Ruby interpreter uses the following environment variables to control its behavior. The ENV object contains a list of all the
current environment variables set.
Variable
Description
DLN_LIBRARY_PATH
Search path for dynamically loaded modules.
HOME
Directory moved to when no argument is passed to Dir::chdir. Also used by File::expand_path to expand "~".
LOGDIR
Directory moved to when no arguments are passed to Dir::chdir and environment variable HOME isn't set.
PATH
Search path for executing subprocesses and searching for Ruby programs with the -S option. Separate each path with a colon (semicolon in DOS and Windows).
RUBYLIB
Search path for libraries. Separate each path with a colon (semicolon in DOS and Windows).
RUBYLIB_PREFIX
Used to modify the RUBYLIB search path by replacing prefix of library path1 with
path2 using the format path1;path2 or path1path2.
RUBYOPT
Command-line options passed to Ruby interpreter. Ignored in taint mode (Where $SAFE is greater than 0).
RUBYPATH
With -S option, search path for Ruby programs. Takes precedence over PATH. Ignored in taint mode (where $SAFE is greater than 0).
RUBYSHELL
Specifies shell for spawned processes. If not set, SHELL or COMSPEC are checked.
For Unix use env command to see a list of all environment variables.