Re: [grep] Searching with star and files with a name starting with a dash

[Davide Brini]

On Tuesday 25 May 2010 15:50:54 Pierre Morin wrote:
> Hello.
> 
> I think I found a "bug" with grep in the way I use it.
> I use grep to search a string recursively on files.
> 
> For exemple if I search the string "Unix" in all the files of /etc, I go
> under "/etc" in my terminal and then I run the command "grep -r 'Unix'
> *".
> It runs just fine so far.
> But I had the mad idea to name a file with a dash at the beginning of
> the name (exemple : "-test").
> And there, I can see that the name of the file "-test" is interpreting
> by the command as an option.
> 
> It's not a real big bug but I think it's strange to have a file name
> interpreting as an option of a command.
> 
> Here is how to have the bug :
> - create a file with name beginning with a dash ("-test" for exemple)
> - in the folder containing the file, run the command "grep -r
> 'WhatEverYouWant" *"

The usual way to avoid that is to use the -- separator that tells the command 
where the options end, so

grep -r -- somepattern *

should work for you. This is a generic convention for most tools, not just 
grep. A workaround could have been

grep -r somepattern ./*

and also note that in this specific case you could also have done

grep -r somepattern .

to get a similar result (and possibly include more files/directories in the 
search). Using * also has the potential problem of triggering an "argument 
list too long" error if * expands to a huge number of arguments, although that 
limit should be fairly high these days (or even no longer present in Linux 
ISTR).

-- 
D.