Use sed to find whole word and replace I have the following block of text in a file: test3.legacy test4.legacy test3 test3.kami I only want to search for `test3` as a whole and replace it with nothing. Unfortunately, all my attempts have removed **test3** from `test3.legacy` and `test3.kami`. I've tried: sed 's/^test3://g' myfile.txt sed 's/\btest3\b//g' myfile.txt sed 's/\<test3\>//g' myfile.txt without any luck. Any ideas how I can resolve this please? **EDIT:** Most attempts have resulted in the following: `.legacy test4.legacy .kami`

Is this what you want?


$ sed 's/\(^\| \)test3\( \|$\)/\1/g' file
test3.legacy test4.legacy test3.kami


This say


substitute
(^ start of line OR space)
test3
(space OR end of line)
with match 1 (AKA space or start of line)


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**_Update:_**

And as so elegantly put by the good @Stephane Chazelas this would not take care of certain cases. Also emphasize on the portability part. See answer below.

A GNU variant could, _(hopefully)_ , be:


sed 's/\(^\| \)\(test3\( \|$\)\)*/\1/g'
# Or perhaps:
sed 's/\(^\| \)\(test3\( \|$\)\)\+/\1/g'


taking care of repetitive matches. Optionally one would take care of multiple spaces etc as well. Depending on input.

EOUPD

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As an alternative perhaps ( _only meant as a starting point_ ):


sed 's/\Wtest3\W/ /g'


Not this I assume:


$ sed 's/test3\.\?[^ ]* *//g' file
test4.legacy