Wildcard expansion - searching for one in a set of possibilities

Question

Hi all,

I could have sworn you could do the following:

ls *.{java, cpp}

but that does not seem to work. I know this answer is probably on the site somewhere but I couldn't find it via search.

For instance, if I want to be able to use the globbing with a find command, I would want to do something like

find . -name "*.{java,cpp}" | xargs grep -n 'TODO'

Is this possible without resorting to using the -o binary operator?

Answer 1

But this does work in Bash:

$ ls
a.h  a.s  main.cpp  main.s
$ ls *.{cpp,h}
a.h  main.cpp

Are you sure you're in Bash? If you are, maybe an alias is causing the issue: try /bin/ls *.{java,cpp} to make sure you don't call the aliased ls.

Or, just take out the spaces in your list inside the {} -- the space will cause an error because Bash will see *.{java, as one argument to ls, and it will see cpp} as a second argument.

Answer 2

ls *.{java,cpp} works just fine for me in bash...:

$ ls *.{java,cpp}
a.cpp    ope.cpp  sc.cpp  weso.cpp
helo.java   qtt.cpp  srcs.cpp

Are you sure it's not working for you...?

find is different, but

find -E . -regex '.*\.(java|cpp)'

should do what you want (in some versions you may not need the -E or you may need a -regextype option there instead, "man find" on your specific system to find out).

Answer 3

It is likely that you are seeing an error message such as this:

ls: cannot access *.{java: No such file or directory
ls: cannot access ,cpp}: No such file or directory

If that's the case, it's because of the space after the comma. Leave it out:

ls *.{java,cpp}

For future reference, it is more helpful to post error messages than to say "it's not working" (please don't take this personally. It's meant for everyone to see. I even do it sometimestoo often).

Answer 4

For your particular example, this may also do what you want

grep -rn TODO . --include '*.java' --include '*.cpp'