Environment Variables

This section lists some environment variables used by Magma. These variables are set by an appropriate operating system command and are used to define various search paths and other run-time options.

MAGMA_STARTUP_FILE

The name of the default start-up file. It can be overridden by the magma -s command.

MAGMA_PATH

Search path for files that are loaded (a colon separated list of directories). It need not include directories for the libraries, just personal directories. This path is searched before the library directories.

MAGMA_MEMORY_LIMIT

Limit on the size of the memory that may be used by a Magma-session (in bytes).

MAGMA_LIBRARY_ROOT

The root directory for the Magma libraries (by supplying an absolute path name). From within Magma SetLibraryRoot and GetLibraryRoot can be used to change and view the value.

MAGMA_LIBRARIES

Give a list of Magma libraries (as a colon separated list of sub-directories of the library root directory). From within Magma SetLibraries and GetLibraries can be used to change and view the value.

MAGMA_SYSTEM_SPEC

The Magma system spec file containing the system packages automatically attached at start-up.

MAGMA_USER_SPEC

The personal user spec file containing the user packages automatically attached at start-up.

MAGMA_HELP_DIR

The root directory for the Magma help files.

MAGMA_TEMP_DIR

Optional variable containing the directory Magma is to use for temporary files. If not specified, this defaults to /tmp (on Unix-like systems) or the system-wide temporary directory (on Windows systems).

MAGMA_NO_HISTORY

If this variable is set to anything at all, Magma keeps no command history: no file is read, written, or made, and no directory either. Unlike the history option (Section The Options File), which is read from a file inside the history directory, it is checked before that directory is made.

MAGMA_CONFIG_DIR

Optional variable naming a directory in which Magma keeps a persistent command history across sessions (Section The History File). The command lines typed in interactive sessions are saved there and reloaded in later sessions, and the directory may also hold an options file setting the history options (Section The Options File). It is created if it does not already exist.

If the variable is not set, Magma uses ~/.magma, creating it if necessary, so a history is kept by default. To keep none, see MAGMA_NO_HISTORY above or the history option (Section The Options File).

MAGMA_HIST_PLAIN

If this variable is set, the session browser (Section Saved Sessions and the Browser) draws a plain, uncoloured display for this run, without editing the options file. Set to dumb, it also makes the browser emit no terminal escape sequences at all, as the browser-plain dumb option does. It can only make the display plainer than the browser-plain option asks for, never fancier.