Home arrow Perl Programming arrow Page 11 - Understanding Perl's Special Variables

End Zone - Perl

Perl comes with a whole bunch of cryptically-named built-invariables, which clever Perl programmers exploit to reduce the number oflines of code in their scripts. This article examines some of the morecommonly-used special variable in Perl, with examples and illustrations ofhow they may be used.

TABLE OF CONTENTS:
  1. Understanding Perl's Special Variables
  2. In Default
  3. Input...
  4. ...And Output
  5. Getting Into An Argument
  6. The Right Path
  7. To Err Is Human
  8. A Question Of Ownership
  9. Rank And File
  10. Calling For A Translator
  11. End Zone
By: icarus, (c) Melonfire
Rating: starstarstarstarstar / 38
July 10, 2003

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And that's about it for this tutorial. Over the preceding few pages, I
introduced you to the following special variables in Perl:

$_ (the default variable)

$/ (the input record separator)

$\ (the output record separator)

$, (the output field separator)

@ARGV (the command-line argument array)

@_ (the subroutine argument array)

@INC (the include path array)

%ENV (the environment variable array)

$? and $! (the last error code)

$@ (the last error in an eval() block)

$<, $>, $) and $( (the real and effective UID/GIDs)

$. (the line number of an input file)

$ARGV (the name of an input file)

$0 (the name of the current script)

$$ (the process ID of the current script)

$[ (the Perl version number)

Of course, these are just some of the more commonly-used creatures you'll
encounter in your travels through the Perl universe. Perl has a whole bunch
more of these special variables which have not been discussed here - you
can find them all in the "perlvar" manual page. Take a look for yourself,
and until we meet again...stay healthy!

Note: Examples are illustrative only, and are not meant for a production
environment. Melonfire provides no warranties or support for the source
code described in this article. YMMV!



 
 
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