Pass a string or array as arguments in bash

Question

I have excludes as a variable, where it's meant to be a list of regexes to pass to grep:

$ echo $excludes
-e re_1 -e re_2 -e re_3...

I'd like to be able to do something like

$ my | pipeline | grep -v "${excludes}"

but this doesn't work.

I also tried using an array as in grep -v "${excludes[@]}" where each array member is "-e blah". This didn't work either.

How can I pass arguments in a programmatic way like this?

I think this may be one of the cases where you should not quote your variable. — jesse_b, Dec 06 '17 at 19:50
@Jesse_b, only works if the regexes don't contain whitespace, and they'd get used as globs too (unless set -f), which isn't likely to be good since regexes often contain the very same characters that are special in globs... — ilkkachu, Dec 06 '17 at 20:24
Where do your regexes come from? A space-separated string like that seems fiddly if you ever happen to need regexes that contain spaces... — ilkkachu, Dec 06 '17 at 20:31
I control the source of the regexes, so that's not an issue in this case. choroba's answer was what I needed. — Jon Cohen, Dec 06 '17 at 21:25

score 4 · Accepted Answer · edited Dec 06 '17 at 20:40

4

Array works, but you need to store the options and values as separate elements:

excludes=(-e "regex1" -e "regex2")
grep -v "${excludes[@]}" ...

edited Dec 06 '17 at 20:40

glenn jackman

answered Dec 06 '17 at 19:52

choroba

1 Answers1