Trying to remove duplicates words in a String using sed of MacOS-CodePudding

I'm trying to remove duplicates words in a string using sed from MacOS using the following command:

sed -r 's/^([A-Za-z0-9_] ) \1$/\1/' <<< 'The best of of The United Kingdom'

But it only returns

The best of of United Kingdom

What I'm missing? Could you guys give me hand? Please.

CodePudding user response：

You can try this sed

$ sed 's/\([^ ]* \)\1\ /\1/' input_file
The best of The United Kingdom

Your original code had unneeded anchors ^|$. Here is a fixed version

$ sed -r 's/([A-Za-z0-9_]* )\1 /\1/' <<< 'The best of of The United Kingdom'
The best of The United Kingdom

CodePudding user response：

I installed gnu-sed. Problem solved.

CodePudding user response：

You are unnecesarily anchoring the regex at the start and end of line. Remove ^ and $. Change -r to the POSIX -E and it will work on BSD/Mac sed. You also need the g flag to replace multiple repeating word patterns.

sed -E 's/([A-Za-z0-9_] ) \1/\1/g'