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Deleting all but a regex using sed, tr, cut etc

 
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# 1  
Old 08-28-2011
Question Deleting all but a regex using sed, tr, cut etc
Hi guys, this is my first post, though I've been looking around the forums for a while trying to find a solution to my problem. I want to be able to take a several lines of text (an out put from get-iplayer and ls to be precise) and only keep the crazy alphanumerical code in each line. For example:

Quote:
Originally Posted by get-iplayer
b011rf7y: Doctor Who: Series 6 - 7. A Good Man Goes to War
b0146h0q: Doctor Who: Series 6 - 8. Let's Kill Hitler
and also

Quote:
Originally Posted by ls
Doctor_Who_Confidential_Series_5_-_8._After_Effects_b00sj9qj_default.flv
Doctor_Who_Series_5_-_8._The_Hungry_Earth_b00sj9sq_default.flv
Doctor_Who_Series_6_-_1._The_Impossible_Astronaut_b010tb7q_default.flv
All I want to do is extract the codes (e.g. b011rf7y, b00sj9qj), so I can compare them.

I've tried using Sed, tr, and cut but I can't seem to get the right output (though I can do plenty of other neat things). Which of these should I be using? I think my regex is
Code:
'((?:[a-z][a-z]*[0-9]+[a-z0-9]*))'

but I'm not sure (from txt2re.com by the way)
# 2  
Old 08-28-2011
Code:
[ZSH-4.3.11] tmp % cat testlist
b011rf7y: Doctor Who: Series 6 - 7. A Good Man Goes to War
b0146h0q: Doctor Who: Series 6 - 8. Let's Kill Hitler
Doctor_Who_Confidential_Series_5_-_8._After_Effects_b00sj9qj_default.flv
Doctor_Who_Series_5_-_8._The_Hungry_Earth_b00sj9sq_default.flv
Doctor_Who_Series_6_-_1._The_Impossible_Astronaut_b010tb7q_default.flv


[ZSH-4.3.11] tmp % cut -d : -f 1 -s  testlist 
b011rf7y
b0146h0q


[ZSH-4.3.11] tmp % cut -d : -f 2-3  testlist  
 Doctor Who: Series 6 - 7. A Good Man Goes to War
 Doctor Who: Series 6 - 8. Let's Kill Hitler
Doctor_Who_Confidential_Series_5_-_8._After_Effects_b00sj9qj_default.flv
Doctor_Who_Series_5_-_8._The_Hungry_Earth_b00sj9sq_default.flv
Doctor_Who_Series_6_-_1._The_Impossible_Astronaut_b010tb7q_default.flv

#OR

[ZSH-4.3.11] tmp % cut -d : -f 2-3  testlist | sed 's/^ //g; s/://g; s/ /_/g'
Doctor_Who_Series_6_-_7._A_Good_Man_Goes_to_War
Doctor_Who_Series_6_-_8._Let's_Kill_Hitler
Doctor_Who_Confidential_Series_5_-_8._After_Effects_b00sj9qj_default.flv
Doctor_Who_Series_5_-_8._The_Hungry_Earth_b00sj9sq_default.flv
Doctor_Who_Series_6_-_1._The_Impossible_Astronaut_b010tb7q_default.flv

Last edited by xbin; 08-28-2011 at 11:40 AM..
# 3  
Old 08-28-2011
Maybe this would be enough (GNU grep):
Code:
egrep  -o 'b[0-9a-z]{7}'

# 4  
Old 08-28-2011
Thanks Yazu I'll give it a go, I think I can see whats happening.

Xbin, really struggling to see what you've done...Smilie
# 5  
Old 08-28-2011
So does it works for you or not?
Code:
$ cat >INPUTFILE
b011rf7y: Doctor Who: Series 6 - 7. A Good Man Goes to War
b0146h0q: Doctor Who: Series 6 - 8. Let's Kill Hitler
Doctor_Who_Confidential_Series_5_-_8._After_Effects_b00sj9qj_default.flv
Doctor_Who_Series_5_-_8._The_Hungry_Earth_b00sj9sq_default.flv
Doctor_Who_Series_6_-_1._The_Impossible_Astronaut_b010tb7q_default.flv

$  egrep  -o 'b[0-9a-z]{7}' INPUTFILE 
b011rf7y
b0146h0q
b00sj9qj
b00sj9sq
b010tb7q

===

O, yes. I didn't understand about struggling... Ok, it's not for me. Smilie
This User Gave Thanks to yazu For This Post:
Pureferret
# 6  
Old 08-28-2011
Yazu, It works perfectly! thanks very much!

---------- Post updated at 06:47 PM ---------- Previous update was at 05:44 PM ----------

Ok the egrep line works, but I'd like it to change the file I act it on, not just print out to the terminal.

Code:
egrep  -o 'b[0-9a-z]{7}' ./FILENAME > ./FILENAME

That just wipes all lines from the file. I can't see anything salient in the man file either.

Advice?
# 7  
Old 08-28-2011
Just output it in another file.
Code:
egrep  -o 'b[0-9a-z]{7}' FILENAME >FILENAME.codes

And then, if you want
Code:
rm FILENAME
mv FILENAME.codes FILENAME

It's possible to do it in one step with sed or perl, but it's not safe.
 
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