How to express this in regular expression? - regex

Question

I need to capture all Upper and Lower case character strings other than "FOO" and "BAR". How to do this?
I tried [^(^FOO$)(^BAR$)] but it doesn't work.
Update:
Actually I'm using this in a context, I am concatenating it with another regex
["(\w)+": _this_regex_ ]
For example ["abc":FOO] shouldn't be matched
All other types say ["abc":BAZ] should match

Answer 1

You want a negative look ahead:
\["(\w+)"\s*:\s*(?!FOO\b|BAR\b)(\w+)]
The (\w+) are capturing group, they store the key/value pairs inside variables (I guess that's what you want to do?)
(?!...) is a negative lookahead: it will cause the regex to fail if what's inside matches.
\b is a word-boundary: here it will make the loohahead match (and so fail the regex) only if FOO is followed by a non alphanum character (so ["foo": FOOLISH] will be accepted by the regex)
\s is a short for all type of whitespaces (spaces, tabs, newlines etc)
Demo: http://regex101.com/r/fM3uZ7
What you tried [^...] was a negative character range: it matches any character (and only one character) that's not inside the character range. And keep in mind that inside character ranges only ], ^ and - are special character (so $ means \$ and so on)

Answer 2

Have a try with:
(?i)^(?!.*foo)(?!.*bar)
In action within perl script:
my $re = qr~(?i)^(?!.*foo)(?!.*bar)~;
while(<DATA>) {
chomp;
say (/$re/ ? "OK : $_" : "KO : $_");
}
__DATA__
["abc":FOO]
["abc":BAZ]
output:
KO : ["abc":FOO]
OK : ["abc":BAZ]
Explanation:
The regular expression:
(?i)^(?!.*foo)(?!.*bar)
matches as follows:
NODE EXPLANATION
----------------------------------------------------------------------
(?i) set flags for this block (case-
insensitive) (with ^ and $ matching
normally) (with . not matching \n)
(matching whitespace and # normally)
----------------------------------------------------------------------
^ the beginning of the string
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
.* any character except \n (0 or more times
(matching the most amount possible))
----------------------------------------------------------------------
foo 'foo'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------
(?! look ahead to see if there is not:
----------------------------------------------------------------------
.* any character except \n (0 or more times
(matching the most amount possible))
----------------------------------------------------------------------
bar 'bar'
----------------------------------------------------------------------
) end of look-ahead
----------------------------------------------------------------------