Is there a simpler way to write:
wc -l foo?.txt foo??.txt ?
Since in my case I have (at most) two digit numbers, I tried using the range specification wc -l foo[1-99].txt but this ended up displaying only results between 1 and 9 (instead of 99). But this is a (nonworking) hack, and I really need something like wc -l foo[?,??].txt.
When you have two or more choices, use brace expansion:
foo{?,??}.txt
Or, to be more specific:
foo{[0-9],[0-9][0-9]}.txt
Let's consider a directory with these three files:
$ ls foo*txt
foo111.txt foo11.txt foo1.txt
Observe:
$ echo foo{?,??}.txt
foo1.txt foo11.txt
And:
$ echo foo{[0-9],[0-9][0-9]}.txt
foo1.txt foo11.txt
Or, more concisely:
$ echo foo{,[0-9]}[0-9].txt
foo1.txt foo111.txt
With bash's extended glob (extglob) syntax, you can use foo@(?|??) e.g.
wc -l foo@(?|??).txt
The extglob option should be enabled by default in the interactive shell on current Ubuntu releases, but if not you can enable it using
shopt -s extglob
