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Re: [PBML] Re: Eval and memory problems

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  • merlyn@stonehenge.com
    ... computerdribble Nope , not in there. there is nothing in the FAQ concerning Macro computerdribble expansion. By the way, it s on *YOUR DISK*. No need
    Message 1 of 15 , Jan 8, 2008
      >>>>> "computerdribble" == computerdribble <computerdribble@...> writes:

      computerdribble> Nope , not in there. there is nothing in the FAQ concerning Macro
      computerdribble> expansion.

      By the way, it's on *YOUR DISK*. No need to go off to the net for the FAQ.
      Type "perldoc perlfaq". And you can search it too, which I will now do for
      you, to show you the FAQ *does* cover what you're looking for.

      I suggest you read the subject lines of "perldoc perlfaq" and "perldoc perl"
      weekly until you can recite them from memory. Perl comes with a HUGE amount
      of info, but it's pointless if you don't know what's there.

      $ perldoc -q expand

      Found in /usr/libdata/perl5/pod/perlfaq4.pod
      How do I expand function calls in a string?
      (contributed by brian d foy)

      This is documented in perlref, and although it's not the easiest thing
      to read, it does work. In each of these examples, we call the function
      inside the braces used to dereference a reference. If we have a more
      than one return value, we can construct and dereference an anonymous
      array. In this case, we call the function in list context.

      print "The time values are @{ [localtime] }.\n";

      If we want to call the function in scalar context, we have to do a bit
      more work. We can really have any code we like inside the braces, so we
      simply have to end with the scalar reference, although how you do that
      is up to you, and you can use code inside the braces.

      print "The time is ${\(scalar localtime)}.\n"

      print "The time is ${ my $x = localtime; \$x }.\n";

      If your function already returns a reference, you don't need to create
      the reference yourself.

      sub timestamp { my $t = localtime; \$t }

      print "The time is ${ timestamp() }.\n";

      The "Interpolation" module can also do a lot of magic for you. You can
      specify a variable name, in this case "E", to set up a tied hash that
      does the interpolation for you. It has several other methods to do this
      as well.

      use Interpolation E => 'eval';
      print "The time values are $E{localtime()}.\n";

      In most cases, it is probably easier to simply use string concatenation,
      which also forces scalar context.

      print "The time is " . localtime . ".\n";

      How do I expand tabs in a string?
      You can do it yourself:

      1 while $string =~ s/\t+/' ' x (length($&) * 8 - length($`) % 8)/e;

      Or you can just use the Text::Tabs module (part of the standard Perl
      distribution).

      use Text::Tabs;
      @expanded_lines = expand(@lines_with_tabs);

      How can I expand variables in text strings?
      Let's assume that you have a string that contains placeholder variables.

      $text = 'this has a $foo in it and a $bar';

      You can use a substitution with a double evaluation. The first /e turns
      $1 into $foo, and the second /e turns $foo into its value. You may want
      to wrap this in an "eval": if you try to get the value of an undeclared
      variable while running under "use strict", you get a fatal error.

      eval { $text =~ s/(\$\w+)/$1/eeg };
      die if $@;

      It's probably better in the general case to treat those variables as
      entries in some special hash. For example:

      %user_defs = (
      foo => 23,
      bar => 19,
      );
      $text =~ s/\$(\w+)/$user_defs{$1}/g;




      --
      Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503 777 0095
      <merlyn@...> <URL:http://www.stonehenge.com/merlyn/>
      Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
      See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl training!
    • computerdribble
      Thank you. I went onto the faq.perl.org site and searched through all of that and nothing came back. This is one of the problems and reasons I have stayed
      Message 2 of 15 , Jan 8, 2008
        Thank you.

        I went onto the faq.perl.org site and searched through all of that
        and nothing came back.

        This is one of the problems and reasons I have stayed away from perl
        for so long. There's SO much to it and it HAS its OWN quirkiness that
        outpaces other languages.


        but again, thank you!


        Now, one other question....


        this works:
        $text =~ s/(\$\w+)/$1/eeg

        it takes;
        $aa="hello";
        $bb="goodbye";


        and inserts it into;


        $text = "( ( $aa =~ /lo/ ) and ($bb =~ /ye/ ) )";


        perfectly to create:


        ( ( hello =~ /lo/ ) and ( goodbye =~ /ye/ ) )



        notice the problem ? No quotes around the $aa expanded variable. So the
        if ( @{ [ $text ] } )

        always fails.



