Perl uses several environment variables. With a few exceptions, these all start with PERL.
Library packages and platform-dependent features may have their own environment variables.
These are the most common environment variables:
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.
PERLLIB
Used instead of PERL5LIB
if PERL5LIB
is not defined.
PERL5OPT
Initial (command-line) options for Perl.