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Cut out string in bash script

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# 1  
Old 02-21-2010
Cut out string in bash script
Hi all,
I'm trying to extract string from variable in BASH. That's probably trivial for grep but I couldn't figure it out.

I want to get name, there's sometimes digit after it, but it should be left out.
Code:
STRING=http://name5.domain.com:8000/file.dat

Could someone help me with that?
Any solution will do. Smilie
# 2  
Old 02-21-2010
The following works fine if there's always a digit after "name" and none embedded within it.

Code:
$ STRING=http://name5.domain.com:8000/file.dat
$ n=${STRING%%[0-9]*}
$ n=${n#*//}
$ echo $n
name

Last edited by alister; 02-21-2010 at 07:15 PM..
# 3  
Old 02-21-2010
Code:
$ 
$ STRING=http://name5.domain.com:8000/file.dat
$ 
$ echo $STRING | perl -lne '/http:\/\/(.*?)\d.*/ && print $1'
name
$ 
$

tyler_durden
# 4  
Old 02-21-2010
The following will extract the first component of the url and strip any trailing digits that may be present (leading or embedded numbers are left intact):

Code:
echo "$STRING" | awk -F'\\/\\/|\\.' '{sub(/[0-9]+$/, "", $2); print $2}'


@durden tyler
Quote:
Originally Posted by durden_tyler
Code:
$ 
$ STRING=http://name5.domain.com:8000/file.dat
$ 
$ echo $STRING | perl -lne '/http:\/\/(.*?)\d.*/ && print $1'
name
$ 
$

That perl will not work if the trailing digit is not present or if there's a digit embedded elsewhere in the name. The latter may be unlikely, but the original query states that the digit is not always present.

Cheers,
Alister
# 5  
Old 02-21-2010
Thanks guys for fast response!

Maybe I wasn't clear enough about that digit, but yeah, alister's solution works in both cases.

Cheers.
# 6  
Old 02-21-2010
One more Smilie

Code:
echo $STRING | sed 's|^http://\([^.]*\)\..*$|\1|; s|[0-9]*$||'

Alister
# 7  
Old 02-21-2010
Quote:
Originally Posted by alister
...
That perl will not work if the trailing digit is not present or if there's a digit embedded elsewhere in the name. The latter may be unlikely, but the original query states that the digit is not always present.
...
Sorry, my bad.

Here's a file that contains variations of the URL, with the digit at the end, at the beginning, in between, and non-existent.

Code:
$ 
$ cat -n f6
     1  http://name5.domain.com:8000/file.dat
     2  http://na5me.domain.com:8000/file.dat
     3  http://5name.domain.com:8000/file.dat
     4  http://name.domain.com:8000/file.dat
$ 
$

Here's the Perl equivalent of your second awk script i.e. remove digit at the end (if present), but retain digit in-between or at the beginning (if present). Otherwise just fetch the word between "//" and "." that does not have any digits.

Code:
$ 
$ perl -lne '/http:\/\/(.*?)(\d)*\..*/ && print $_,"\t=>\t",$1' f6
http://name5.domain.com:8000/file.dat   =>      name
http://na5me.domain.com:8000/file.dat   =>      na5me
http://5name.domain.com:8000/file.dat   =>      5name
http://name.domain.com:8000/file.dat    =>      name
$ 
$

Since nothing has been mentioned about the case when the digit is at the beginning or in-between, I shall consider a couple of cases.

Case 1:
The digit at the beginning is to be removed.
The digit in-between has to be retained.
The digit at the end is to be removed.
Which means - "remove digits from the ends, retain it in the middle".

Code:
$ 
$ perl -lne '/http:\/\/(\d)*(.*?)(\d)*\..*/ && print $_,"\t=>\t",$2' f6
http://name5.domain.com:8000/file.dat   =>      name
http://na5me.domain.com:8000/file.dat   =>      na5me
http://5name.domain.com:8000/file.dat   =>      name
http://name.domain.com:8000/file.dat    =>      name
$

Case 2:
The digit at the beginning is to be removed.
The digit in-between has to be removed.
The digit at the end is to be removed.
Which means - "remove digits from the ends and the middle".

Code:
$ 
$ perl -lne 'if (/http:\/\/(\d)*(.*?)(\d)*\..*/){ ($x = $2) =~ s/\d//g; print $_,"\t=>\t",$x}' f6
http://name5.domain.com:8000/file.dat   =>      name
http://na5me.domain.com:8000/file.dat   =>      name
http://5name.domain.com:8000/file.dat   =>      name
http://name.domain.com:8000/file.dat    =>      name
$

tyler_durden
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