Regex Optimization Question

gawatkins has asked for the wisdom of the Perl Monks concerning the following question:

I have a set of strings returned from a function depicting Active Directory user accounts. The string is in the form of:

Win32_Account.Domain="ADDomain",Name="aduser1"
Win32_Account.Domain="ADDomain",Name="aduser2"
Win32_Account.Domain="ADDomain",Name="aduser3"
Win32_Account.Domain="ADDomain",Name="aduser4"
[download]

I would like to change the format to read:

ADDomain\aduser1
ADDomain\aduser2
ADDomain\aduser3
ADDomain\aduser4
[download]

So they can easily be understood on a report. I am currently using the following code to perform this task.

#!/usr/bin/perl -w

use strict;
use warnings;

my $string = q/ Win32_Account.Domain="ADDomain",Name="aduser1"/;
my ( $domain, $uname ) = split( ",", $string );

$domain =~ s/\"//ig; 
$domain =~ s/Win32_Account.Domain=//ig; 
$uname  =~ s/\"//ig;
$uname  =~ s/Name=//ig;

#concat the parts or replace with Account Deleted if SID not found
my $user = ( $uname eq "" ? "Account Deleted" : $domain . "\\" . $unam
+e );
print $user;
[download]

Although the code works, is there a more efficient way to do the work. Any advice would be welcomed.

Thank you,
Greg W.

Update:

Changed the output, Thanks Roy Johnson.
Replaced #/ with #!/, Thanks ikegami

Comment on Regex Optimization Question Select or Download Code

Replies are listed 'Best First'.
Re: Regex Optimization Question by Roy Johnson (Monsignor) on Mar 23, 2006 at 18:57 UTC
This seems to do basically what you want. I just extract what's between quotes and join them together with a backslash. Updated to handle "Account Deleted". `use strict; use warnings; my $string = q/ Win32_Account.Domain="ADDomain",Name="aduser1"/; for my $string (q/ Win32_Account.Domain="ADDomain",Name="aduser1"/, q/ Win32_Account.Domain="ADDomain",Name=""/) { my @fields = $string =~ /"(.?)"/g; printf "New string is (%s)\n", $fields[1] eq '' ? 'Account deleted' +: join '\\', @fields; }` [download] Caution:* Contents may have been coded under pressure.	[reply] [d/l]
Re: Regex Optimization Question by duff (Parson) on Mar 23, 2006 at 18:54 UTC
I think I'd probably do it like this: `$string =~ /Win32_Account.Domain="(.?)",Name="(.?)"/; print $2 eq "" ? "Account Deleted" : "$1\\$2";` [download] But I don't know if that's more efficient as you haven't told us what axis of efficiency you're interested in. There's efficiency in execution time, efficiency in memory usage, efficiency in programmer time, etc. Generally programmer time is the most important thing to optimize for, so if you understand my version and it does what you want, then maybe it's more efficient. :-) duff	[reply] [d/l]
Re^2: Regex Optimization Question by ikegami (Patriarch) on Mar 23, 2006 at 20:05 UTC
Using $1, $2, etc without knowing if the regexp matched is dangerous. For example, `foreach ('foo', 'bar') { /(oo)/; print("$1\n"); }` [download] outputs `oo oo` [download]	[reply] [d/l] [select]
Re^3: Regex Optimization Question by aweeraman (Novice) on Mar 23, 2006 at 20:28 UTC
True. I've found that in these cases, doing the regex with pattern memory in its own code block works. `foreach ('foo', 'bar') { { /(oo)/; print("$1\n"); } }` [download]	[reply] [d/l]
Re^4: Regex Optimization Question by ikegami (Patriarch) on Mar 23, 2006 at 21:54 UTC
Re^2: Regex Optimization Question by JavaFan (Canon) on May 16, 2011 at 09:37 UTC
There's efficiency in execution time, efficiency in memory usage, efficiency in programmer time, etc. Generally programmer time is the most important thing to optimize for, IMO, it's actually very, very rare if there's a situation where you can pinpoint "the most important thing to optimize for". In fact, I cannot think of any. Generally, they are all important, and it takes a good programmer/manager/project leader to strike the right balance.	[reply]
Re^3: Regex Optimization Question by duff (Parson) on Jun 29, 2011 at 17:48 UTC
Indeed. However, not having any information about where to focus on efficiencies, you can't go wrong on "programmer time" as a sane default thing to optimize. That's why it's generally the most important thing and not specifically the most important thing. :-) duff	[reply]
Re^4: Regex Optimization Question by JavaFan (Canon) on Jul 03, 2011 at 20:14 UTC
Re: Regex Optimization Question by ikegami (Patriarch) on Mar 23, 2006 at 19:59 UTC
`#/usr/bin/perl -w` should be `#!/usr/bin/perl -w` You're `-w` is being ignored because of the missing `!`.	[reply] [d/l] [select]
Re^2: Regex Optimization Question by gawatkins (Monsignor) on Mar 23, 2006 at 20:57 UTC
Thank you, I lost my line during the cut/paste excercise and had to retype it. The -w is equivalent to the `use warnings;` isn't it. I often just leave the #! line out from my win32 scripts. Thank you, Greg W.	[reply] [d/l]
Re^3: Regex Optimization Question by ikegami (Patriarch) on Mar 23, 2006 at 21:54 UTC
It's not quite the same. `-w` is actually equivalent to `BEGIN { $^W = 1; }`. There biggest difference is that `-w` will affect included modules, whereas `use warnings;` only affects the current scope (block or file).	[reply] [d/l] [select]
Re: Regex Optimization Question by davidrw (Prior) on Mar 23, 2006 at 18:59 UTC
Can you just do it in one regex (i'm going to assume the domain and name don't have dbl quotes)? `my $string = q/ Win32_Account.Domain="ADDomain",Name="aduser1"/; print ($string =~ /Win32_Account.Domain="(.+?)",Name="(.+?)"/i) ? $1 . "\\" . $2 : "Account Deleted" ;` [download]	[reply] [d/l]
Re: Regex Optimization Question by graff (Chancellor) on Mar 24, 2006 at 02:38 UTC
If the quotation marks are really reliable, you could do it like this: `my @strings = ( qq/Win32_Account.Domain="ADDomain",Name="aduser1"/, qq/Win32_Account.Domain="foobar",Name=""/, qq/Win32_Account.Domain="ADDomain",Name="aduser2"/, ); for ( @strings ) { my $user = join( "\\", (split /"/)[1,3] ); $user = "Account Deleted" unless ( $user =~ /\S+\\\S+/ ); print "$user\n"; }` [download]	[reply] [d/l]

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