Bash string replace

limmer · #1 (**permalink**) 5 Days Ago

Bash shell. I'm trying to filter a string taken from user input. I can replace one word at a time. This method supports regex, so is it possible to replace various words at a time?

Code:

STRING="Hello World! word1 word2";

FILTERED=${STRING/word1|word2/}; # Not working: replace 2 or more words ???

echo $FILTERED;

Scrutinizer · #2 (**permalink**) 5 Days Ago

Parameter expansion uses shell pattern matching, not regex.
You could use e.g. to filter out either or both words and the space before it.

Code:

FILTERED=${STRING//@( word1| word2)/}

You need to use a double slash otherwise it will just match one word in case there are two matching words.

or, if you do not seek to filter out these specific words, just plain:

Code:

FILTERED=${STRING% * *}

limmer · #3 (**permalink**) 5 Days Ago

I tried this code but is not functional (at least in bash). FILTERED still outputs the string unchanged. The second code posted does work though.

FILTERED=${STRING//@( word1| word2)/}

Scrutinizer · #4 (**permalink**) 5 Days Ago

Does this work?

bash code:

Code:

shopt -s extglob
STRING="Hello World! word1 word2"
FILTERED=${STRING//@( word1| word2)/}
echo $FILTERED

---------- Post updated at 12:55 PM ---------- Previous update was at 12:28 PM ----------

This should work too:

Code:

FILTERED=${STRING/+( word1| word2)}

limmer · #5 (**permalink**) 5 Days Ago

Yes, shopt was missing.

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