Shell Programming and Scripting

Hi There!

I'm stuck with a problem trying to output some sections of a rss feed to my conky program using curl and sed.

The rss feed is for tide times and I wish to output the times but not the rest to the conky desktop. To do this I need to pull out the four instances of times that are in the format of '00:00'. Since the digits will vary I have to match the sequence of two digits followed by a colon followed by two digits. This is what I tried so far:

Code:

#RSS Setup
URI=http://www.tidetimes.org.uk/southampton-tide-times.rss #URI of RSS Feed
LINES=1 #Number of headlines

#Environment Setup
EXEC="/usr/local/bin/curl -s" #Path to curl
TODAY=`date +%Y%m%d`
#Work Start
$EXEC $URI | grep description |\
sed -e 's/\([0-9]{2}:[0-9]{2}\)*/(&)/'

I have to admit my knowledge of sed is a bit shaky and the above has outputted a lot of gibberish. Any suggestions as to how I might pull out the four instances of the tide times in the format '00:00'?

Hmmm, thanks for that. It partially works - it pulls out the last time in the sequence but not the three times before. Sounds like it's going in the right direction though...

One solution using Perl:

Code:

$
$ curl -s http://www.tidetimes.org.uk/southampton-tide-times.rss | grep description | perl -lne 'print $1 while (/(\d\d:\d\d)/g)'
03:16
09:15
15:44
21:43
$
$

Or if you want it to be a bit more descriptive:

Code:

$
$ curl -s http://www.tidetimes.org.uk/southampton-tide-times.rss | grep description | perl -lne 'print $1 while (/(\d\d:\d\d.*?)&/g)'
03:16 - High Tide
09:15 - Low Tide
15:44 - High Tide
21:43 - Low Tide
$
$

Ok thanks durden_tyler I forgot about the power of perl - it is a more elegant solution. That said the sed thing will still bother me for a bit.

Also I've realised I need to do a bit more work yet. In order to present the data in conky more flexibly I have realised that I need to execute the script in conky for each instance of tide time - that is separately. I suspect I will need to create a variable that can be passed from each of the lines in conky to the script which will have a perl loop that loops to the specific instance of tide time based on the passed variable. Looks like a bit of mugging up on perl may be required! Thanks again.

---------- Post updated at 10:26 AM ---------- Previous update was at 08:32 AM ----------

I'm a dunderhead. I can use tail and head to output the specific line of course. Problem solved.

Thanks again for the help.