Re: How to interpolate a hash in a string

[David Emanuel da Costa Santiago]

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Thank you all for your replies. I was able to do what i needed. I
changed a bit the conf files syntax:

conf file 1:
option=value
option2=value2

conf file 2:
property=propertyValue
property2=propertyValue2
property3=${option2} #instead of $OPTS{option2}

Read function: 

sub _read_conf_file{
  my $file = shift;

  open my $FH, '<', $file;

  while(my $line = <$FH>){
    chomp $line;
    $line =~ s/\#.*//;
    next if $line =~ /^\s*$/;

    my( $key, $val ) = split(/=/,$line,2);
      
    next if (!defined $val || $val =~ /^\s*$/);
    $key =~ s/^\s+|\s+$//g;
    $val =~ s/^\s+|\s+$//g;
    
    if ($val=~/\$\{.+?\}/) {
      $val =~ s/\$\{(.+?)\}/$OPTS{$1}/g; #This is very interesting! :-D
    }

    $OPTS{$key}=$val;
  }
  close $FH;
}



Thank you all.


On Tue, 3 Nov 2015 19:34:20 -0800
"$Bill" <dbec...@gmail.com> wrote:

> Re-sending with CC to OP since it didn't make the group.
> 
> On 11/3/2015 14:03, David Emanuel da Costa Santiago wrote:
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> > Hash: SHA256
> >
> >
> > Hello all.
> >
> > I'm trying to interpolate a hash value in a string but i got stuck.
> > I already tried with eval, without any success...
> >
> >
> > I have two conf files in the form
> > conf file 1:
> > option=value
> > option2=value2
> >
> > conf file 2:
> > property=propertyValue
> > property2=propertyValue2
> >
> > I'm loading these files into a hash. But the problem is that i want
> > to access, for example on conf file 2, properties from conf file 1:
> >
> > property3=$HASH{option2}
> >
> >
> > So i'm getting the hash for conf file 2:
> >  
> > %PROPERTIES=(property=>"propertyValue",  property2=>
> > "propertyValue2", property3=> "$HASH{option2}" );  
> >
> > but what i want is:  
> > %PROPERTIES=(property=>"propertyValue",  property2=>
> > "propertyValue2", property3=> "value2" );  
> >
> >
> > this is how i'm reading the files:
> >
> > sub _read_conf_file{
> >    open my $FH, '<', shift @_;
> >    while(<$FH>){
> >      chomp;
> >      s/\#.*//;
> >      /(\S+)\s*=\s*(.+)/;
> >      next if (!defined $1 || !defined $2);
> >      $OPTS{$1}=$2;
> >    }
> >    close $FH;
> > }
> >
> > Does anybody knows how to do this?  
> 
> I would make s simple addition to your syntax to indicate the value
> is to be taken from the first hash using that value as key.  I
> arbitrarily picked '~' to indicate this condition (you could use
> whatever unique marker you want including $HASH and replace my '~'.
> I avoided trying to eval the $OPTS{} in file 2, but you could play
> with that using 2nd version below which accomplishes the same thing
> with eval.
> 
> use strict;
> use warnings;
> use Data::Dumper;
>    $Data::Dumper::Indent=1; $Data::Dumper::Sortkeys=1;
> 
> my $c1 = <<EOD;                       # file 1
> option=value
> option2=value2
> EOD
> 
> my $c2 = <<'EOD';             # file 2
> property=propertyValue
> property2=propertyValue2
> property3=~option2            # arbitrary ~ marker
> EOD
> 
> my %OPTS = ();
> 
> _read_conf_file ($c1);
> _read_conf_file ($c2);
> print (Data::Dumper->Dump([\%OPTS], [qw(%OPTS)]));
> exit;
> 
> sub _read_conf_file {         # modified to handle from vrbls
> instead of files my $src = shift;
> 
> # open my $FH, '<', shift @_;
> # while (<$FH>) {
> foreach (split /\s*\n\s*/, $src) {
> 
>       next if /^\s*#.*/ or /^\s*$/;   # remove blank and
> comment lines
> 
>       if (not /(\S+)\s*=\s*(.+)/) {
>               print "Invalid config file syntax ($_)\n"; next;
>       }
> 
>       my $k = $1 // ''; my $v = $2 // '';
>       if (not $k) { print "Missing key ($_)\n"; next; }
> 
>       if ($v =~ /^~/) {               # if indirect hash assign
>               $OPTS{$k} = $OPTS{substr $v, 1};
>       } else {
>               $OPTS{$k} = $v;
>       }
> }
> # close $FH;
> 
> }
> 
> __END__
> 
> eval version:
> 
> foreach (split /\s*\n\s*/, $src) {
> 
>       next if /^\s*#.*/ or /^\s*$/;   # remove blank and
> comment lines
> 
>       if (not /(\S+)\s*=\s*(.+)/) {
>               print "Invalid config file syntax ($_)\n"; next;
>       }
> 
>       my $k = $1 // ''; my $v = $2 // '';
>       if (not $k) { print "Missing key ($_)\n"; next; }
> 
>       $v = eval $v if $v =~ /^\$/;
>       $OPTS{$k} = $v;
> }
> 

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