Regex:search/replace but not for escaped character


 
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# 1  
Old 10-18-2012
Regex:search/replace but not for escaped character

Hi

Input:
Code:
-
--
---
----
aa-bb-cc
aa--bb--cc
aa---bb---cc
aa----bb----cc

Output:
Code:
.
-
-.
--
aa.bb.cc
aa-bb-cc
aa-.bb-.cc
aa--bb--cc

I need to replace a simple '-' with '.' but if I want to keep the '-' I will use '--'

I would a like a solution where regex is used as search criteria and the match will be replace with a value. A solution that can be used in language.

Thx in advance
# 2  
Old 10-18-2012
This is a three step process:
  1. Convert all occurrences of -- to something that doesn't appear in your input.
  2. Convert all remaining occurrences of - to ..
  3. Convert all of the characters you converted to in step 1 back to -.
The way you do this "in language" depends on what language you want to use.
This User Gave Thanks to Don Cragun For This Post:
# 3  
Old 10-18-2012
Here is how Don Cragun suggested using sed

Code:
sed 's/\-\-/\%/g' | sed 's/\-/\./g' | sed 's/\%/\-/g'

# 4  
Old 10-18-2012
Great solution. Thx
# 5  
Old 10-18-2012
Quote:
Originally Posted by bipinajith
Here is how Don Cragun suggested using sed

Code:
sed 's/\-\-/\%/g' | sed 's/\-/\./g' | sed 's/\%/\-/g'

Yes; or more succinctly in sed:
Code:
sed -e 's/\-\-/\%/g' -e 's/\-/\./g' -e 's/\%/\-/g'

or even
Code:
sed 's/\-\-/\%/g;s/\-/\./g;s/\%/\-/g'

or in awk:
Code:
awk '{gsub(/--/,"%");gsub(/-/,".");gsub(/%/,"-");print}'

but there are LOTS of languages. Why don't we let the submitter tell us what language he wants.
# 6  
Old 10-18-2012
Quote:
Originally Posted by bipinajith
Code:
sed 's/\-\-/\%/g' | sed 's/\-/\./g' | sed 's/\%/\-/g'

Quote:
Originally Posted by Don Cragun
Yes; or more succinctly in sed:
Code:
sed 's/\-\-/\%/g;s/\-/\./g;s/\%/\-/g'

That's a lot of unnecessary and undefined escape sequences (which are typically treated by pretending the backslash wasn't there):
Code:
sed 's/--/%/g; s/-/./g; s/%/-/g'

Regards,
Alister
This User Gave Thanks to alister For This Post:
# 7  
Old 10-18-2012
Yes, absolutely. I copied from the wrong place when I created my last post. Thank you alister for pointing out my mistake.

- Don
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