Parsing XML files with regular expressions (Perl)

Question

I am using regular expression to parse XML file (though regexp is not recommended for xml parsing, but i have to use regexp, no other go).

My doubt is how to skip commented lines in XML file, while parsing using Perl.

I want Perl to parse XML file, while skipping commented lines.

Can anyone help me, please.

Thanks Senthil .

Could you show us what you've done so far? And why can't you use modules, such as XML::Parser (which is installed by default with ActivePerl)? — MvanGeest, Jul 30 '10 at 13:28

score 4 · Answer 1 · edited May 23 '17 at 11:47

As bad as this question is for many people, many answers to it are just as bad: use an XML parser, here's why, end of the discussion.

For me, the whole point of asking a question on stackoverflow is to obtain a solution. Have we provided a solution to OP? Not quite.

A more complete answer would offer some examples on how to parse xml. Here are some;

runrig · Answer 2 · 2010-07-30T18:44:26.783

3

If your problem is compiling XML libraries, you can try XML::Parser::Lite or XML::Parser::PurePerl which are pure perl modules requiring no compilation.

Or, you might be able to find pre-compiled packages of the non-pure-perl libraries. What OS are you on?

edited Jul 30 '10 at 18:44

answered Jul 30 '10 at 15:14

runrig

MKDoc::XML is another lightweight pure-perl XML parser which, amusingly enough, uses a monster regex as a tokenizer -- but it's the *right* regex. – hobbs Jul 31 '10 at 05:35

score 2 · Answer 3 · edited May 23 '17 at 11:47

2

At least you can write a simple finite-state machine based parser to process your XML. It's very simple to do it.

edited May 23 '17 at 11:47

Community

answered Jul 30 '10 at 13:31

Daniel O'Hara

2

The OP is aware of it, but doesn't have another option – NullUserException Jul 30 '10 at 13:33
1

to quote op "I am using regular expression to parse XML file (though regexp is not recommended for xml parsing, but i have to use regexp, no other go)." This answer is not useful as he already knows it... bigger question is why he can't use a parser. – xenoterracide Jul 30 '10 at 13:33
I understand this, but I don't understand why he *have to* use regexp. – Daniel O'Hara Jul 30 '10 at 13:40
1

+1 for adding the second paragraph... but i'm with all the others who say "explain why not A CPan parser". – DVK Jul 30 '10 at 14:15
4

Unless it's a homework problem, the OP *does* have other options – derby Jul 30 '10 at 16:15

NullUserException · Accepted Answer · 2010-07-30T14:04:16.787

1

One way to do it is to strip commented lines prior to parsing.

$string =~ s/<!--.*?-->//gs;

edited Jul 30 '10 at 14:04

answered Jul 30 '10 at 13:25

NullUserException

Can you please tell me how to strip off commented lines. I am a new bie. please – Senthil kumar Jul 30 '10 at 13:27
@NullUserException: Only if it's on one line. Or the file needs to be read in slurp mode. – MvanGeest Jul 30 '10 at 13:29
@NullUserException: that won't help if $string has been read like `while ($string = )`, which cuts off a line-sized chunk for reading. – MvanGeest Jul 30 '10 at 13:42
@NullUserException: You'll need the /g flag too. – jmz Jul 30 '10 at 13:45

4 Answers4