UNIX for Dummies Questions & Answers

Thanks for the all the help last evening on CRON jobs. It's now working.

Is it possible with cron to save a backup of a file to a different server or location? The idea being that if one host goes arse over tit, I'll have a backup of the DB on another server?

Many thanks,
Ed Ludlow

Well ... this does not have anything to do with cron itself. cron is a timer daemon running in the background to run certain tasks specified at regular intervals. It does not really care what is being executed. Simply invoke a command or write a simple script which transfers the file to a remote location, and have cron runs it as usual. If you have multiple commands to execute in each iteration, writing a wrapper shell script allows you to include arbitrarily complicated logic in it.

There are a number of ways to transfer a file, depending on what server is available on your machine. I have used cron to regularly transfer backups with scp(1), also with a simple Perl script using the Net::FTP module, both invoked through a wrapper shell script which is executed by cron. Either way, that's still quite easy.

Thanks for the reply!

I'm a total newbie to Unix, so is there a script available on the web I could download, and adapt a little?

Can CRON run any form of script? I could for example code something in PHP telling it to transfer?

Thanks,
Ed

Yes, cron can run anything that can be executed on the command line. I am pretty sure if you have PHP installed as a command-line executable (rather than just an Apache handler which only contains a shared library) cron will be able to run a PHP script, although I don't know PHP myself. I use only Perl.

By the way, my Perl FTP script looks like the following:

Code:

#!/usr/bin/perl -w

# Transfer specified file with FTP

use Net::FTP;

my $ftp = Net::FTP->new('host.domain.com', Debug => 0);
$ftp->login("user", "password@host");
$ftp->cwd("/Documents/somewhere");
$ftp->put('manual.pdf');
$ftp->quit();

0;

There are also some related threads on this forum (some in FAQ) on automated file transfer. You may also search for them and see if you get any useful hints.