How do I use grep to search for the string "-1"

Question

I'm using grep in bash to search for the string "-1" .

I would usually search for "bar" like this ...

glaucon@foo $ grep -irn "bar"

... which works fine but when I try to search for "-1" I get this ...

glaucon@foo $ grep -irn "-1"
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.

... I thought the minus might be a special character but it appears not . I also tried using the 'fixed strings' option in case this was some aspect of regex I was unfamiliar with ...

glaucon@foo $ grep -irnF "-1"
Usage: grep [OPTION]... PATTERN [FILE]...
Try 'grep --help' for more information.

... but, as shown, that doesn't provide output either.

I'm sure this is straightforward but ... how ?

Thanks

Related: How to hand over arguments containing “-” in Bash? — steeldriver, Sep 12 '19 at 23:10
It seems that just escaping the "-" will work: grep -irn "\-1" — schrodingerscatcuriosity, Sep 12 '19 at 23:19
@guillermochamorro - thanks. I thought I had tried that but it turns out that I hadn't, that works. As you were first do you want to make this an answer I can mark as 'correct' ? — glaucon, Sep 12 '19 at 23:41
@steeldriver thanks for the link as a result of which I now know that this will also work : grep -irn -e "-1" . — glaucon, Sep 12 '19 at 23:41
@glaucon yes that's what I'd probably use in the special case of grep; for GNU utilities more generally, the -- end-of-options placeholder is my go-to — steeldriver, Sep 12 '19 at 23:44

score 5 · Accepted Answer · edited Dec 30 '20 at 18:16

5

An option you have is to escape the dash - with a backslash \:

grep -irn "\-1"

Adding two dashes to mark the end of options (as suggested by @steeldriver):

grep -irn -- "-1"

Or, use -e to explicitly say "the next argument is the pattern":

grep -irn -e "-1"

edited Dec 30 '20 at 18:16

Kusalananda

333,661

answered Sep 12 '19 at 23:45

schrodingerscatcuriosity

12,396

How do I use grep to search for the string "-1"

1 Answers1