Jim Gibson <jimsgib...@gmail.com> writes: > On Jun 11, 2013, at 9:44 PM, lee wrote: >> I've been googling for examples of how to create a sha-2 sum of a >> file in perl without success. What I'm looking for is something >> like: >> >> $hash = create_sha2_sum( $filename); >> >> Do you know of any examples I could look at? Or is there a better >> way to figure out if a file has been modified? > > The first thing to do would be to check the file size. If the file > size has changed, then the file has been modified. So you will want to > save the file size.
The file might be modified without changing its size ... > If the files sizes are the same, then you can compare some sort of > digest e.g. SHA. I haven't used any, so I cannot advise. ... so I'm better off by just using a hash which I'd need anyway. > A good place to look for Perl modules is the Comprehensive Perl > Archive Network (CPAN). Go to http://search.cpan.org and enter SHA > into the search box. This will give you modules such as Digest::SHA, > which seems to do what you want. > > Next, install the module on your system. On a Unix-like system or one > that supports command-line input, you would do: > > cpan install Digest::CPAN > > The first time you run cpan, it will need to configure your > environment. You may have to use 'sudo cpan' for the first command. The problem is that I don't know how to use this Digest thing, and I don't know perl well enough to understand the description. I was hoping I could learn from some example that uses it. -- "Object-oriented programming languages aren't completely convinced that you should be allowed to do anything with functions." http://www.joelonsoftware.com/items/2006/08/01.html -- To unsubscribe, e-mail: beginners-unsubscr...@perl.org For additional commands, e-mail: beginners-h...@perl.org http://learn.perl.org/
