people(2) System Calls Manual people(2)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.
4th Berkeley Distribution Release 0.01 alpha people(2)
Check Out this Related Man Page
OPENPTY(3) BSD Library Functions Manual OPENPTY(3)NAME
openpty, login_tty, forkpty -- tty utility functions
SYNOPSIS
#include <util.h>
int
openpty(int *amaster, int *aslave, char *name, struct termios *termp, struct winsize *winp);
int
login_tty(int fd);
pid_t
forkpty(int *amaster, char *name, struct termios *termp, struct winsize *winp);
DESCRIPTION
The openpty(), login_tty(), and forkpty() functions perform manipulations on ttys and pseudo-ttys.
The openpty() function allocates a pseudo-tty and returns file descriptors for the master and slave in amaster and aslave. If name is non-
null, the filename of the slave is returned in name. If termp is non-null, the terminal parameters of the slave will be set to the values in
termp. If winp is non-null, the window size of the slave will be set to the values in winp.
The login_tty() function prepares for a login on the tty fd (which may be a real tty device, or the slave of a pseudo-tty as returned by
openpty()) by creating a new session, making fd the controlling terminal for the current process, setting fd to be the standard input, out-
put, and error streams of the current process, and closing fd.
The forkpty() function combines openpty(), fork(), and login_tty() to creates a new process operating in a pseudo-tty. The file descriptor
of the master side of the pseudo-tty is returned in amaster, and the filename of the slave in name if it is non-null. The termp and winp
parameters, if non-null, will determine the terminal attributes and window size of the slave side of the pseudo-tty.
RETURN VALUES
If a call to openpty(), login_tty(), or forkpty() is not successful, -1 is returned and errno is set to indicate the error. Otherwise,
openpty(), login_tty(), and the child process of forkpty() return 0, and the parent process of forkpty() returns the process ID of the child
process.
ERRORS
openpty() will fail if:
[EAGAIN] There are no available pseudo-ttys.
login_tty() will fail if ioctl() fails to set fd to the controlling terminal of the current process. forkpty() will fail if either openpty()
or fork() fails.
FILES
/dev/ptmx cloning pseudo-tty device
/dev/ttys[0-9][0-9][0-9] slave pseudo-tty devices
SEE ALSO fork(2)BSD April 5, 2008 BSD