.LP
The command glyph is used to execute arbitrary UNIX commands with single
input and output data streams.
The optional input and output filenames act as connections to
other glyphs, but it is assumed that the command you wish
to execute uses stdin and stdout for I/O.
.LP
Unlike all other commands, the "Command" that you specify can only
be executed after the pane is glyphed, i.e. there is no "EXECUTE" button
on the pane.  The "QUIT" button deletes the pane.
.sp
.LP
WARNING: If the program that you execute uses stderr, you will get
an unhappy face on the glyph when it is executed.