        I'm NOT a regex person and stumble my way through it so far.. but this
        is beyond me at the moment. (yes more reading is required)

        How do I get the expansion (or can it be done? ) to automatically put
        the quotes around the variables expanded?

        I can add the quotes into the database around the variables, but then
        its a cludge.

        thanks again and thanks in advance...


        joe















        --- In perl-beginner@yahoogroups.com, merlyn@... wrote:
        >
        > >>>>> "computerdribble" == computerdribble <computerdribble@...>
        writes:
        >
        > computerdribble> Nope , not in there. there is nothing in the FAQ
        concerning Macro
        > computerdribble> expansion.
        >
        > By the way, it's on *YOUR DISK*. No need to go off to the net for
        the FAQ.
        > Type "perldoc perlfaq". And you can search it too, which I will now
        do for
        > you, to show you the FAQ *does* cover what you're looking for.
        >
        > I suggest you read the subject lines of "perldoc perlfaq" and
        "perldoc perl"
        > weekly until you can recite them from memory. Perl comes with a
        HUGE amount
        > of info, but it's pointless if you don't know what's there.
        >
        > $ perldoc -q expand
        >
        > Found in /usr/libdata/perl5/pod/perlfaq4.pod
        > How do I expand function calls in a string?
        > (contributed by brian d foy)
        >
        > This is documented in perlref, and although it's not the easiest
        thing
        > to read, it does work. In each of these examples, we call the
        function
        > inside the braces used to dereference a reference. If we have a more
        > than one return value, we can construct and dereference an anonymous
        > array. In this case, we call the function in list context.
        >
        > print "The time values are @{ [localtime] }.\n";
        >
        > If we want to call the function in scalar context, we have to do
        a bit
        > more work. We can really have any code we like inside the
        braces, so we
        > simply have to end with the scalar reference, although how you
        do that
        > is up to you, and you can use code inside the braces.
        >
        > print "The time is ${\(scalar localtime)}.\n"
        >
        > print "The time is ${ my $x = localtime; \$x }.\n";
        >
        > If your function already returns a reference, you don't need to
        create
        > the reference yourself.
        >
        > sub timestamp { my $t = localtime; \$t }
        >
        > print "The time is ${ timestamp() }.\n";
        >
        > The "Interpolation" module can also do a lot of magic for you.
        You can
        > specify a variable name, in this case "E", to set up a tied hash
        that
        > does the interpolation for you. It has several other methods to
        do this
        > as well.
        >
        > use Interpolation E => 'eval';
        > print "The time values are $E{localtime()}.\n";
        >
        > In most cases, it is probably easier to simply use string
        concatenation,
        > which also forces scalar context.
        >
        > print "The time is " . localtime . ".\n";
        >
        > How do I expand tabs in a string?
        > You can do it yourself:
        >
        > 1 while $string =~ s/\t+/' ' x (length($&) * 8 - length($`)
        % 8)/e;
        >
        > Or you can just use the Text::Tabs module (part of the standard Perl
        > distribution).
        >
        > use Text::Tabs;
        > @expanded_lines = expand(@lines_with_tabs);
        >
        > How can I expand variables in text strings?
        > Let's assume that you have a string that contains placeholder
        variables.
        >
        > $text = 'this has a $foo in it and a $bar';
        >
        > You can use a substitution with a double evaluation. The first
        /e turns
        > $1 into $foo, and the second /e turns $foo into its value. You
        may want
        > to wrap this in an "eval": if you try to get the value of an
        undeclared
        > variable while running under "use strict", you get a fatal error.
        >
        > eval { $text =~ s/(\$\w+)/$1/eeg };
        > die if $@;
        >
        > It's probably better in the general case to treat those variables as
        > entries in some special hash. For example:
        >
        > %user_defs = (
        > foo => 23,
        > bar => 19,
        > );
        > $text =~ s/\$(\w+)/$user_defs{$1}/g;
        >
        >
        >
        >
        > --
        > Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503
        777 0095
        > <merlyn@...> <URL:http://www.stonehenge.com/merlyn/>
        > Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
        > See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl
        training!
        >
      • Boyle, Christopher
        perldoc -quote ________________________________ From: perl-beginner@yahoogroups.com [mailto:perl-beginner@yahoogroups.com] On Behalf Of computerdribble Sent:
        Message 3 of 15 , Jan 8, 2008
          perldoc -quote



