[ новости /+++ | форум | теги | ]

NAME

     Env - perl module that imports environment variables as
     scalars or arrays



SYNOPSIS
         use Env;
         use Env qw(PATH HOME TERM);
         use Env qw($SHELL @LD_LIBRARY_PATH);




DESCRIPTION
     Perl maintains environment variables in a special hash named
     `%ENV'.  For when this access method is inconvenient, the
     Perl module `Env' allows environment variables to be treated
     as scalar or array variables.

     The `Env::import()' function ties environment variables with
     suitable names to global Perl variables with the same names.
     By default it ties all existing environment variables (`keys
     %ENV') to scalars.  If the `import' function receives
     arguments, it takes them to be a list of variables to tie;
     it's okay if they don't yet exist. The scalar type prefix
     '$' is inferred for any element of this list not prefixed by
     '$' or '@'. Arrays are implemented in terms of `split' and
     `join', using `$Config::Config{path_sep}' as the delimiter.

     After an environment variable is tied, merely use it like a
     normal variable.  You may access its value

         @path = split(/:/, $PATH);
         print join("\n", @LD_LIBRARY_PATH), "\n";

     or modify it

         $PATH .= ":.";
         push @LD_LIBRARY_PATH, $dir;

     however you'd like. Bear in mind, however, that each access
     to a tied array variable requires splitting the environment
     variable's string anew.

     The code:

         use Env qw(@PATH);
         push @PATH, '.';

     is equivalent to:

         use Env qw(PATH);
         $PATH .= ":.";

     except that if `$ENV{PATH}' started out empty, the second
     approach leaves it with the (odd) value "`:.'", but the
     first approach leaves it with "`.'".

     To remove a tied environment variable from the environment,
     assign it the undefined value

         undef $PATH;
         undef @LD_LIBRARY_PATH;




LIMITATIONS
     On VMS systems, arrays tied to environment variables are
     read-only. Attempting to change anything will cause a
     warning.



AUTHOR
     Chip Salzenberg <chip@fin.uucp> and Gregor N. Purdy
     <gregor@focusresearch.com>









Поиск по тексту MAN-ов: 


























Партнёры:










Хостинг:










Закладки на сайте

Проследить за страницей


Created 1996-2024 by Maxim Chirkov

Добавить, Поддержать, Вебмастеру