Shell – List files in a directory with a certain extension

shellwildcards

I created a file called ~/usrlibs.txt, which contains the number of files that begin with lib and end .a found in the /usr/lib directory.

I tried:

ls -l /usr/lib/lib .a | wc -w > ~/usrlibs.txt

But this command is not working correctly.

What am I missing?

Do you mean list all files that start with lib and end with .a in /usr/lib, then print the wordcount with wc to usrlibs.txt?

ls -l /usr/lib/lib*.a | wc -w > ~/usrlibs.txt

should work. You just forgot to add a wildcard between your patterns.

In zsh, you can use a recursive glob:

mkdir ~/epubs
mv -- **/*.epub ~/epubs/

In bash ≥4, run shopt -s globstar (you can put this in your ~/.bashrc) then the command above. In ksh, run set -o globstar first.

With only POSIX tools, run find:

find . -name '*.epub' -exec mv {} ~/epubs \;

Brace expansion will get the job done. man bash and search for Brace Expansion.

cp *.{txt,jpg,png} destination/

EDIT:

In keeping with the OP's request, the command above was missing the verbose option:

cp -v *.{txt,jpg,png} destination/