Env - perl module that imports environment variables as scalars or arrays
use Env; use Env qw(PATH HOME TERM); use Env qw($SHELL @LD_LIBRARY_PATH);
Perl Programmers Reference Guide Env(3) NAME Env - perl module that imports environment variables as scalars or arrays SYNOPSIS use Env; use Env qw(PATH HOME TERM); use Env qw($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> ATTRIBUTES See attributes(7) for descriptions of the following attributes: +---------------+-----------------------+ |ATTRIBUTE TYPE | ATTRIBUTE VALUE | +---------------+-----------------------+ |Availability | runtime/perl-532 | +---------------+-----------------------+ |Stability | Pass-through volatile | +---------------+-----------------------+ NOTES Source code for open source software components in Oracle Solaris can be found at https://www.oracle.com/downloads/opensource/solaris-source- code-downloads.html. This software was built from source available at https://github.com/oracle/solaris-userland. The original community source was downloaded from http://www.cpan.org/src/5.0/perl-5.32.0.tar.gz. Further information about this software can be found on the open source community website at https://www.perl.org/. perl v5.32.0 2020-06-14 Env(3)