int gspool_ptrmon(const intfd, void (*fn)(const int))
DESCRIPTION
Note that this routine is not available in the Windows version, please
see the section on gspool_setmon, which covers both jobs and
printers.
The gspool_ptrmon() function is used to set the function fn to be
called upon notification of any changes to the printers list.
fd is a file descriptor previously returned by gspool_open
fn is a function which must be declared as returning void and
taking one "const int" argument. Alternatively, this may be "NULL"
to cancel monitoring.
The function fn will be called with fd as an argument upon each
change to the printer list.
Please note that any changes to the printer list is reported as the
API does not record which printers the user is interested in.
RETURN VALUES
The function gspool_ptrmon() returns 0 if successful otherwise the
error code "GSPOOL_INVALID_FD" if the file descriptor is
invalid. Invalid fn parameters will not be detected and the
application program will probably crash.
Copyright (c) 2009 Free Software Foundation, Inc.
This is free software. You may redistribute copies of it under the
terms of the GNU General Public License
<http://www.gnu.org/licenses/gpl.html>.
There is NO WARRANTY, to the extent permitted by law.