Chapter 39. Environment Variables

Perl uses the following environment variables. This does not include the environment variables used by library packages.

HOME

Used if chdir has no argument.

LC_ALL, LC_CTYPE, LC_COLLATE, LC_NUMERIC, PERL_BADLANG, LANGUAGE, LANG

Controls how Perl handles data specific to particular natural languages.

LOGDIR

Used if chdir has no argument and HOME is not set.

PATH

Used in executing subprocesses, and in finding the Perl script if -S is used.

PERL5LIB

A colon-separated list of directories to search for Perl library files before looking in the standard library and the current directory.

PERL5DB

The command to get the debugger code.

PERL_ENCODING

Used by use encoding without an explicit encoding name.

PERLIO

A space- or colon-separated list of I/O layers. This list becomes the default for all I/O operations.

PERLLIB

Used instead of PERL5LIB if PERL5LIB is not defined.

PERL5OPT

Initial (command-line) options for Perl.

PERL5SHELL

The shell that Perl must use internally for executing system commands. Microsoft ports only.

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