Strip all comment from perl file using perl / PPR

Question

I have a file with the following content:

sub is_top_level0 { # with comment
print '\nFollowed by comment \n'; # The comment

# line from begin
}

I'm, basically, using the following code where $sFilename is set to the right file name:

use PPR;

    open(DATAIN, $sFilename);
    my @aFileData = map({ s/\r$//g; $_; } <DATAIN>);
    close (DATAIN);
    my $aRawFileData= \@aFileData;
    printf("Read:\n@{$aRawFileData}===============\n");
    my $aUncommentFileData = PPR::decomment($aRawFileData);
    printf("Uncomment:\n@{$aUncommentFileData}===============\n");

The output is:

Read:
sub is_top_level0 { # with comment
 print '\nFollowed by comment \n'; # The comment

 # line from begin
 }
===============
Uncomment:
sub is_top_level0 { # with comment
 print '\nFollowed by comment \n'; # The comment

 # line from begin
 }
===============

as can be seen the part named "Uncomment" still contains the comments.

How to handle this?

(Note problem might sound a bit silly, but I'm not a perl programmer, just trying to modify some existing code)

Edit: small clarification as I wrote in the comment on the answer from @Dada (and that has been added in the answer as well):

Probably not clear enough in the question, but I would like to have the data available in an array $aRawFileData and $aUncommentFileData (with the line terminators \n) so I can iterate over the arrays (as it is done at the moment).

Answer 1

PPR::decomment takes a string as argument, cf the documentation:

It takes a single argument: a string containing the course code

Here, you are calling it on $aRawFileData, which is an arrayref (used as a string, it looks like ARRAY(0x.....); which doesn't contain any # and is thus left as is by PPR::decomment)

Instead of reading your source code line by line, you should read it as a single string, store that in a variable, and pass it to PPR::decomment:

use File::Slurp;

my $sFilename = "test.pl";
my $source_code = read_file($sFilename);
my $without_comments = PPR::decomment($source_code);

print $without_comments;

You might want to still remove the \r after reading the file. In that case add

$source_code =~ s/\r$//g;

after reading your input.

I've used File::Slurp to read the whole file at once. If you'd like another method to do that, have a look at the question What is the best way to slurp a file into a string in Perl?.

If you need the lines of your file in an array, you can then split your string:

my @lines = split /\n/, $without_comments;

If you want the newlines (\n) to be kept, then use:

my @lines = split /(?<=\n)/, $without_comments;