Hi,
I usually use rev twice, e.g.
echo blablabla_bla_p123_default.mp3|rev|cut -f2 -d'_'|rev
HTH, Willem
On Wed, 29 Jul 2015, Tony Baechler wrote:
Hi all,
The recent discussion on shell scripts got me thinking. A couple of posters
invited people to post problems they're having with scripts to the list, so
here goes.
I have not actually written a script for this because I'm not sure how to go
about it. I would normally use cut, but I need to cut from right to left.
The cut help doesn't indicate a way to do this. You can only cut from the
beginning of the line or a range of bytes. The problem is each line
(filenames, to be exact) are of different lengths, so it's impossible to know
what range of bytes I need.
What I'm trying to do is extract the BBC PID from the downloaded files. It's
a lower case alphanumeric string which starts with a letter and is eight
characters. In my case, the first letter is always "b" or "p," so if I could
use something like grep to just extract the first lower case letter followed
by a number up to the next underscore, that would be good. I don't think
grep will just print a matching phrase, only the matching line. Here are
some example filenames:
5_live_Science_-_Coding_and_Computers_b062dj5j_default.mp3
Witness_-_The_Sinking_of_the_USS_Indianapolis_p02wdykn_default.mp3
Discovery_-_A_Scientific_View_of_Agriculture_p0053gbd_default.mp3
Click_-_05_10_2010_p00b18gp_default.mp3
As you can see, they all follow a similar format. If I could go from right
to left, I would simply cut "_default.mp3" and extract the preceeding 8
bytes, but I can't figure out how. What I'm trying to do is first extract
the PIDs, hopefully preserving the filenames in the process. Once they are
extracted (or printed to stdout), I want to use wget to download the BBC
programme page. If you go to www.bbc.co.uk/programme/bXXXXXXX, you'll get a
web page displaying the broadcast date, description and notes. I would like
to download those pages.
Any help with this would be greatly appreciated. Thanks in advance.
--------------------
Tony Baechler, Baechler Access Technology Services
Putting accessibility at the forefront of technology
mailto:bats@xxxxxxxxxxxxxx
Phone: 1-619-746-8310 Fax: 1-619-449-9898
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