          ________________________________

          From: perl-beginner@yahoogroups.com
          [mailto:perl-beginner@yahoogroups.com] On Behalf Of computerdribble
          Sent: Tuesday, January 08, 2008 3:38 PM
          To: perl-beginner@yahoogroups.com
          Subject: [PBML] Re: Eval and memory problems




          Thank you.

          I went onto the faq.perl.org site and searched through all of that
          and nothing came back.

          This is one of the problems and reasons I have stayed away from perl
          for so long. There's SO much to it and it HAS its OWN quirkiness that
          outpaces other languages.

          but again, thank you!

          Now, one other question....

          this works:
          $text =~ s/(\$\w+)/$1/eeg

          it takes;
          $aa="hello";
          $bb="goodbye";

          and inserts it into;

          $text = "( ( $aa =~ /lo/ ) and ($bb =~ /ye/ ) )";

          perfectly to create:

          ( ( hello =~ /lo/ ) and ( goodbye =~ /ye/ ) )

          notice the problem ? No quotes around the $aa expanded variable. So the
          if ( @{ [ $text ] } )

          always fails.

          I'm NOT a regex person and stumble my way through it so far.. but this
          is beyond me at the moment. (yes more reading is required)

          How do I get the expansion (or can it be done? ) to automatically put
          the quotes around the variables expanded?

          I can add the quotes into the database around the variables, but then
          its a cludge.

          thanks again and thanks in advance...

          joe

          --- In perl-beginner@yahoogroups.com
          <mailto:perl-beginner%40yahoogroups.com> , merlyn@... wrote:
          >
          > >>>>> "computerdribble" == computerdribble <computerdribble@...>
          writes:
          >
          > computerdribble> Nope , not in there. there is nothing in the FAQ
          concerning Macro
          > computerdribble> expansion.
          >
          > By the way, it's on *YOUR DISK*. No need to go off to the net for
          the FAQ.
          > Type "perldoc perlfaq". And you can search it too, which I will now
          do for
          > you, to show you the FAQ *does* cover what you're looking for.
          >
          > I suggest you read the subject lines of "perldoc perlfaq" and
          "perldoc perl"
          > weekly until you can recite them from memory. Perl comes with a
          HUGE amount
          > of info, but it's pointless if you don't know what's there.
          >
          > $ perldoc -q expand
          >
          > Found in /usr/libdata/perl5/pod/perlfaq4.pod
          > How do I expand function calls in a string?
          > (contributed by brian d foy)
          >
          > This is documented in perlref, and although it's not the easiest
          thing
          > to read, it does work. In each of these examples, we call the
          function
          > inside the braces used to dereference a reference. If we have a more
          > than one return value, we can construct and dereference an anonymous
          > array. In this case, we call the function in list context.
          >
          > print "The time values are @{ [localtime] }.\n";
          >
          > If we want to call the function in scalar context, we have to do
          a bit
          > more work. We can really have any code we like inside the
          braces, so we
          > simply have to end with the scalar reference, although how you
          do that
          > is up to you, and you can use code inside the braces.
          >
          > print "The time is ${\(scalar localtime)}.\n"
          >
          > print "The time is ${ my $x = localtime; \$x }.\n";
          >
          > If your function already returns a reference, you don't need to
          create
          > the reference yourself.
          >
          > sub timestamp { my $t = localtime; \$t }
          >
          > print "The time is ${ timestamp() }.\n";
          >
          > The "Interpolation" module can also do a lot of magic for you.
          You can
          > specify a variable name, in this case "E", to set up a tied hash
          that
          > does the interpolation for you. It has several other methods to
          do this
          > as well.
          >
          > use Interpolation E => 'eval';
          > print "The time values are $E{localtime()}.\n";
          >
          > In most cases, it is probably easier to simply use string
          concatenation,
          > which also forces scalar context.
          >
          > print "The time is " . localtime . ".\n";
          >
          > How do I expand tabs in a string?
          > You can do it yourself:
          >
          > 1 while $string =~ s/\t+/' ' x (length($&) * 8 - length($`)
          % 8)/e;
          >
          > Or you can just use the Text::Tabs module (part of the standard Perl
          > distribution).
          >
          > use Text::Tabs;
          > @expanded_lines = expand(@lines_with_tabs);
          >
          > How can I expand variables in text strings?
          > Let's assume that you have a string that contains placeholder
          variables.
          >
          > $text = 'this has a $foo in it and a $bar';
          >
          > You can use a substitution with a double evaluation. The first
          /e turns
          > $1 into $foo, and the second /e turns $foo into its value. You
          may want
          > to wrap this in an "eval": if you try to get the value of an
          undeclared
          > variable while running under "use strict", you get a fatal error.
          >
          > eval { $text =~ s/(\$\w+)/$1/eeg };
          > die if $@;
          >
          > It's probably better in the general case to treat those variables as
          > entries in some special hash. For example:
          >
          > %user_defs = (
          > foo => 23,
          > bar => 19,
          > );
          > $text =~ s/\$(\w+)/$user_defs{$1}/g;
          >
          >
          >
          >
          > --
          > Randal L. Schwartz - Stonehenge Consulting Services, Inc. - +1 503
          777 0095
          > <merlyn@...> <URL:http://www.stonehenge.com/merlyn/
          <http://www.stonehenge.com/merlyn/> >
          > Perl/Unix/security consulting, Technical writing, Comedy, etc. etc.
          > See PerlTraining.Stonehenge.com for onsite and open-enrollment Perl
          training!
          >


