I have been using the below syntax in an awk script.

I have large file that consists of 12 columns each separated by a blank space.

Below search criteria works for me on redhat linux 4 and the same syntax shows me no results on redhat linux 5 for the same input file.

/[^[:blank:]]+[[:blank:]]+([[:digit:]\.]+[[:blank:]]+){12,}/

when i remove the 12 it works fine again .I just want to know how does this syntax works .

let me know if you have any questions ?