Bash – regex matching with “locate”

bashlocateregular expression

I'm trying to use the locate command to find files in my home folder, however whenever I try and run this I get no results:

locate -i -l 4 --regexp '^\/home\/jack\/[A-Za-z0-9\/\ ]*(My.)*$'

I've also tried ^\/home\/jack\/^(?!\.)[A-Za-z0-9\/\ ]*(My.)*$ but that returns no results either.

The file I'm looking for just to test it is /home/jack/Music/Foals/My Number.flac

I would like to exclude the results of hidden files from my search.

Best Answer

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.

Related Solutions

Grep ‘OR’ regex problem

With normal regex, the characters (, | and ) need to be escaped. So you should use

$ grep "^ID.*\(ETS\|FBS\)" my_file.txt

You don't need the escapes when you use the extended regex (-E)option. See man grep, section "Basic vs Extended Regular Expressions".

Bash Commands – How to Act on the Results of the Locate Command

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 ...)

Best Answer

Related Solutions

Grep ‘OR’ regex problem

Bash Commands – How to Act on the Results of the Locate Command

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