          ______________________________________________________________________
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        • Jenda Krynicky
          From: computerdribble ... Compile each test just once and run it repeatedly. Before opening the log file, but after reading the
          Message 4 of 15 , Jan 8, 2008
            From: "computerdribble" <computerdribble@...>
            > The "specific things" are stored in a mysql database as a regex expression
            > Example:
            >
            > ( ( $field =~ /blah/) and ($field =~ /that/) )
            >
            > I open the MySql database, no problem, load the contents into arrays,
            > no problem.
            >
            > Open the log file (approx 1.48megs in size) for reading only.
            >
            > I have a logic loop
            >
            > grab a line from the log file
            >
            > run all regex expressions against the log line grabbed. This could be
            > from 1 to 500 different tests.
            >
            >
            > its done in a EVAL statement.
            >
            > similar to:
            >
            > if ( eval $array[$vartoarraycontents] )

            Compile each test just once and run it repeatedly.
            Before opening the log file, but after reading the expressions do
            something like

            for my $test (@array) {
            $test = eval 'sub { ' . $test . '}'
            or die "Failed to compile '$test' : $@\n";
            }

            and then while looping through the logfile use

            if ($array[$vartoarraycontents]->()) {

            There is a possible catch though! The variables you plan to make
            available to the tests must be declared before the tests are compiled
            by those eval('sub {'...) statements!

            Jenda
            ===== Jenda@... === http://Jenda.Krynicky.cz =====
            When it comes to wine, women and song, wizards are allowed
            to get drunk and croon as much as they like.
            -- Terry Pratchett in Sourcery
          • Computer-Dribble
            Thank you! One problem I ran into was the EVAL was killing 4 gigs of memeory on large log files. At least I traced it back to that. This is why I wanted to
            Message 5 of 15 , Jan 9, 2008
              Thank you!


              One problem I ran into was the EVAL was killing 4 gigs
              of memeory on large log files. At least I traced it
              back to that.

              This is why I wanted to avoid EVAL completely and do
              some macro expansion.

              thanks again!!

              Joe.

