Cat files except one [duplicate]

Question

This question already has an answer here:

• Remove all files/directories except for one file 7 answers

I'm looking for something to concatenate all files with given extension within a directory, except one. Like:

cat *.txt !(DISCARD.txt)  > catKEPT

This should concatenate all *.txt files in directory, except DISCARD.txt.

Answer 1

find . -maxdepth 1 -iname '*.txt' -not -name 'DISCARD.txt' -exec cat {} +>catKEPT

Answer 2

If you are using bash (most of the time this is the case), you may use the extglob shell option that will extend your shell with a more powerful pattern matching syntax.

You can turn it on with shopt -s extglob, and turn it off with shopt -u extglob.

In your example, you would simply do:

$ shopt -s extglob
$ cat -- !(DISCARD).txt > catKEPT

You can find more about this command in this StackOverflow answer.