LPDEV(8)                   MiNT Programmer's Manual                   LPDEV(8)


NAME
     lpdev - installs the /dev/lp device


SYNOPSIS
     lpdev


DESCRIPTION
     lpdev will  install  /dev/lp  ,  a  buffered  Centronics  device  driver.
     Typically, this command will be put in your mint.cnf file.

     This device is write-only; you won't be able to read anything from it (it
     will behave like /dev/null ). It's also very dumb: the bytes written into
     /dev/lp will be sent without modification to  the  Centronics  port.   In
     fact,  the  only service offered by /dev/lp is buffering: it should allow
     you to print  without  hogging  the  cpu.   To  take  full  advantage  of
     buffering,  you  should write large blocks of data into /dev/lp , not one
     byte at a time, in order to reduce system call overhead.

     The default size of the buffer is 24 kbyte; jobs that print files  bigger
     than that should be put in the background.

     The ioctl modes recognized by this device are:

     FIONREAD, FIONWRITE
          return the number of bytes that can  be  read  from  (always  0)  or
          written to the device.

     TIOCFLUSH
          clears the buffer.

     F_GETLK, F_SETLK, F_SETLKW
          handle file locking on the device.  You  can  only  lock  the  whole
          device, and only with a write-lock; read-locks are ignored.


SEE ALSO
     lpflush(1)


DIAGNOSTICS
     Error messages are reported on standard output, and lpdev exits with  the
     appropriate return-code (usually EACCDN or ENSMEM).

     lpdev: MiNT is not running
          self-explanatory

     lpdev: device "u:\dev\lp" already installed
          self-explanatory

     lpdev: Centronics interrupt already in use
          The MFP interrupt source #0 is already active, probably  because  of
          another spooler.




                                 July, 1993                                  1



LPDEV(8)                   MiNT Programmer's Manual                   LPDEV(8)


     lpdev: not enough memory
          There's no memory left for the circular buffer.

     lpdev: unable to install device
          MiNT couldn't install the  device  for  another  reason  that  those
          mentioned above.


AUTHOR
     Thierry Bousch (bousch@suntopo.matups.fr)


BUGS
     The /dev/lp device can't be opened in exclusive mode; you must  open  it,
     then apply a lock on the file descriptor.

     The file locking functions haven't been tested, so they won't work.









































                                 July, 1993                                  2