              --- Jenda Krynicky <Jenda@...> wrote:

              > From: "computerdribble" <computerdribble@...>
              > > The "specific things" are stored in a mysql
              > database as a regex expression
              > > Example:
              > >
              > > ( ( $field =~ /blah/) and ($field =~ /that/) )
              > >
              > > I open the MySql database, no problem, load the
              > contents into arrays,
              > > no problem.
              > >
              > > Open the log file (approx 1.48megs in size) for
              > reading only.
              > >
              > > I have a logic loop
              > >
              > > grab a line from the log file
              > >
              > > run all regex expressions against the log line
              > grabbed. This could be
              > > from 1 to 500 different tests.
              > >
              > >
              > > its done in a EVAL statement.
              > >
              > > similar to:
              > >
              > > if ( eval $array[$vartoarraycontents] )
              >
              > Compile each test just once and run it repeatedly.
              > Before opening the log file, but after reading the
              > expressions do
              > something like
              >
              > for my $test (@array) {
              > $test = eval 'sub { ' . $test . '}'
              > or die "Failed to compile '$test' : $@\n";
              > }
              >
              > and then while looping through the logfile use
              >
              > if ($array[$vartoarraycontents]->()) {
              >
              > There is a possible catch though! The variables you
              > plan to make
              > available to the tests must be declared before the
              > tests are compiled
              > by those eval('sub {'...) statements!
              >
              > Jenda
              > ===== Jenda@... === http://Jenda.Krynicky.cz
              > =====
              > When it comes to wine, women and song, wizards are
              > allowed
              > to get drunk and croon as much as they like.
              > -- Terry Pratchett in Sourcery
              >
              >
              >
              > Unsubscribing info is here:
              > http://help.yahoo.com/help/us/groups/groups-32.html
              > Yahoo! Groups Links
              >
              >
              > mailto:perl-beginner-fullfeatured@yahoogroups.com
              >
              >
              >



              ____________________________________________________________________________________
              Never miss a thing. Make Yahoo your home page.
              http://www.yahoo.com/r/hs
            • Jenda Krynicky
              - No I don t. And others don t either. - But you do not need to read what I wrote originaly and what you replied last time, you remember it, don t you? -
              Message 6 of 15 , Jan 9, 2008
                - No I don't. And others don't either.
                - But you do not need to read what I wrote originaly and what you
                replied last time, you remember it, don't you?
                - Because it's all backwards.
                - Why is that?
                - Because it's hard to read.
                - Why?
                - Please do not top-post!

                Since the proposed change decreases the number of eval""s from
                (number of tests)*(number of lines in logfile)
                to just
                (number of tests)
                any leaks in eval"" should be irrelevant.

                Jenda

                From: Computer-Dribble <computerdribble@...>
                > One problem I ran into was the EVAL was killing 4 gigs
                > of memeory on large log files. At least I traced it
                > back to that.
                >
                > This is why I wanted to avoid EVAL completely and do
                > some macro expansion.
                >
                > thanks again!!
                >
                > Joe.
                >
                > --- Jenda Krynicky <Jenda@...> wrote:
                >
                > > From: "computerdribble" <computerdribble@...>
                > > > The "specific things" are stored in a mysql
                > > database as a regex expression
                > > > Example:
                > > >
                > > > ( ( $field =~ /blah/) and ($field =~ /that/) )
                > > >
                > > > I open the MySql database, no problem, load the
                > > contents into arrays,
                > > > no problem.
                > > >
                > > > Open the log file (approx 1.48megs in size) for
                > > reading only.
                > > >
                > > > I have a logic loop
                > > >
                > > > grab a line from the log file
                > > >
                > > > run all regex expressions against the log line
                > > grabbed. This could be
                > > > from 1 to 500 different tests.
                > > >
                > > >
                > > > its done in a EVAL statement.
                > > >
                > > > similar to:
                > > >
                > > > if ( eval $array[$vartoarraycontents] )
                > >
                > > Compile each test just once and run it repeatedly.
                > > Before opening the log file, but after reading the
                > > expressions do
                > > something like
                > >
                > > for my $test (@array) {
                > > $test = eval 'sub { ' . $test . '}'
                > > or die "Failed to compile '$test' : $@\n";
                > > }
                > >
                > > and then while looping through the logfile use
                > >
                > > if ($array[$vartoarraycontents]->()) {
                > >
                > > There is a possible catch though! The variables you
                > > plan to make
                > > available to the tests must be declared before the
                > > tests are compiled
                > > by those eval('sub {'...) statements!
                > >
                > > Jenda
                > > ===== Jenda@... === http://Jenda.Krynicky.cz
                > > =====
                > > When it comes to wine, women and song, wizards are
                > > allowed
                > > to get drunk and croon as much as they like.
                > > -- Terry Pratchett in Sourcery
                > >
                > >
                > >
                > > Unsubscribing info is here:
                > > http://help.yahoo.com/help/us/groups/groups-32.html
                > > Yahoo! Groups Links
                > >
                > >
                > > mailto:perl-beginner-fullfeatured@yahoogroups.com
                > >
                > >
                > >
                >
                >
                >
                > ____________________________________________________________________________________
                > Never miss a thing. Make Yahoo your home page.
                > http://www.yahoo.com/r/hs
                >
                >
                > Unsubscribing info is here: http://help.yahoo.com/help/us/groups/groups-32.html
                > Yahoo! Groups Links
                >
                >
                >
                >


