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sed - Search and replace within pattern

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# 1  
Old 08-10-2015
Scissors sed - Search and replace within pattern
Hi Guys!

Unix newbie here!

Have a requirement for which I have been scouting the forums for a solution but has been out of luck so far Smilie

I have a file which contains the following:-

Code:
TEST1|TEST2|"TEST3|1@!2"|TEST5

My sed command should result in either one the following output:-
Code:
TEST1|TEST2|TEST312|TEST5
TEST1|TEST2|"TEST312"|TEST5

The requirement is that I replace all non-alphanumeric characters within the double quotes "" with either a certain character or have that character removed.

Would really appreciate if any of you unix/sed gurus could guide me on correct path of having this sorted.

Zz
Last edited by vgersh99; 08-10-2015 at 12:01 PM.. Reason: code tags, please!
# 2  
Old 08-10-2015
something to start with:
Code:
awk -F'"' '{gsub("[^A-Za-z0-9]","",$2)}1' OFS='"' myFile

# 3  
Old 08-10-2015
Hi, try:
Code:
awk '{for(i=2; i<=NF; i+=2) gsub(/[^[:alnum:]]/,x,$i)}1' FS=\" OFS=\" file

or
Code:
awk '{for(i=2; i<=NF; i+=2) gsub(/[^[:alnum:]]/,x,$i)}1' FS=\" OFS= file

You could also try:
Code:
awk 'NR%2-1{gsub(/[^[:alnum:]]/,x)}1' RS=\" ORS= file

Last edited by Scrutinizer; 08-11-2015 at 12:22 AM..
# 4  
Old 08-10-2015
This code, inspired by the O'Reilly book "sed & awk" might help:
Code:

 # Transform quoted text to uppercase.
 /".*"/{
 h
 s/.*"\(.*\)".*/\1/
 y/abcdefghijklmnopqrstuvwxyz/ABCDEFGHIJKLMNOPQRSTUVWXYZ/
 G
 s/\(.*\)\n\(.*\)".*"\(.*\)/\2"\1"\3/
 }

By the time the code reaches the "y" command there is nothing in the pattern space other than quoted text. Replace the "y" line with your own "s" command. The last two lines recreate the whole line except for the quoted part you changed is inserted.

HTH

P.S. You might want an "s" command (instead of the "y") like
Code:
s/[^A-Z]/?/g

to replace all non (uppercase) alphabetic characters with ? or just omit the "?" to replace with nothing.
Last edited by wbport; 08-10-2015 at 05:53 PM.. Reason: Add P.S.
This User Gave Thanks to wbport For This Post:
Scrutinizer
# 5  
Old 08-11-2015
@wbport. Nice alternate approach. I think s/[^A-Z]//g should be replaced with: s/[^[:alnum:]]//g.
Also, s/\(.*\)\n\(.*\)".*"\(.*\)/\2"\1"\3/ can be simplified to s/\(.*\)\n\(.*\)".*"/\2\1/.

One caveat is that is does not work properly with multiple quoted texts on a line. For that it would need a loop with a conditional branch after that second substitution and it is easiest to achieve if the quotes are removed in the end result, so that it can work its way from back to front..
# 6  
Old 08-11-2015
Thanks loads for all your replies!! Will be trying them out and will let you know. Looking for the most simplistic/least processor intensive way of getting it done.

Regards,
Zz
# 7  
Old 08-12-2015
Code:
$ echo 'TEST1|TEST2|"TEST3|1@!2"|TEST5' | sed -e :x -e 's/"\([[:alnum:]]\{1,\}\)[^"[:alnum:]]/"\1/g; tx'
TEST1|TEST2|"TEST312"|TEST5

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