UNIX for Dummies Questions & Answers

Forgive me if this has been posted, but I could not find them.
I have thousands of files from a permutation as:

Code:

intersect-1234.tab
intersect-9914.tab
intersect-0123456.tab
intersect-9134512.tab
......

Basically there are two groups, one is the

Code:

 intersect-[0-9][0-9][0-9][0-9].tab

and the other is

Code:

intersect-[0-9][0-9][0-9][0-9][0-9][0-9].tab

When I tried command:

Code:

ls intersect-[0-9]\{4\}.tab

or

Code:

ls intersect-[0-9]\{6\}.tab

neither worked but with error message:

Code:

ls: cannot access intersect-[0-9]{6}.tab: No such file or directory

It seems my regex is fine as when I used pipeline:

Code:

 ls *.tab | grep intersect-[0-9]\{6\}.tab

I must have missed something with the regex for ls? Anyone please give me clue?
Thanks for help!

You have missed something indeed: shell regexps (aka "globs") and regexps are NOT the same.

See the man page of your shell for a detailed list of file globs, but if they aren't sufficient for your purpose you will have to do like you dike already: "ls | grep <some_regexp>" or something similar (awk, sed, ... all use the same regexps).

I hope this helps.

bakunin