to bring the execution of a few system commands > (executing mysql binary and importing an SQL file into it) into Perl, > however, for now I just need it to work.
Well, that's pragmatic. :-) But it's generally the best way: Find the answer first, improve upon it second. > Essentially I don't have the time to rewrite that entire portion right > now, so I'd like to know the best way to execute the SQL system commands > and be 100% sure that it ran properly, and if not, I would be notified. There are few things that are 100% certain. But let's see what we can do. > At this point, the command is done via backticks. > > What I'd like to know is what would be the best way to quickly hack this > so that if it fails and neglects to insert every row, I could have the > app tell me (via email or whatever) so I don't have to do a manual check > every morning. > > AFAICT, I've got the backtick option, system or eval. You don't mean eval. You think you mean exec, but you don't mean that either, probably. > Will system or eval be able to see that each row is inserted without > error when the mysql binary is called at system level? Or would it be > best if I just took the time now and did it with DBI immediately instead? I think you're looking for the program's exit status. Traditionally on Unix and many similar systems, the exit status is an integer, with 0 meaning "normal exit" and anything else meaning that something went wrong. That's the value that's used by programs that run other programs (such as the 'make' system utility) and need to know when a step has failed. In Perl, you can access the exit status with the $? variable after running a command via system or backticks. Beware: If your command is run by the shell, you'll get the shell's exit status, which may not be the exit status you were looking for. You can also consider capturing the STDERR output of the external program. Since the exit status doesn't say much, most programs cough out some last words when something goes wrong. In fact, if the program outputs anything to STDERR, even if it exited with "success", the error text may be important news you'd want to treat as a failure. One common way to capture STDERR when running an external program is with IPC::Open3. I must admit to a philosophical problem with the idea of a program that sends email when something goes wrong. How, I ask myself, does such a program report that it cannot send mail? That 100% is looking more and more elusive.... Hope this helps! --Tom Phoenix Stonehenge Perl Training -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] http://learn.perl.org/
