Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl: the Markov chain saw
 
PerlMonks  

comment on

( [id://3333]=superdoc: print w/replies, xml ) Need Help??
Said robin:
Something that hasn't being mentioned is that all punctuation variables are always global, even if they aren't magical.
I did say this.

The situation with ${^Name} variables is a little more complicated: the fact is that any variable name that starts with a punctuation character is implicitly global, but the Perl parser only recognises single punctuation characters.
The actual rule is that any name that starts with a character other than a letter or underscore is global. (Unless your source code is written in unicode, in which case i don't know what happens.) So in particular, $0 and $1 are global. Variables like ${^Name} don't start with punctuation either: As robin said, this one appears to start with ^, but actually it starts with the control-N character. Since control-N isn't a letter or underscore, ${^Name} is global.

There's one exception to that: you can also use :: as a name, so you can use the variable $:: which is of course global.
Not so. $:: is actually the same variable as $main::main::. (Thanks to Abigail for tracking this down.) There's a special case in gv.c that treats an empty package name as main, and it gets invoked twice here.

--
Mark Dominus
Perl Paraphernalia


In reply to Re: Can you create *real* global variables? by Dominus
in thread Can you create *real* global variables? by broquaint

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.
Log In?
Username:
Password:

What's my password?
Create A New User
Domain Nodelet?
Chatterbox?
and the web crawler heard nothing...

How do I use this?Last hourOther CB clients
Other Users?
Others pondering the Monastery: (None)
    As of 2024-04-25 00:47 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      No recent polls found