tkill(2) -- Linux man page

 

NAME

tkill - send a signal to a single process  

SYNOPSIS

#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.  

SEE ALSO

gettid(2), kill(2)