                ===== Jenda@... === http://Jenda.Krynicky.cz =====
                When it comes to wine, women and song, wizards are allowed
                to get drunk and croon as much as they like.
                -- Terry Pratchett in Sourcery
              • computerdribble
                I humbly thank ALL who have read or responded. Can you, with all of the examples to date... do away with the EVAL of the variable that contains the testing
                Message 7 of 15 , Jan 9, 2008
                  I humbly thank ALL who have read or responded.

                  Can you, with all of the examples to date...
                  do away with the EVAL of the variable that contains the testing
                  information and just do a straight macro expansion ?

                  $this = "that"
                  $that ="this"

                  $test = ' ( ( "that" =~ /at/) and ( "this" =~ /at/ ) ) '

                  something like @{[ $$test ] }


                  I'm sorry to have ruffled so many feathers, but just because one has
                  20 years of experience in a language does not mean they should look
                  down on someone TRYING to learn it. Much less understand it andits
                  quirkiness.

                  Usually, a pre-madonna is a target in the computer field, remember that.

                  I find that perl is never as straight forward as one thinks. It takes
                  a great deal of trial and error to get it to do what you want it to do
                  .. for a beginner, its frustrating. For someone with 30 years
                  experince in other languages, its VERY frustrating. Unless I
                  completely dive into the language full time.. I'll never gain the
                  knowledge you guys have. But I don't need to. This is a 1 time
                  thing. I can go someone else to find the answers BUT... I thought
                  that this was a "perl-beginner" group/forum not a "lets pick on
                  someone trying to learn the language" area.
                  Is this what "knowledge sharing" has degraded to ?

                  Most of the "trial and error" is because of the REGEX. Each language,
                  has its own way of looking at REGEX and Perl is notorious for its own
                  quirks.

                  I bow before greater GODs than I in the Perl field and I humbly do so.
                  If I had my way, I would have written this in another language
                  altogether, but a client wants what a client wants.

                  As for "top loading or top responding" Not my fault, blame Yahoo for
                  doing that way.. hell blame the whole freaking internet for it,
                  because that's just how it is done. Talk to the hand.






                  Joe.
                • Jenda Krynicky
                  From: computerdribble ... No. You can t. It s as simple as that. If you did not store the expression like this in the database,
                  Message 8 of 15 , Jan 9, 2008
                    From: "computerdribble" <computerdribble@...>
                    > I humbly thank ALL who have read or responded.
                    >
                    > Can you, with all of the examples to date...
                    > do away with the EVAL of the variable that contains the testing
                    > information and just do a straight macro expansion ?
                    >
                    > $this = "that"
                    > $that ="this"
                    >
                    > $test = ' ( ( "that" =~ /at/) and ( "this" =~ /at/ ) ) '
                    >
                    > something like @{[ $$test ] }

                    No. You can't. It's as simple as that.

                    If you did not store the expression like this in the database, but
                    instead stored the name of the variable and the regexp (and nothing
                    else) in separate columns you could do something like

                    if ($data{$varname} =~ /$regexp/) {

                    where the $varname and $regexp comes from the database. Whether that
                    would be enough for you, I don't know.

                    Even in this case though it would be better to preprocess the
                    regexps:

                    foreach my $test (@tests) {
                    # $test = [$varname, $regexp]
                    eval {
                    $test[1] = qr/$test[1]/
                    } or die qq{Invalid regexp /$test[1]/ : $@\n};
                    }

                    This way the regexps are parsed and compiled just once instead of
                    each time they are used.

                    > I'm sorry to have ruffled so many feathers, but just because one has
                    > 20 years of experience in a language does not mean they should look
                    > down on someone TRYING to learn it. Much less understand it andits
                    > quirkiness.
                    >
                    > ...

