Re: Help with --regex in locate

[rhkramer@gmail.com]

On Tuesday, December 03, 2019 09:01:16 AM Greg Wooledge wrote:
> On Tue, Dec 03, 2019 at 05:54:33AM -0500, Rh Kramer wrote:
> > locate --regex \/\.gitignore
> 
> Your quoting is all wrong here.  What you want is:
> 
> locate --regex '/\.gitignore'
> 
> The / does not need to be quoted, either for the shell, or for the
> regex.  It's just a regular old character with no special meaning.
> The . on the other hand DOES need to be quoted, not for the shell,
> but for the regex.  Because in a regex, it means "any character".
> 
> Within the regex, you quote it by putting a \ in front of it.  However,
> then that backslash needs to be quoted for the SHELL, because otherwise
> the shell interprets it:
> 
> wooledg:~$ echo \.
> .
> 
> See, that's not what you want.  You need to pass the payload /\.gitignore
> as the regex, so you need to quote that in such a way that the shell
> doesn't screw with it.  Thus, the single quotes around it.
> 
> wooledg:~$ echo '/\.gitignore'
> /\.gitignore
> 
> > But I've had no luck finding only the paths that end in .git.
> 
> locate --regex '\.git$'

Thanks that works! (Well, exept for bare repositories, which I'm really not 
concerned about, at least at this time!)

I always have trouble with all the rigamarole around quoting for the shell vs. 
quoting for the regex (or quoting or not quoting for anything else).

I don't know what it will take to get it to sink into my head.  (Maybe in my 
next life ;-)

I do find it useful to think of the backslash as "escaping" vs. "quoting".

> Again, the single quotes protect the regex from interpretation by the
> shell.