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people.2fun

NAME

people - fetch a structure containing all ttys, whose owner behaves like a human

SYNOPSIS

 #include <sys/people.h>
 #include <asr.h>
 
 int people (struct ppl_tty **ttys);
 

DESCRIPTION

The people function fetches a short description of every tty, whose coupled process behaves as an actual human.

It returns a newly malloc'ed array with just enough elements to contain all elements needed for this.

The struct ppl_tty is declared as:

 struct ppl_tty {
   char tty_path[MAX_PATH_LENGTH];
   int is_erratic;
   int uses_jobcontrol;
   int is_amoron;
   int is_aluser;
   int has_aclue;
   pid_t pgrp_leader;
 };
 

RETURN VALUES

On success people returns the number of elements in ttys , on failure it returns -1 and errno is set to an appropriate value.

ERRORS

ENOENT

There are no human-behavioured processes on the system

EBUSY

The kernel is busy and will not stand this silly behaviour. Caution to call people again, from the same process, as the kernel might kill it right away.

ENODEV

See ENOENT above.

EUSERS

Too many of the people found were lusers. The cut-off for this error is system dependent, but is usually about 3.

EXAMPLE

 #include <sys/people.h>
 #include <asr.h>
 #include <signal.h>
 
 int
 main (int argc, char **argv)
 {
   struct ppl_tty **ttys;
   int rv,c;
 
   rv=people(ttys);
   if (rv!=-1) {
     for (c=0;c<rv;c++)
       if ((ttys[c].is_amoron)||(ttys[c].is_aluser)) {
         kill(-(ttys[c].pgrp_leader),SIGKILL);
       }
   } else {
     ; /* Handle errors in a graceful way... */
   }
 }
 

AUTHOR

This man page was written by Ingvar Mattsson, as a contribution to the a.s.r man page collection.