Problem with occurence of square brackets


 
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# 1  
Old 06-11-2014
Problem with occurence of square brackets

Hello all,

I have the following problem:

Code:
$ cat infile
this is spam [i need this] and i need this too
this is spam [i need this][this is spam] and i need this too
$ perl -nwe '$_ =~ /[^\]]+ \[([^\]]+)\]\[?[^\]]*\]? ([^\]\[]+)$/; print "$1 - $2\n";' infile
i need this - too
i need this - and i need this too

I am not sure how many occurences of these square brackets will show up, at the moment I assume it is 1 for sure, maybe 2, but I always need the 1st and the complete text behind the last closing square bracket. As you can see for the 1st line, this doesn't work.

Any hints are welcome, thanks a lot.
# 2  
Old 06-11-2014
I'm not familiar with perl regex, but you could do it it sed by using 2 substitutions:
Code:
$ cat ~/tmp/file.txt
this is spam [i need this] and i need this too
this is spam [i need this][but not this] and i need this too
this is spam [i need this][but not this] [or this ] and i need this too
$  sed 's/^[^[]*\[\([^]]*\)\]/\1/g; s/\[[^]]*\]//g' ~/tmp/file.txt
i need this and i need this too
i need this and i need this too
i need this  and i need this too

This User Gave Thanks to CarloM For This Post:
# 3  
Old 06-11-2014
I couldn't do it in regex...

Code:
$ awk -F'[][]' '{print $2,$NF}' infile
i need this  and i need this too
i need this  and i need this too

# 4  
Old 06-11-2014
Thanks a lot guys.

@neutronscott:
Because it needs to be run on different platforms which includes Windows, I will have to use Perl - so I can't use awk, sorry I missed to point this out.

@CarloM:
I am curious if I can solve it in one expression. Maybe other gods of RegExp shed some light Smilie I am stuck at the moment. If there is no other way, I will use the 2 separate statements.
# 5  
Old 06-11-2014
Code:
$ sed 's/[^[]*[[]\([^]]*\)]\([[][^]]*]\)*\([^]]*\)$/\1 -- \3/g' infile
i need this --  and i need this too
i need this --  and i need this too

?
This User Gave Thanks to neutronscott For This Post:
# 6  
Old 06-11-2014
May be split can help?

Code:
perl -nwe '@a=split(/\[|\]/,$_); print "$a[1] - $a[$#a]\n";' infile
i need this -  and i need this too

i need this -  and i need this too

i need this -  and i need this too



infile
Code:
this is spam [i need this] and i need this too
this is spam [i need this][this is spam] and i need this too
this is spam [i need this][this is spam][this is spam too] and i need this too

This User Gave Thanks to clx For This Post:
# 7  
Old 06-11-2014
Thanks for the answers, guys.
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