notes_part_7.txt

---------- Notes on chapter 10 of Beginning Perl (Simon Cozens, 2000). ---------

Including other files:

do FILENAME;
   Searches @INC for FILENAME and executes its contents as Perl script.

require FILENAME;
   Same as "do", but only executes once for each file; will ignore subsequent
   requires for the same file.

use FILENAME;
    Same as "require". but executes before everything else in the program
    no matter where the statement is placed.

To modify @INC: 
   Use the lib pragma:
       use lib "my/module/directory"; 
       use FILENAME; 

----------------------------- PERL STANDARD MODULES ----------------------------

File::Find - Traverse directory	trees, visit each file,	and run	a subroutine
             (the callback) on them. There are 2 subroutines; find & finddepth.
             Find does a depth-first preorder traversal. Finddepth does	a
             postorder traversal.

    use File::Find;
    find(\&wanted, @directories_to_search);
    sub wanted { ... }

    use File::Find;
    finddepth(\&wanted, @directories_to_search);
    sub wanted { ... }

Getopt::Std - Process single-character switches with switch clustering.

Getopt::Long - Same as previous, byt for multicharacter switches.

File::Spec - Module for	handling, constructing, and splitting file names. It
             offers the	following functions:

    canonpath ($path)      cleans up $path to simplest form
    catdir($dir1, $dir2)   concatenates two directories
    catfile($dir, $file)   like catdir, but the path will end with a file name	
    tmpdir()               finds a writeable directory for temp files
    splitpath($path) 	   splits path into volume, directories, and file name
    splitdir($path)        splits path into its constituent directories
    path()                 returns search path for executable files

--------------------------------- CPAN MODULES ---------------------------------

Use the standard module called CPAN to enter the "CPAN Shell".

To enter, input:	
   perl -MCPAN -e shell
Which is the same as saying
   #!/usr/bin/perl
   use CPAN; 
   shell();

To install modules, use install command. For example:
   install DBD::mysql

To get info on a module, use the i command:
   i MLDBM
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