lpr-command

lpr-command is a variable defined in `lpr.el'.
Its value is

"lpr"

• This variable may be risky if used as a file-local variable.

Documentation:
Name of program for printing a file.

On MS-DOS and MS-Windows systems, if the value is an empty string then
Emacs will write directly to the printer port named by `printer-name'.
The programs `print' and `nprint' (the standard print programs on
Windows NT and Novell Netware respectively) are handled specially, using
`printer-name' as the destination for output; any other program is
treated like `lpr' except that an explicit filename is given as the last
argument.

You can customize this variable.