Example

   /*
    *   This is an example of using mrd_prevent_allow(3mrd) to
    *   prevent or allow media removal, where allowed.  For
    *   robot name on the command line, the desired version
    *   of the command will be used according lock value.
    *   name.
    *
    *   Usage:
    *
    *      mrd_prevent_allow lock-value robot [ robot... ]
    */
   #ifndef   lint
   static   char   SccsId[] = "@(#)mrd_prevent_allow.c   1.2 3/5/97" ;
   #endif

   #include <stdio.h>
   #include <stdlib.h>
   #include <mrd_common.h>
   #include <mrd_message.h>

   main(int argc, char *argv[])
   {
      int      rc ;      /* Counter */
      int      lock ;      /* Lock value */
      int      status ;   /* return status */
      char      *robot ;   /* Robot to open */
      robot_info_t   robot_info ;   /* Robot data */
      dev_status_t   dev_status ;   /* Device status */
      char      log_info[MRD_MAX_LOG_STRING+1] ;

      /*
       *   Check that there are enough arguments.
       */
      if( argc < 3 ) {
         printf("usage: %s lock-value robot [ robot... ]\n", argv[0]) ;
         exit(1) ;
      }
      else
         lock  = atoi(argv[1]) ;

      /*
       *   Initialize the channel field of the robot_info, so
       *   mrd_startup(3mrd) will actually open the robot.
       */
      robot_info.channel = BAD_CHANNEL ;

      for(rc = 2; rc < argc; rc++) {
         /*
          *   The robot for this command.
          */
         robot = argv[rc] ;

         status = mrd_startup(robot, &robot_info, log_info) ;

         if( status != MRD_STATUS_SUCCESS ) {
            printf("Startup failed on %s: %s.\n", robot,
               mrd_strstatus(status)) ;

            continue ;
         }

         printf("Lock value %d on %s.\n", lock, robot) ;

         status = mrd_prevent_allow(&robot_info, lock, &dev_status) ;

         if( status != MRD_STATUS_SUCCESS )
            printf("Prevent/Allow failed on %s: %s.\n", robot,
               mrd_strstatus(status)) ;

         (void)mrd_shutdown(&robot_info) ;
      }

      return 0 ;
   }