bash wildcard n digits

Question

So I\'ve got the following files in the tmp directory:

 file.0
 file.1
 file.t9
 file.22
 file.4444

if I wanted to list only the files that

Answer 1

You can use ls just to list all the files then filter the output of that through grep:

ls -1 | grep -E '\.[0-9]+$'

as per the following test:

pax> printf 'file.0\nfile.1\nfile.t9\nfile.22\nfile.4444\n' | grep -E '\.[0-9]+$'
file.0
file.1
file.22
file.4444

The -E gives you extended regular expressions so that the + modifier works. If that's not available to you, you can use the \.[0-9][0-9]*$ regex instead.

Answer 2

Another simple solution to just prevent seeing (ie hide) "ugly errors" is to redirect standard error to /dev/null by appending 2> /dev/null. In your example:

ls tmp/file.{[0-9],[0-9][0-9],[0-9][0-9][0-9],[0-9][0-9][0-9][0-9]} 2> /dev/null

This would give you the results you want and hide any errors. Works with any linux command or executable that sends output to stdout and errors to stderr. Note that this does not affect the command return status ($?), it just suppresses errors.

Answer 3

Another variant for filtering files of a specific extension is to use the find command with a set of predicates:

find tmp/ -type f -iregex '^.*\.[0-9]+$'

The -type predicate matches only files and the -iregex matches names that end with one or more digits - ignoring case of the name. If you want to filter files that begin with file you would use the following instead:

find tmp/ -type f -iregex '^.*/file\.[0-9]+$'

And finally, if you don't want the whole path displayed for each resulting file, use the following:

find tmp/ -type f -iregex '^.*/file\.[0-9]+$' -printf "%f\n"

Answer 4

At least in bash 4, when the extglob shell option is enabled:

shopt -s extglob
ls /tmp/file.+([0-9])

The pattern +([0-9]) there matches one or more digits.

You can read more about this in the Pattern Matching section of man bash.

UPDATE

Actually, as @chepner pointed out, since extglob was introduced in version 2.02, this should work in pretty much every bash you come across today, unless you pulled your distro out of a rock or something.