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

Here is my updated code. 
#! /u/ss/bin/perl -w

$pattern=qr/
(
^[^=|#]*=\s*\(DESCRIPTION\s*=\s*
\(ADDRESS_LIST\s*=\s*\(ADDRESS\s*=\s*
   \(COMMUNITY\s*=\s*[^)]*\)\s*\(PROTOCOL\s*=\s*TCP\)\s*
   \(HOST\s*=\s*[^)]*\)\s*\(PORT\s*=\s*\d+\)\s*\)\s*\)\s*
 \(CONNECT_DATA\s*=\s*\(SID\s*=\s*[^)]*\)\s*\)\s*
\)\s*
)
/x;
open FILE,"tnsnames.ora" or die $!;
{local $/=undef; $_ = <FILE>; }
close FILE;
print "This is tnsnames.ora\n";
@sections=/$pattern/g;
foreach $el (@sections) {
        print $el;
}
@sorted=sort @sections;
open FILE,"tns.log" or die $!;
{local $/=undef; $_ = <FILE>; }
close FILE;
@sections=/$pattern/g;
print "This is tns.log\n";
foreach $el (@sections) {
        print $el;
}
$x=pop @sorted || '';
print "This is $x\n";
$y=pop @sections || '';
print "This is y: $y\n";
while( $x || $y ){
   if( $x gt $y ){
       #print "missing from file1: $x\n";
       $x = pop @sorted || '';
   }elsif( $y gt $x ){
       #print "missing from file2: $y\n";
      $y = pop @sections || '';
   }else{
       $x = pop @sorted || '';
      $y = pop @sections || '';
   }
}

[download]
When I first try to print the @sections array for the first file there is nothing. when i print it for the 2nd file i get output. I am wondering if my pattern not matching the 1st file but somehow matching the 2nd file. 
example for first file:
###############
# Filename......: tnsnames.ora
# Name..........: LOCAL_REGION.lanier.com
# Date..........: 24-OCT-95 14:30:07
################

##### TF
#####Oracle Application File Server
FNDFS_tf.lanier.com =
    (DESCRIPTION =
       (ADDRESS =
         (COMMUNITY = tcp.lanier.com)
           (PROTOCOL = tcp )
           (HOST = tf.lanier.com)
           (PORT = 1521)
       )
       (CONNECT_DATA =
           ( SID = FNDFS )
       )
    )

sdbet.lanier.com =
  (DESCRIPTION =
    (ADDRESS_LIST =
        (ADDRESS =
          (COMMUNITY = tcp.lanier.com)
          (PROTOCOL = TCP)
          (Host = sb.lanier.com)
          (Port = 1521)
        )
    )
    (CONNECT_DATA =
       (SID = sdbet)
       (GLOBAL_NAME = sdbet.lanier.com)
    )
  )

[download]
I am trying to ignore the lines that start with # in my pattern 
 example of 2nd file:
acp.lanier.com = (DESCRIPTION =
   (ADDRESS_LIST = (ADDRESS =
     (COMMUNITY = tcp.lanier.com) (PROTOCOL = TCP)
     (HOST = st.lanier.com) (PORT = 1533) ) )
   (CONNECT_DATA = (SID = utl) )
 )

acpd.lanier.com = (DESCRIPTION =
   (ADDRESS_LIST = (ADDRESS =
     (COMMUNITY = tcp.lanier.com) (PROTOCOL = TCP)
     (HOST = sp.lanier.com) (PORT = 1531) ) )
   (CONNECT_DATA = (SID = utld) )
 )

[download]

Edit by tye, title, add CODE tags around data

Replies are listed 'Best First'.
Re: Regular Expressions to ignore lines starting with #
by Mr. Muskrat (Canon) on May 19, 2003 at 18:34 UTC

    Instead of using:

    open FILE,"tnsnames.ora" or die $!;
{local $/=undef; $_ = <FILE>; }
close FILE;

    [download]

    I'd probably use something like this:
    open(FILE, '<', 'tnsnames.ora')
  or die "Cannot open tnsnames.ora for reading, stopped ",$!;
my $tnsnames = '';
for (<FILE>) {
  next if /^#/;
  $tnsnames .= $_;
}
close FILE;

    [download]

    It will skip the lines beginning with # and add all the rest into the scalar $tnsnames.

[reply]
[d/l]
[select]
      next if /^#/;

      I'd likely do it similarly but I'd change the regex a bit. Using /^\s*#/ will skip lines where the first non-whitespace character is an octothorpe, not just the first character. That's usually how comments are defined.

      -sauoq
"My two cents aren't worth a dime.";
[reply]

        and i would do it like this: 

          s/#.*$//;
  next if /^$/;

        [download]

        to remove any comment (up to end of line) and skip if there's nothing left. but this might be stretching the requirement a bit.

[reply]
[d/l]
        I use to do it like: 
        next if /^\s*(#.*)?$/;

        [download]
        skipping "empty" lines too, which of course will fail if you use HERE document like constructs.
[reply]
[d/l]

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