‘locate’ for case-insensitive words

Yes, you can use xargs for this.

For example a simple:

$ locate commands.cfg | xargs grep check_dns

(When grep sees multiple files it searches in each one and enables filename printing along matches.)

Or you can explicitly enable filename printing via:

$ locate commands.cfg | xargs grep -H check_dns

(Just in case one grep is called only with 1 argument by xargs)

For programs that only accept one filename argument (unlike grep) you can restrict the number of supplied arguments like this:

$ locate commands.cfg | xargs -n1 grep check_dns

That does not print the names of files where matched lines are from.

The result is equivalent to:

$ locate commands.cfg | xargs grep -h check_dns

With a modern locate/xargs you can also protect against whitespace issues:

$ locate -0 commands.cfg | xargs -0 grep -H check_dns

(By default whitespace separates input of xargs - which is of course a problem when your filenames contain whitespace ...)

This seems to do the job.

locate -ir '^/home/jack/\([^.][^/]\+/\)\+My[^/]*$'

Quotes from manual:

-i, --ignore-case Ignore case distinctions when matching patterns.

-r, --regexp REGEXP Search for a basic regexp REGEXP. No PATTERNs are allowed if this option is used, but this option can be specified multiple times.