OSF

NAME

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

LIBRARY

Berkeley Compatibility Library (libbsd.a)

SYNOPSIS

#include <sys/types.h> #include <signal.h> int kill(
pid_t process;
int signal );

PARAMETERS

processSpecifies the process or group of processes. 

signalSpecifies the signal. If the signal parameter is a value of 0 (the null signal), error checking is performed but no signal is sent. This can be used to check the validity of the process parameter. 

process_grpSpecifies the process group. 

DESCRIPTION

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

To send a signal to another process, at least one of the following must be true:

       •The real or the effective 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 superuser privilege. 

Processes can send signals to themselves. 

NOTES

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 and the effective user ID of the sender has root privileges, 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. 

The killpg() function is provided by OSF/1 for binary compatibility only. 

AES Support Level:
Full use

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 indicate the error. 

ERRORS

If the kill() function fails, no signal is sent and errno may be set to one of the following values:

[EINVAL]The signal parameter is not a valid signal number. 

[EINVAL]The signal parameter is SIGKILL, SIGSTOP, SIGTSTP or SIGCONT and the process parameter is 1 (proc1). 

[ESRCH]No process can be found corresponding to that specified by the process parameter. 

[EPERM]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. 

[EACCES]The calling process does not have appropriate privilege. 

RELATED INFORMATION

Functions: getpid(2), kill(2), setpgid(2), sigaction(2), sigvec(2)