Grab Current Line of SVG File

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

Hello, I have been tasked with "correcting" certain items in SVG files. I have never used Perl and after a crash course (using PerlMonks, Stack Overflow, etc.) I can successfully read the SVG file line by line and correct the necessary lines. My final problem, and this is admittedly because of my inexperience, I cannot figure out how to grab the current line so I can do a smartmatch (or something similar). All I need to do is make sure that the current line starts with "<path" and process that line if so. Below is the (partial) code where I read in the file and loop through the lines to make the corrections. EDIT - Ihave added more of the code to show what I want to do with smartmatch - NOTE thta target is set like so:
my $target = '<path';

 
opendir IN, $dirname;
my @in = grep { /^[^.]/ } readdir IN;
closedir IN;

for my $in (@in) {
  open IN, '<', "$dirname/$in" || next;
  open OUT, '>', "$outdirname/$in" || die "can't open file output/$in"
+;
  foreach(<IN>) { #read file line by line
  
    # Strings to correct Note: Escaped ( with \
    s/rotate\(-180/rotate\(-0/g;
    # Look at the current line
    my @look_in = <IN>;
    # <path is in this line, process line
    if( $target ~~ @look_in) {
        for my $key (keys %stroke_width_hash) {
            s/$key/$stroke_width_hash{$key}/g;
        }
    }
    
    
    # Print out line to OUT file
    print OUT $_;
  }
  close OUT;
  close IN;
}
[download]

I have tried (sad attempts):
Print (<IN>)
Print IN
etc.
But none of these are grabbing the actual text for that line
Any help will be greatly appreciated...
Charles

Comment on Grab Current Line of SVG File Download Code

Replies are listed 'Best First'.
Re: Grab Current Line of SVG File by SuicideJunkie (Vicar) on Apr 17, 2019 at 15:14 UTC
What you would probably want to do is read line by line with: `while (my $line = <IN>) { #Do stuff with $line $line =~ s/rotate\(-180/rotate\(-0/g; #etc }` [download] (The minimalist for loop you have reads the whole file in at once, then loops over the lines with the current line stored in `$_`. Your subsequent code implicitly uses `$_` with the substitutions and whatnot, which is what is tripping you up I believe.) You also have an issue with your `open`s; `"$dirname/$in" \|\| next` is unlikely to do the next, since "$dirname/$in" isn't going to be false. You want to use "or" instead of "\|\|" there for the precedence. You may also want to upgrade to `open my $inFileHandle, '<', "$dirname/$in" or next;`, which will make it easy to pass $inFileHandle into functions in the future, but that's not important for what you're currently doing.	[reply] [d/l] [select]
Re^2: Grab Current Line of SVG File by beginAgain (Novice) on Apr 17, 2019 at 16:14 UTC
You said "with the current line stored in $_" - that saved me - I was able to get the current code to do what I needed with that VERY helpful tidbit and using the index function to check for <path Thank you, Charles	[reply]
Re^2: Grab Current Line of SVG File by beginAgain (Novice) on Apr 17, 2019 at 15:24 UTC
Thank you for the quick response :) I am working with your suggestions now and will get back to you	[reply]
Re: Grab Current Line of SVG File by tangent (Parson) on Apr 17, 2019 at 15:58 UTC
You could try something like this: opendir( my $dir, $dirname ); my @in = grep { /^[^.]/ && -f "$dirname/$_" } readdir( $dir ); closedir $dir; for my $file (@in) { open( my $infile, '<', "$dirname/$file" ) or next; open( my $outfile, '>', "$outdirname/$file" ) or die "can't open f +ile output/$file: $!"; while ( my $line = <$infile> ) { $line =~ s/rotate\(-180/rotate\(-0/g; if ( $line =~ m/$target/ ) { for my $key (keys %stroke_width_hash) { $line =~ s/$key/$stroke_width_hash{$key}/g; } } print $outfile $line; } close $outfile; close $infile; } [download]	[reply] [d/l]
Re^2: Grab Current Line of SVG File by beginAgain (Novice) on Apr 17, 2019 at 16:26 UTC
Thank you for replying :) - I have solved it with something mentioned by another poster - see my comments	[reply]
Re: Grab Current Line of SVG File by haukex (Archbishop) on Apr 17, 2019 at 21:23 UTC
Could you show a short but representative input file and the output you expect for that input? In general, I would very strongly recommend you don't parse XML with regexes, it's extremely brittle. I recommend a proper XML parser such as XML::LibXML, it will make you much happier in the long run.	[reply]
Re: Grab Current Line of SVG File by Anonymous Monk on Apr 18, 2019 at 08:12 UTC
When you can Path::Tiny never opendir. Path tiny Modern Perl Book 2014	[reply]
Re: Grab Current Line of SVG File by dinesh_1308 (Initiate) on Apr 20, 2019 at 17:26 UTC
$_ will help you to grab current line.. Ex:- while (<$filehandler>){ print $_; # this prints line by line if ($_ =~ / # your search pattern goes here/){ } } }	[reply]


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