pap(3N)                                                   pap(3N)



NAME
     pap_open, pap_read, pap_read_ignore, pap_status, pap_write,
     pap_close - provide AppleTalk Printer Access Protocol (PAP)
     interface

SYNOPSIS
     #include <at/appletalk.h>
     #include <at/pap.h>
     #include <at/nbp.h>

     int pap_open(tuple)
     at_nbptuple_t *tuple;

     int pap_read(fildes, data, len)
     int fildes, len;
     char *data;

     int pap_read_ignore(fildes)
     int fildes;

     char *pap_status(tuple)
     at_nbptuple_t *tuple;

     int pap_write(fildes, data, len, eof, flush)
     int fildes, len;
     int eof, flush;
     char *data;

     int pap_close(fildes)
     int fildes;

DESCRIPTION
     The PAP interface provides applications with access to the
     AppleTalk Printer Access Protocol operations. The following
     routines once intended for a PAP server are no longer
     supported.

        paps_open
        paps_get_next_job
        paps_register
        paps_status
        paps_close


     The routines for the PAP client are:

        pap_open
        pap_read
        pap_read_ignore
        pap_status
        pap_write
        pap_close



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pap(3N)                                                   pap(3N)



     The pap_open routine opens a connection to a PAP server,
     making it accessible through the returned file descriptor.
     It attempts to connect to the server whose name and address
     are contained in the tuple parameter.  The command
     nbp_lookup (see nbp(3N)) may be used to obtain a valid name
     and address for the desired PAP server.

     Upon successful completion, this routine returns a PAP
     client file descriptor connected to the server requested.

     The pap_read routine reads data from a server specified by
     the file descriptor (fildes) parameter. The file descriptor
     must be one that was obtained previously using pap_open.
     The parameters are

          fildes
               A PAP server file descriptor.

          data A pointer to the buffer containing the data to be
               returned.  The maximum data length specified by
               the length parameter is 512 bytes.

          length
               The maximum length to be read.

     Upon successful completion, the number of bytes read is
     returned. A value of 0 is returned when an end-of-file is
     reached.

     The pap_read_ignore routine issues a PAP read request and
     ignores any returned data.  This is used to allow
     LaserWriters to function when they want to return status
     messages.  The parameter is

          fildes
               A PAP client file descriptor returned by an
               earlier pap_open.

     The pap_status routine locates a PAP server and returns a
     pointer to its status string.  The parameter is

          tuple
               A pointer to a tuple structure containing the name
               and address of a PAP server entity.  The routine
               nbp_lookup (see nbp(3N)) may be used to get a
               valid tuple.

     Upon successful completion, a pointer to the string
     containing the PAP server's status is returned.  If the
     printer's status cannot be recovered, NULL is returned.





2                                                      March 1993

pap(3N)                                                   pap(3N)



     The pap_write routine sends the data passed to it to the
     other end of a PAP server session.  The parameters are

          fildes
               A PAP client AppleTalk file descriptor.

          data A pointer to the data being written.

          len  The length of the data being written; this must
               not exceed 512 bytes.

          eof  A Boolean flag indicating whether EOF indication
               is to be sent to the other end of the PAP session
               (after the data has been sent) to indicate that no
               more data will be sent.  Setting eof to true also
               implies flush.

          flush
               A Boolean flag indicating whether data for all
               waiting PAP writes is to be sent to the remote
               end.  Because PAP runs on top of ATP, PAP writes
               are queued until either a complete ATP response is
               available (about 4 KB) or an end-of-message is
               sent.  This call sends an ATP end-of-message,
               which causes all waiting PAP writes to be sent to
               the other end.  This should be done if a higher
               level protocol (for example, a handshake with a
               LaserWriter) needs to do a write followed by a
               read.

     Upon successful completion, a value of 0 is returned.

     The pap_close routine closes an open PAP client file
     descriptor.  The parameter is

          fildes
               The file descriptor to be closed.

     It returns 0 upon successful completion.  If the file
     descriptor is no longer open, it returns -1.

STATUS MESSAGES AND VALUES
     All routines except pap_status return -1 on error with a
     detailed error code in errno:

     EINVAL
          An invalid argument was passed.

     ENETDOWN
          The network interface is down.

     ESHUTDOWN



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pap(3N)                                                   pap(3N)



          The PAP file descriptor has already been closed.

     ETIMEDOUT
          The connection is timed out.

     See open(2), close(2), ioctl(2), read(2), and write(2) for
     additional error codes; see also errors returned by the
     underlying NBP, ATP, and DDP modules.

FILES
     /usr/lib/libat.a
          Archive of object files for these and related routines
SEE ALSO
     atp(3N), ddp(3N), nbp(3N), rtmp(3N)

     Inside AppleTalk







































4                                                      March 1993