NAME
End::Eval::Env - Take code from environment variable(s), then eval them
in END block
VERSION
This document describes version 0.004 of End::Eval::Env (from Perl
distribution End-Eval-Env), released on 2022-02-05.
SYNOPSIS
On the command-line:
% PERL_END_EVAL_ENV='use Data::Dump; dd \%INC' perl -MEnd::Eval::Env `which some-perl-script.pl` ...
% PERL_END_EVAL_ENV='use Data::Dump; dd \%INC' PERL5OPT=-MEnd::Eval::Env some-perl-script.pl ...
Customize the environment variables:
% perl -MEnd::Eval::Env=ENVNAME1,ENVNAME2 `which some-perl-script.pl` ...
% PERL5OPT=-MEnd::Eval::Env=ENVNAME1,ENVNAME2 some-perl-script.pl ...
DESCRIPTION
This module allows you to evaluate Perl code(s) in environment
variable(s), in the END block, basically for convenience in one-liners.
If name(s) of environment variables are not specified,
"PERL_END_EVAL_ENV" is the default.
The purpose of Begin::Eval::* and End::Eval::* modules is to allow you
to evaluate some extra Perl code in addition to running your
application, respectively at the beginning and at the end. The code can
be supplied via one of these means: first command-line argument,
environment variable(s). Previously there are Begin::Eval and End::Eval
modules that accept code from import arguments, but the limited syntax
provided by perl's "-M" switch diminishes the usefulness of the modules.
Thus the modules are removed from CPAN.
Use cases include:
* printing \%INC at the start of your program run
% perl -MBegin::Eval::FirstArg /path/to/your-script.pl 'print "$_\n" for sort keys %INC' script-arg1 ...
% PERL_BEGIN_EVAL_END='print "$_\n" for sort keys %INC' perl -MBegin::Eval::Env /path/to/your-script.pl script-arg1 ...
To know which modules are loaded before your program runs.
* printing \%INC at the beginning of your program run
To know all the modules that are loaded during your program run.
* loading a module at the beginning of your program, with some
initialization
Alternatives to using these modules include using "do":
% perl -E 'your-extra-code-before-running-program; do "/path/to/your/script.pl"; your-extra-code-after-running-program'
ENVIRONMENT
DEBUG
Bool. Can be turned on to print the code to STDOUT before eval-ing it.
PERL_END_EVAL_ENV
HOMEPAGE
Please visit the project's homepage at
<https://metacpan.org/release/End-Eval-Env>.
SOURCE
Source repository is at
<https://github.com/perlancar/perl-End-Eval-Env>.
SEE ALSO
Other "End::Eval::*" modules, like End::Eval::FirstArg.
Other "End::*" modules.
Other "Begin::Eval::*" modules.
Other "Devel::End::*" modules (but this namespace is deprecated in favor
of "End").
AUTHOR
perlancar <perlancar@cpan.org>
CONTRIBUTING
To contribute, you can send patches by email/via RT, or send pull
requests on GitHub.
Most of the time, you don't need to build the distribution yourself. You
can simply modify the code, then test via:
% prove -l
If you want to build the distribution (e.g. to try to install it locally
on your system), you can install Dist::Zilla,
Dist::Zilla::PluginBundle::Author::PERLANCAR, and sometimes one or two
other Dist::Zilla plugin and/or Pod::Weaver::Plugin. Any additional
steps required beyond that are considered a bug and can be reported to
me.
COPYRIGHT AND LICENSE
This software is copyright (c) 2022, 2021 by perlancar
<perlancar@cpan.org>.
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.
BUGS
Please report any bugs or feature requests on the bugtracker website
<https://rt.cpan.org/Public/Dist/Display.html?Name=End-Eval-Env>
When submitting a bug or request, please include a test-file or a patch
to an existing test-file that illustrates the bug or desired feature.