2.11. Emulation for UNIX SystemV lp and lpstat

Many utilities in the UNIX System V environment require the lp, lpstat, and cancel programs. It is almost impossible to modify these utilities, as many are vintage software which is unsupported or which would be too costly to update. In order to support these applications LPRng emulates the lp, lpstat, and clean programs. See the LPRng man pages for lp, lpstat, and cancel in the LPRng distribution for details and compatibility.

The LPRng lpstat emulator accepts the lpstat command line options returns status in a format that is close to the one that common lpstat implementations return. Unfortunately, due to the wide variety of different modifications and vendor versions of lpstat there are slight differences between the this status and the status returned by the original lpstat. If this is the case, then there is little to do but to modify the source code for lpstat and compile a version that implements the required format.

If the lpr program is invoked with the name lp, it will simulate the lp options. This can be done by making a symbolic link to the lpr program or by making a copy of the lpr program with the name lp.

    h4: {59} # cd /usr/bin
    h4: {60} # ln -s lpr lp
    h4: {61} # lp /tmp/hi
    request id is root@h4+489

Finally, if the lprm program is invoked with the name cancel it will simulate the cancel command. This can be done by making a symbolic link to the lprm program or by making a copy of the lprm program with the name cancel.

    h4: {62} # cd /usr/bin
    h4: {63} # ln -s lprm cancel
    h4: {64} # cancel 489
    cancel 513
    Printer lp@h9:
      checking perms 'root@h9+513'
      dequeued 'root@h9+513'

Many vintage or legacy applications have fully qualified paths to the lp and lpstat executables, and it may be necessary to make additional symbolic links or copies of the LPRng executables to satisfy their pathname requirements.

    h4: {65} # ln -s /usr/bin/lpr /usr/ucb/lpr