161181Sbostic.\" Copyright (c) 1980, 1991, 1993 261181Sbostic.\" The Regents of the University of California. All rights reserved. 320032Smckusick.\" 447208Scael.\" %sccs.include.redist.man% 520032Smckusick.\" 6*66931Sbostic.\" @(#)kill.2 8.3 (Berkeley) 04/19/94 747208Scael.\" 847208Scael.Dd 947208Scael.Dt KILL 2 1047208Scael.Os BSD 4 1147208Scael.Sh NAME 1247208Scael.Nm kill 1347208Scael.Nd send signal to a process 1447208Scael.Sh SYNOPSIS 1555759Sbostic.Fd #include <signal.h> 1647208Scael.Ft int 1747208Scael.Fn kill "pid_t pid" "int sig" 1847208Scael.Sh DESCRIPTION 1947208ScaelThe 2047208Scael.Fn kill 2147208Scaelfunction sends the signal given by 2247208Scael.Fa sig 2347208Scaelto 2447208Scael.Fa pid , 2547208Scaela 2647208Scaelprocess or a group of processes. 2747208Scael.Fa Sig 2820033Smckusickmay be one of the signals specified in 2947208Scael.Xr sigaction 2 3020033Smckusickor it may be 0, in which case 3120033Smckusickerror checking is performed but no 3220033Smckusicksignal is actually sent. 3320033SmckusickThis can be used to check the validity of 3447208Scael.Fa pid . 3547208Scael.Pp 3647208ScaelFor a process to have permission to send a signal to a process designated 3747208Scaelby 3847208Scael.Fa pid , 39*66931Sbosticthe real or effective user ID of the receiving process must match 4047208Scaelthat of the sending process or the user must have appropriate privileges 4147208Scael(such as given by a set-user-ID program or the user is the super-user). 4223811SsechrestA single exception is the signal SIGCONT, which may always be sent 4328107Skarelsto any descendant of the current process. 4447208Scael.Bl -tag -width Ds 4547208Scael.It \&If Fa pid No \&is greater than zero : 4647208Scael.Fa Sig 4747208Scaelis sent to the process whose ID is equal to 4847208Scael.Fa pid. 4947208Scael.It \&If Fa pid No \&is zero : 5047208Scael.Fa Sig 5147208Scaelis sent to all processes whose group ID is equal 5247208Scaelto the process group ID of the sender, and for which the 5347208Scaelprocess has permission; 5447208Scaelthis is a variant of 5547208Scael.Xr killpg 2 . 5647208Scael.It \&If Fa pid No \&is -1 : 5765100SmckusickIf the user has super-user privileges, 5847208Scaelthe signal is sent to all processes excluding 5951352Sbosticsystem processes and the process sending the signal. 6051352SbosticIf the user is not the super user, the signal is sent to all processes 6151352Sbosticwith the same uid as the user excluding the process sending the signal. 6228107SkarelsNo error is returned if any process could be signaled. 6347208Scael.El 6447208Scael.Pp 6520999SmckusickFor compatibility with System V, 6647208Scaelif the process number is negative but not -1, 6727199Slepreauthe signal is sent to all processes whose process group ID 6820999Smckusickis equal to the absolute value of the process number. 6920999SmckusickThis is a variant of 7047208Scael.Xr killpg 2 . 7147208Scael.Sh RETURN VALUES 7220033SmckusickUpon successful completion, a value of 0 is returned. 7347208ScaelOtherwise, a value of -1 is returned and 7447208Scael.Va errno 7520033Smckusickis set to indicate the error. 7647208Scael.Sh ERRORS 7747208Scael.Fn Kill 7847208Scaelwill fail and no signal will be sent if: 7947208Scael.Bl -tag -width [EINVAL] 8047208Scael.It Bq Er EINVAL 8147208Scael.Fa Sig 8247208Scaelis not a valid signal number. 8347208Scael.It Bq Er ESRCH 8447208ScaelNo process can be found corresponding to that specified by 8547208Scael.Fa pid . 8647208Scael.It Bq Er ESRCH 8728107SkarelsThe process id was given as 0 8828107Skarelsbut the sending process does not have a process group. 8947208Scael.It Bq Er EPERM 9020033SmckusickThe sending process is not the super-user and its effective 9120033Smckusickuser id does not match the effective user-id of the receiving process. 9247208ScaelWhen signaling a process group, this error is returned if any members 9328107Skarelsof the group could not be signaled. 9447208Scael.El 9547208Scael.Sh SEE ALSO 9647208Scael.Xr getpid 2 , 9747208Scael.Xr getpgrp 2 , 9847208Scael.Xr killpg 2 , 9947208Scael.Xr sigaction 2 10047208Scael.Sh STANDARDS 10147208ScaelThe 10247208Scael.Fn kill 10347208Scaelfunction is expected to 10447208Scaelconform to IEEE Std 1003.1-1988 10547208Scael.Pq Dq Tn POSIX . 106