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non alpha characters in sed + making it fast?

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# 1  
Old 10-01-2010
non alpha characters in sed + making it fast?
hello, I'm trying to write the fastest sed command possible (large files will be processed) to replace RICH with NICK in a file which looks like this (below) if the occurance of RICH is uppercase, replace with uppercase if it's lowercase, replace with lowercase

SOMTHING_RICH_SOMTHING <- replace here
hellorichwhatareyoudoing <- do not replace here, forms part of a word
SOMTHING.RICH.SOMTHING <- replace here
somthing_rich_somthing <- replace here
HELLO-RICH-HELLO <- replace here

I've used the find operator first to speed up execution how do I alter the sed to achieve the above requirements?

Code:
sed '/RICH/ s/RICH/NICK/g' filename   # executes more quickly

# 2  
Old 10-01-2010
hi,
try this:
Code:
s/\(.*[_.-]\)\([Rr][iI][Cc][Hh]\)\([_.-].*\)/\1NICK\3/g

i got the following output for your input:
Code:
SOMTHING_NICK_SOMTHING 
hellorichwhatareyoudoing 
SOMTHING.NICK.SOMTHING 
somthing_NICK_somthing 
HELLO-NICK-HELLO

use this simple one:
Code:
s/\(.*[_.-]\)\(rich\)\([_.-].*\)/\1NICK\3/ig

i - ignore case sensitive (forgot this Smilie )

with the first approach below words will be considered:
Code:
RIch
RicH etc

Last edited by dragon.1431; 10-01-2010 at 01:27 PM.. Reason: added more accurate solution
# 3  
Old 10-01-2010
Quote:
Originally Posted by dragon.1431
hi,
try this:
Code:
s/\(.*[_.-]\)\([Rr][iI][Cc][Hh]\)\([_.-].*\)/\1NICK\3/g

i got the following output for your input:
Code:
SOMTHING_NICK_SOMTHING 
hellorichwhatareyoudoing 
SOMTHING.NICK.SOMTHING 
somthing_NICK_somthing 
HELLO-NICK-HELLO

not quite what I was expecting Smilie, My fault probably for not being clear enough with the requirement:

Code:
richard@opensolaris:~/share/cleaner$ echo "RICH_SOMTHING" | sed 's/\(.*[_.-]\)\([Rr][iI][Cc][Hh]\)\([_.-].*\)/\1NICK\3/g'
RICH_SOMTHING

richard@opensolaris:~/share/cleaner$ echo "SOMTHING@RICH" | sed 's/\(.*[_.-]\)\([Rr][iI][Cc][Hh]\)\([_.-].*\)/\1NICK\3/g'
SOMTHING@RICH



---------- Post updated at 05:48 PM ---------- Previous update was at 05:29 PM ----------

basically it's a case of "if there are any letters (with no spaces) directly to the left or right of the string I'm replacing, don't replace it" so the following must be left alone:

HELLORICHHELLO
HELLORICH
RICHHELLO

anything other than the above is fair game Smilie with the added condition that 'if you're doing a replace and the string being replaced is lower case, replace with lowercase, if uppercase, replace with uppercase Smilie

---------- Post updated at 06:11 PM ---------- Previous update was at 05:48 PM ----------

Nearly got it...

Code:
richard@opensolaris:~/share/cleaner$ echo "@rich" | sed 's/\(.*[_.-.@]\)\(rich\)\([_.-.@].*\)/\1NICK\3/ig'
@rich
richard@opensolaris:~/share/cleaner$ echo "@RICH@" | sed 's/\(.*[_.-.@]\)\(rich\)\([_.-.@].*\)/\1NICK\3/ig'
@NICK@

Last edited by rich@ardz; 10-01-2010 at 01:54 PM..
# 4  
Old 10-01-2010
hi,
give your exact input and output.
please note that i posted code as per your first post.
# 5  
Old 10-03-2010
input:
Code:
hellorichhello
HELLORICHHELLO
SOMTHING-RICH-SOMTHING
SOMTHING@RICH
@RICH
RICH@
-RICH
RICH-
SOMTHING_RICH_SOMTHING
_RICH
RICH_
SOMTHING RICH SOMTHING
somthing rich somthing

output:
Code:
hellorichhello
HELLORICHHELLO
SOMTHING-NICK-SOMTHING
SOMTHING@NICK
@NICK
NICK@
-NICK
NICK-
SOMTHING_NICK_SOMTHING
_NICK
NICK_
SOMTHING NICK SOMTHING
somthing NICK somthing

basically if the string to be replaced has an alphabetic character to the left or right (or left AND right) of it, don't replace it - if it has anything other than an alphabetic char (inc. spaces) to the left or right of it (or left AND RIGHT), replace it...
Last edited by Scott; 10-03-2010 at 07:23 AM.. Reason: Code tags
# 6  
Old 10-03-2010
Code:
sed 's/\(^\|[^[:alnum:]]\)\(rich\|RICH\|Rich\)\([^[:alnum:]]\|$\)/\1NICK\3/g' infile

This User Gave Thanks to Scrutinizer For This Post:
rich@ardz
# 7  
Old 10-05-2010
Quote:
Originally Posted by Scrutinizer
Code:
sed 's/\(^\|[^[:alnum:]]\)\(rich\|RICH\|Rich\)\([^[:alnum:]]\|$\)/\1NICK\3/g' infile

Smilie I won't even pretend i understand how this sed works! but it does! is it possible to replace uppercase with uppercase and lower with lower or would i have to run 2 different seds... cheers Smilie
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