kill(2) 							System Calls Manual							   kill(2)

NAME

       kill - Sends a signal to a process or to a group of processes

SYNOPSIS

       #include <signal.h>

       int kill(
	       pid_t process,
	       int signal );

       Application  developers	may  want  to  specify an #include statement for <sys/types.h> before the one for <signal.h> if programs are being
       developed for multiple platforms. The additional #include statement is not required on Tru64 UNIX systems or by ISO  or	X/Open	standards,
       but may be required on other vendors' systems that conform to these standards.

STANDARDS

       Interfaces documented on this reference page conform to industry standards as follows:

       kill():	XSH5.0

       Refer to the standards(5) reference page for more information about industry standards and associated tags.

PARAMETERS

       Specifies the process or group of processes.  Specifies the signal. If the signal parameter is a value of 0 (the null signal), error check-
       ing is performed but no signal is sent. This can be used to check the validity of the process parameter.

DESCRIPTION

       The kill() function sends the signal specified by the signal parameter to the process or group of processes specified by the process param-
       eter.

       To  send  a signal to another process, at least one of the following must be true: The real or the saved set-user-ID of the sending process
       matches the real or effective user ID of the receiving process.	The process is trying to send the SIGCONT signal to one of  its  session's
       processes.  The calling process has root privileges.

       Processes can send signals to themselves.

       Sending	a  signal  does  not  imply that the operation is successful. All signal operations must pass the access checks prescribed by each
       enforced access control policy on the system.

       If the process parameter is greater than 0 (zero), the signal specified by the signal parameter is sent to the process that has	a  process
       ID equal to the value of the process parameter.

       If  the	process  parameter  is equal to 0 (zero), the signal specified by the signal parameter is sent to all of the processes (other than
       system processes) whose process group ID is equal to the process group ID of the sender.

       If the process parameter is equal to -1, the signal specified by the signal parameter is sent to all of the  processes  other  than  system
       processes  for  which  the process has permission to send that signal.  For example, if the effective user ID of the sender has root privi-
       leges, the signal specified by the signal parameter is sent to all of the processes other than system processes.

       If the process parameter is negative but not -1, the signal specified by the signal parameter is sent to all of the processes which have  a
       process group ID equal to the absolute value of the process parameter.

RETURN VALUES

       Upon successful completion, the kill() function returns a value of 0 (zero). Otherwise, a value of -1 is returned and errno is set to indi-
       cate the error.

NOTES

       Some applications and scripts depend on the process ID of the init program being 1 (one):  do not depend  on  it.   Instead,  use  standard
       methods, such as the ps and grep commands, to obtain all process IDs.

ERRORS

       The kill() function sets errno to the specified values for the following conditions: The signal parameter is not a valid signal number.

	      [Tru64  UNIX]  The  signal parameter is SIGKILL, SIGSTOP, SIGTSTP or SIGCONT and the process parameter is the process ID of the init
	      program.	No process or process group can be found corresponding to that specified by the process parameter.  The real or saved user
	      ID  does	not match the real or effective user ID of the receiving process, the calling process does not have appropriate privilege,
	      and the process is not sending a SIGCONT signal to one of its session's processes.  [Tru64 UNIX]	The calling process does not  have
	      appropriate privilege.

RELATED INFORMATION

       Functions: getpid(2), killpg(2), raise(3), setpgid(2), sigaction(2), sigvec(2)

       Standards: standards(5) delim off

																	   kill(2)