Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

.pm Files

by carlriz (Beadle)
on Mar 27, 2014 at 19:47 UTC ( #1079987=perlquestion: print w/replies, xml ) Need Help??
carlriz has asked for the wisdom of the Perl Monks concerning the following question:

I installed a new module on my computer today and while looking at the output of the CPAN installation script, I was curious at what .pm files looked like opened. Now, what I saw did not make sense to me. It is unreadable.

.tr \(*W- .ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p' .ie n \{\ . ds -- \(*W- . ds PI pi . if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo +10 pitch . if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\" diablo +12 pitch . ds L" "" . ds R" "" . ds C` "" . ds C' "" 'br\} .el\{\ . ds -- \|\(em\| . ds PI \(*p . ds L" `` . ds R" '' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode trans +form. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\"

This is just a snippet. What do those cryptic symbols mean?

Replies are listed 'Best First'.
Re: .pm Files
by kcott (Canon) on Mar 27, 2014 at 20:27 UTC

    G'day carlriz,

    If you'd actually named the Perl module, I could provide a more specific answer.

    A Perl module is written in Perl. This is not what you're looking at. As an example, look at the source code for Data::Dumper (which I just picked at random).

    What you've posted is the source code used to generate a manpage. The equivalent code for Data::Dumper starts like this:

    .\" Automatically generated by Pod::Man 2.27 (Pod::Simple 3.28) .\" .\" Standard preamble: .\" ================================================================== +====== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 ..

    As you can see on the first line, this is "generated by Pod::Man". See the Pod::Man documentation for more information (if you're still interested).

    -- Ken

      'Perl library for parsing text in the Pod ("plain old documentation") markup language that is typically used for writing documentation for Perl and for Perl modules'

      I see.

Re: .pm Files
by ww (Bishop) on Mar 27, 2014 at 20:24 UTC

    I would agree that it's not easily comprehended... but "unreadable?" Well, not exactly. There are a lot of hints in the plain-text we can see; hints suggesting some sort of print-oriented device or operation.

    But your actual question is harder to answer, based on what you've told us

    The tool wich which you opened your .pm file with might make a difference -- among other things, in whether this is a typical extract; the entire content of the module; or an intermittent sample, in which the program that opened the file merely threw away characters that weren't in its vocabulary.

    So, please tell us: was it a hex editor; a text editor that will (I don't see any examples here) render certain non-ASCII characters as boxes (and perhaps etc) any editor that quits on anything it takes to be EOF; a debugger? And, not just BTW, in what OS did you open it?


    Questions containing the words "doesn't work" (or their moral equivalent) will usually get a downvote from me unless accompanied by:
    1. code
    2. verbatim error and/or warning messages
    3. a coherent explanation of what "doesn't work actually means.

      Operating System is OS X 10.8.4. And, I opened the file using emacs, a text editor.

Re: .pm Files
by davido (Archbishop) on Mar 27, 2014 at 20:39 UTC

    Keep in mind that a .pm file is usually a module, written in pure Perl. If the specific snippet you're looking at through a drinking straw is incomprehensible, try looking through a little bit wider peephole, and you will find Perl.


    Dave

Re: .pm Files (.pm is just extension)
by Anonymous Monk on Mar 27, 2014 at 20:12 UTC

    What do those cryptic symbols mean?

    it depends, what module did you find that in?

      This is where I found them: File::HomeDir::Test.3pm.

        "This is where I found them: File::HomeDir::Test.3pm."

        Note the extension: ".3pm" not ".pm".

        Also note the double colons (::) in the file name. The filename for File::HomeDir::Test will be just 'Test.pm'. The pathname to the file will end with 'File/HomeDir/Test.pm'.

        -- Ken

        That's the man page (ie. documentation), so the language is probably nroff.

        Try file ....3pm and see what it tells you

Log In?
Username:
Password:

What's my password?
Create A New User
Node Status?
node history
Node Type: perlquestion [id://1079987]
Approved by ww
help
Chatterbox?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others examining the Monastery: (6)
As of 2016-09-30 00:07 GMT
Sections?
Information?
Find Nodes?
Leftovers?
    Voting Booth?
    Extraterrestrials haven't visited the Earth yet because:







    Results (562 votes). Check out past polls.