Re^2: Two hash keys created when '.' is in the string

Oh! Now I feel dumb. See, the second line is there because I need to flag the value as a custom tag, because I am also returning href=, action=, and other 'links'. But I was being really dumb, not realizing that I was creating 2 different keys, one named '$2.cfm' and the other '$2'. <smacks head in disbelief> :)
If you're curious, here's one of my other sections that worked correctly:

while ($_ =~ /(href)[ ="']+(.*?)["'>|\?]/gi) {
# finding linked files
  if (($2 =~ /css/i)|($2 eq $cfm)) {  # skipping css files and links t
+o self
  } else {
    $uniques{"$2"}++;
    $uniques{$2} = "<norm>";
  }
}
[download]

Comment on Re^2: Two hash keys created when '.' is in the string Download Code

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Re^3: Two hash keys created when '.' is in the string by Eimi Metamorphoumai (Deacon) on Nov 24, 2004 at 18:31 UTC
I doubt that actually is working. A few problems: You shouldn't ever need to use `"$2"`. It's just the same thing as `$2`. So you're still assigning two values to the same hash key. The second one overwrites the first, so that `$uniques{"$2"}++;` line does nothing. Also, `\|` is the bitwise or operator. You want `\|\|` or `or`. And finally, running any regexp match overwrites the values of all the number variables (for instance, `$2`), so after checking `$2 =~ /css/i`, `$2` will be undef.	[reply] [d/l] [select]
Re^4: Two hash keys created when '.' is in the string by eric256 (Parson) on Nov 24, 2004 at 18:48 UTC
"And finally, running any regexp match overwrites the values of all the number variables (for instance, $2), so after checking $2 =~ /css/i, $2 will be undef." Not true. Perl doesn't garuntee that it will overright those unless they actualy match. Since that regex isn't doing any captures he should be safe, not that I think its the best way to do it, but its safe. ___________ Eric Hodges	[reply]
Re^5: Two hash keys created when '.' is in the string by ikegami (Patriarch) on Nov 24, 2004 at 19:04 UTC
"Since that regex isn't doing any captures he should be safe" is wrong. Captures or not, $2 is cleared on a successful match. `$cfm = 'moo'; 'moo' =~ /()(.)/; if (($2 =~ /css/i) \|\| ($2 eq $cfm)) { print(defined($2)?1:0, $/); # 1, cause match failed $uniques{$2}++; } 'css' =~ /()(.)/; if (($2 =~ /css/i) \|\| ($2 eq $cfm)) { print(defined($2)?1:0, $/); # 0, cause match succeeded $uniques{$2}++; # $uniques{undef} ??? }` [download]	[reply] [d/l]
Re^5: Two hash keys created when '.' is in the string by Eimi Metamorphoumai (Deacon) on Nov 24, 2004 at 18:55 UTC
You're right, it only resets them on a successful match, not on an attempted match. But it will overwrite all of them if there's a successful match, even if the match doesn't include any parens. So if the string `/css/` matches, `$2` will be undef, and in that case the code won't work right.	[reply] [d/l] [select]
Re^6: Two hash keys created when '.' is in the string by eric256 (Parson) on Nov 24, 2004 at 19:07 UTC
Re^4: Two hash keys created when '.' is in the string by ysth (Canon) on Nov 24, 2004 at 23:36 UTC
You shouldn't ever need to use "$2". It's just the same thing as $2. Not always. Given: `sub foo { $^O=~/((.))/; print for @_ }` (a sub that happens to use a regex before accessing its args), `foo("$2") if "foobar"=~/(...)(...)/` does something very different from `foo($2) if "foobar"=~/(...)(...)/` You should always* put magic variables in quotes when passing to a function to prevent this kind of action-at-a-distance. Another case where you need to double-quote a variable is when using the string bitwise operators on something that happens to have a cached numeric value: `$ perl -le'$x = "41"; 0+$x; print for ("$x" ^ "3"), ($x ^ "3")' 1 42` [download] (Do the noises in my head bother you?)	[reply] [d/l] [select]