#include <sys/types.h>
#include <linux/unistd.h>
"_syscall2(int, tkill, pid_t, tid, int, sig)"
int tkill(pid_t tid, int sig);
DESCRIPTION
The tkill system call is analogous to
kill(2) , except when the specified process is part of a thread group
(created by specifying the CLONE_THREAD flag in the call to clone).
Since all the processes in a thread group have the same PID,
they cannot be individually signalled with kill.
With tkill, however, one can address each process
by its unique TID.
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno
is set appropriately.
ERRORS
EINVAL
An invalid TID or signal was specified.
ESRCH
No process with the specified TID exists.
EPERM
The caller did not have permission to send the signal to the specified
process. For a process to be allowed to send a signal, it must either
have root privileges, or its real or effective user ID must be equal to
the real or saved set-user-ID of the receiving process.
CONFORMING TO
tkill is Linux specific and should not be used in programs that
are intended to be portable.