Regular Expression - drive me crazy

[ahgan]

I am trying to do a pattern matching for some setup being done previously by others but I thing I got it all wrong. Is there a simpler way of doing this?
For example:
PATTERN: J??[!G]?[!R,!L]EB*[E,H,K,W,L] means

start with J

2nd & 3rd & 5th characters are wildcard matches 1

4th character is not a "G"

6th character is not an "R" or "L"

7th-8th character match "EB"

9th character is a wildcard matches zero or more

follow by a match of either E, H, K, W, or L.

my $pattern = "J??[!G]?[!R,!L]EB*[E,H,K,W,L]"; 
my $data1 = "JMNPAVEBL";  # should match with the pattern 
$pattern =~ s/\,/\|/g; 
$pattern =~ s/\*/\.\*/g; 
$pattern =~ s/\?/\./g; 
while ($pattern =~ /\[\!.*\]/) { 
    $pattern =~ s/\[\!(.*)\]/\(\?\!\[\#\]\)/; #something is really wrong here!
    my $subpattern = $1; 
    $subpattern =~ s/\!//g; 
    $pattern =~ s/#/$subpattern/; 
}
print "Trying to match $data1 with $pattern\n";
if ($data1 =~ /$pattern/i) { 
    print "Found a match!\n"; 
} 
else { 
    print "No matching found!\n"; 
}

[nithinpes]

The pattern for your requirement will be something like:

   /J..[^G].[^RL]EB.*[EHKWL]/
 

Note that '.' will match any character. If you want it to be alphabetic only use [A-Z] instead.
The requirement for 9th character is not very clear-"9th character is a wildcard matches zero or more", Zero or more of what?
However, it would be good if you try to understand regular expressions before posting any further question.

To understand regular expressions better, consider going through perlre.

[ahgan]

Hi nithinpes,

The 9th character is a wildcard zero or more of anything. My confusion is to detect the !G and !R,!L. I didn't know it's translated into [^G] and [^RL]. I thought ^ is for beginning of string. Now I know it can be used to negate the character class. Please forgive my ignorance and thanks for the solution!

[nithinpes]

Hi nithinpes,

The 9th character is a wildcard zero or more of anything. My confusion is to detect the !G and !R,!L. I didn't know it's translated into [^G] and [^RL]. I thought ^ is for beginning of string. Now I know it can be used to negate the character class. Please forgive my ignorance and thanks for the solution!

^ is for beginning of string. But when it it used within character class [], it stands for negation.