Miscellaneous information about the system environment.
getArgs returns a list of the program's command
line arguments (not including the program name).
getProgName returns the name of the program as it was
However, this is hard-to-impossible to implement on some non-Unix
OSes, so instead, for maximum portability, we just return the leafname
of the program as invoked. Even then there are some differences
between platforms: on Windows, for example, a program invoked as foo
is probably really
FOO.EXE, and that is what
getProgName will return.
var returns the value
of the environment variable
This computation may fail with:
System.IO.Error.isDoesNotExistErrorif the environment variable does not exist.