If you type the name of the program alone on the command line:
mfthen mf displays a `**' prompt, which `is 's way of asking you for an input file name'. (See The
fred
A backslash (`\') can also be typed here.
This causes all subsequent commands at the prompt line to be
interpreted as in a file.
(Concerning the backslash, see The book, Chapter 20:
`More About Macros', pages 179 and 180 in the 1986 edition.)
Thus we can respond to the ** prompt with:
\ input fredor even:
\ ; input fred
The backslash is useful because
certain commands are often executed before a file is input.
In particular, quality printing
(see subsection below)
requires the command mode,
and output magnification
(subsection
)
employs the mag command.
For example:
\mode=localfont; mag=magstep(1); input fred
To read MS-DOS pathnames at the ** prompt, this satisfies :
\input \seldom\fred.mfas does:
d:\seldom\fred.mf