Very beginner question

[ODoisnea]

I feel strange putting such a simple question on this list, but then
again, that is why I did not join the experts list.

Any how, if I have a file called try.txt with the following line:

(name = john)

if I am trying to just extract john for the value $b, why would the
following script not work.  I thought it would take bothIt returns the
full (name=john)

#!user/local/bin/perl -w

open TRY , try.txt;

while (TRY) {
(my $b=$_) =~ s/^(\() (\w+)/$2/;
print $b;
}


Thank you for humiliating me with this simple question.

Olivier
The one who still has a long way to go with Perl

Re: Very beginner question

[Jeff Pinyan]

On May 9, [EMAIL PROTECTED] said:

(name = john)

if I am trying to just extract john for the value $b, why would the
following script not work.  I thought it would take bothIt returns the
full (name=john)

Let's run your regex through the regex explainer:

   (my $b=$_) =~ s/^(\() (\w+)/$2/;

NODE EXPLANATION
--
(?-imsx: group, but do not capture (case-sensitive)
 (with ^ and $ matching normally) (with . not
 matching \n) (matching whitespace and #
 normally):
--
  ^the beginning of the string
--
  (group and capture to \1:
--
\(   '('
--
  )end of \1
--
   ' '
--
  (group and capture to \2:
--
\w+  word characters (a-z, A-Z, 0-9, _) (1 or
 more times (matching the most amount
 possible))
--
  )end of \2
--
)end of grouping
--

You can see that it's matching a '(', and then a ' '.  You don't have a
space after the ( though. :(

Perhaps you want to use:

  while (TRY) {
my ($name) = /^\(\w+ = (\w+)\)$/;
print got: $name\n;
  }

That regex matches the (, and then some word, then  = , and then saves
the next word it finds.

-- 
Jeff japhy Pinyan  [EMAIL PROTECTED]  http://www.pobox.com/~japhy/
Are you a Monk?  http://www.perlmonks.com/ http://forums.perlguru.com/
Perl Programmer at RiskMetrics Group, Inc. http://www.riskmetrics.com/
Acacia Fraternity, Rensselaer Chapter. Brother #734

RE: Very beginner question

[King, Jason]

[EMAIL PROTECTED] writes ..

(name = john)
-
if I am trying to just extract john for the value $b, why would the
following script not work.  I thought it would take bothIt returns the
full (name=john)

#!user/local/bin/perl -w

open TRY , try.txt;

while (TRY) {
   (my $b=$_) =~ s/^(\() (\w+)/$2/;
   print $b;
}


in the name of TMTOWTDI

  while(TRY)
  {
chop( my $name = substr $_, rindex( $_, ' ')+1);
print $name, \n;
  }

but I suspect (from the statement about the output being '(name=john)') that
those spaces might not always be there .. in which case

  while(TRY)
  {
/=\s*(.*)\)/  print $1, \n;
  }

-- 
  jason king

  In Denmark, if a horse carriage is trying to pass a car and the horse
  gets uneasy, the car is required to pull over and stop. If necessary
  to ease the horse down, you are required to cover the car up. -
  http://dumblaws.com/