Question

I have a string, “$server[‘fish_stick’]” (disregard double quotes)

I don’t know how to successfully grep for an exact match for this string. I’ve tried many ways.

I’ve tried,

rgrep -i \$'server'\[\''fish'\_'stick'\'\] .

rgrep -i "\$server\[\'fish\_stick\'\]" .

rgrep -i '\$server\[\'fish\_stick\'\]' .

Is it single quotes that are causing my issue?
When I echo the first grep out it shows exactly what I want to search but returns garbage results like anything with $server in it.

Please help and explain, thank you!

Answer 1

The main problem here is that you are not quoting the argument being passed to grep. The only thing that needs to be escaped is \$ (if double quoted) and []. If you want the exact string (not using regex), just use fgrep (grep -F) which does exact string matching:

grep -F "\$server['fish_stick']"

Works on my system:

$ foo="\$server['fish_stick']"
$ echo "$foo" | grep -F "\$server['fish_stick']"
$server['fish_stick']

Using regex:

$ echo "$foo" | grep "\$server\['fish_stick'\]"
$server['fish_stick']

Using regex and handling nested single quotes:

$ echo "$foo" | grep '\$server\['\''fish_stick'\''\]'
$server['fish_stick']

Inside of single quotes, nested single quotes can not be not be escaped. You have to close the quotes, and then reopen it to “escape” the single quotes.

http://mywiki.wooledge.org/Quotes