Hugs also consults a number of environment variables on systems that support them. The method for setting these varies with the system.
EMACS
(Windows only) If this variable is set, Hugs is assumed to be running in an Emacs subshell (with different line termination conventions on input).
HOME
The user's home directory.
This is substituted for {Home} in the argument of the
-P
option
(see Section 3.1.2),
and for "~" in the argument of the
:cd command
(see Section 2.4).
HUGSFLAGS
Additional options for Hugs, processed before any given on the command line (see Section 3.1). The following example assumes a shell compatible with the Unix Bourne shell:
HUGSFLAGS='+k -E"vi +%d"' export HUGSFLAGS
HUGSDIR
The Hugs library directory.
This is substituted for {Hugs} in the argument of the
-P
option
(see Section 3.1.2).
This directory should also contain an include
subdirectory, which ffihugs will search for include
files, particularly HsFFI.h
(see Section 4.2).
IGNORE_USER_REGISTRY
(Windows only) If this variable is set, options are not read from the user portion of the Registry (see Section 3.1). You might use this to recover if your registry settings get messed up somehow.
LC_CTYPE
The locale used for external representation of Haskell Char values (see Section 3.3).
SHELL
The shell that is invoked by the :! command (see Section 2.4).