Shell Programming and Scripting

I have output like the following:

B D 20070116095820001 N D S0000579.LOG S0000582.LOG
B D 20070116095750001 N D S0000574.LOG S0000576.LOG
B D 20070116095734001 N D S0000570.LOG S0000573.LOG
B D 20070116095705001 N D S0000569.LOG S0000569.LOG
B D 20070116095644001 N D S0000566.LOG S0000567.LOG
B D 20070116095556001 N D S0000563.LOG S0000566.LOG
B D 20070116095516001 N D S0000562.LOG S0000562.LOG
B D 20070116095313001 N D S0000562.LOG
B D 20070116094213001 N D S0000562.LOG
B D 20070116094018001 N D S0000559.LOG
B D 20070116093927001 N D S0000553.LOG S0000553.LOG
B D 20061219112717001 F D S0000000.LOG S0000000.LOG

and I need to grab the 5th occurance of *.LOG (S0000570.LOG). The catch is that the number preceeding the .LOG string will change and the entire line is actually one word (verified this by trying to search for just the word S0000570.LOG using grep -w S0000570.LOG and I got the entire line back). The consistant thing is that the *.LOG string i need will always be 11 characters (such as S0000570.LOG). Can I do this with SED?

*edit* grammer

I found this browsing around that will somewhat do:

sed "s/.*\(S[0-9][0-9][0-9][0-9][0-9][0-9][0-9].LOG\).*/\1/" file

what it gives me is a list that looks like this:

S0000582.LOG
S0000576.LOG
S0000573.LOG
S0000569.LOG
S0000567.LOG
S0000566.LOG
S0000562.LOG
S0000562.LOG
S0000562.LOG
S0000559.LOG
S0000553.LOG
S0000000.LOG

While thats not exactly what I want, I believe I can pull out the 4th line, which will tell me what I need. Any one know of a better way to do this?

An awk solution:

awk 'NR==5{print $NF RS}' RS=".LOG" infile


Regards
Dimitre

Can you explain to me what that is doing? I would like to know more about awk and sed.

Sure:
- change the default input record separator (RS) to ".LOG",
so the records become:

B D 20070116095820001 N D S0000579
S0000582

B D 20070116095750001 N D S0000574
...

- match record number 5 (NR==5,
NR is the total number of input records seen so far)
and print the last field (NF is the number of fields in the current input record,
so $NF is the last field) and the record separator (RS) itself.

You have Internet


Regards
Dimitre

Wow amazing! Thanks.