                    I think all this was unnecessary. Noone's picking on you.

                    > As for "top loading or top responding" Not my fault, blame Yahoo for
                    > doing that way.. hell blame the whole freaking internet for it,
                    > because that's just how it is done. Talk to the hand.

                    The fact that Yahoo (by default?) formats replies one way doesn't
                    mean you have to keep it that way. Top-posting is quite OK for
                    personal emails to a single recipient. For mailing lists its ... not
                    working too well. Always try to make it easy to the people you are
                    asking for help, even if it means you spend two more minutes
                    formatting the email.

                    Jenda
                    ===== Jenda@... === http://Jenda.Krynicky.cz =====
                    When it comes to wine, women and song, wizards are allowed
                    to get drunk and croon as much as they like.
                    -- Terry Pratchett in Sourcery
                  • computerdribble
                    Thank you for responding. ... dang it all! oh well. ... I would love to.. except there are certain instances that what needs to be checked is.. well let me
                    Message 9 of 15 , Jan 9, 2008
                      Thank you for responding.


                      --- In perl-beginner@yahoogroups.com, "Jenda Krynicky" <Jenda@...> wrote:
                      >
                      > From: "computerdribble" <computerdribble@...>
                      > > I humbly thank ALL who have read or responded.
                      > >
                      > > Can you, with all of the examples to date...
                      > > do away with the EVAL of the variable that contains the testing
                      > > information and just do a straight macro expansion ?
                      > >
                      > > $this = "that"
                      > > $that ="this"
                      > >
                      > > $test = ' ( ( "that" =~ /at/) and ( "this" =~ /at/ ) ) '
                      > >
                      > > something like @{[ $$test ] }
                      >
                      > No. You can't. It's as simple as that.
                      >


                      dang it all!
                      oh well.


                      > If you did not store the expression like this in the database, but
                      > instead stored the name of the variable and the regexp (and nothing
                      > else) in separate columns you could do something like
                      >
                      > if ($data{$varname} =~ /$regexp/) {
                      >
                      > where the $varname and $regexp comes from the database. Whether that
                      > would be enough for you, I don't know.
                      >
                      > Even in this case though it would be better to preprocess the
                      > regexps:
                      >
                      > foreach my $test (@tests) {
                      > # $test = [$varname, $regexp]
                      > eval {
                      > $test[1] = qr/$test[1]/
                      > } or die qq{Invalid regexp /$test[1]/ : $@\n};
                      > }
                      >


                      I would love to.. except there are certain instances that what needs
                      to be checked is.. well let me put it this way:


                      (( $field =~ /this/) and ( ($field =~ /that/) or ($field1 =~/a/) or
                      $field2 =~/xx/) or... or.... or.....) )

                      actually some of the rules/checks are quite extensive. I **wish**
                      they were easier.. but they are not and will probably be redefined to
                      something more tighter.. looking for VERY specific things.



                      I appreciate all of the help and guidance.


                      joe






                      > This way the regexps are parsed and compiled just once instead of
                      > each time they are used.
                      >
                      > > I'm sorry to have ruffled so many feathers, but just because one has
                      > > 20 years of experience in a language does not mean they should look
                      > > down on someone TRYING to learn it. Much less understand it andits
                      > > quirkiness.
                      > >
                      > > ...
                      >
                      > I think all this was unnecessary. Noone's picking on you.
                      >
                      > > As for "top loading or top responding" Not my fault, blame Yahoo for
                      > > doing that way.. hell blame the whole freaking internet for it,
                      > > because that's just how it is done. Talk to the hand.
                      >
                      > The fact that Yahoo (by default?) formats replies one way doesn't
                      > mean you have to keep it that way. Top-posting is quite OK for
                      > personal emails to a single recipient. For mailing lists its ... not
                      > working too well. Always try to make it easy to the people you are
                      > asking for help, even if it means you spend two more minutes
                      > formatting the email.
                      >
                      > Jenda
                      > ===== Jenda@... === http://Jenda.Krynicky.cz =====
                      > When it comes to wine, women and song, wizards are allowed
                      > to get drunk and croon as much as they like.
                      > -- Terry Pratchett in Sourcery
                      >
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