.\" Copyright 1994 Salvatore Valente (svalente@mit.edu)
.\" Copyright 1992 Rickard E. Faith (faith@cs.unc.edu)
.\" May be distributed under the GNU General Public License
-.TH KILL 1 "July 2014" "util-linux" "User Commands"
+.TH KILL 1 "November 2019" "util-linux" "User Commands"
.SH NAME
kill \- terminate a process
.SH SYNOPSIS
.B kill
.RB [ \- \fIsignal\fR| \-s
-.IR signal | \fB-p\fP ]
+.IR signal | \fB\-p\fP ]
.RB [ \-q
.IR value ]
.RB [ \-a ]
+\fR[\fB\-\-timeout \fImilliseconds signal\fR]
.RB [ \-\- ]
.IR pid | name ...
.br
If a process does not terminate after a TERM signal has been sent,
then the KILL signal may be used; be aware that the latter signal
cannot be caught, and so does not give the target process the opportunity
-to do perform any clean-up before terminating.
+to perform any clean-up before terminating.
.PP
Most modern shells have a builtin kill command, with a usage rather similar to
that of the command described here. The
.BR \-\-all ,
.BR \-\-pid ", and"
-.BR \-\-queue
+.B \-\-queue
options, and the possibility to specify processes by command name, are local extensions.
.PP
If \fIsignal\fR is 0, then no actual signal is sent, but error checking is still performed.
.SH ARGUMENTS
-The list of processes to be signaled can be a mixture of names and pids.
+The list of processes to be signaled can be a mixture of names and PIDs.
.TP
.I pid
Each
.I n
where
.I n
-is larger than 0. The process with pid
+is larger than 0. The process with PID
.I n
is signaled.
.TP
.B 0
All processes in the current process group are signaled.
.TP
-.B -1
-All processes with a pid larger than 1 are signaled.
+.B \-1
+All processes with a PID larger than 1 are signaled.
.TP
-.BI - n
+.BI \- n
where
.I n
is larger than 1. All processes in process group
.I n
-are signaled. When an argument of the form '-n' is given, and it is meant to
+are signaled. When an argument of the form '\-n' is given, and it is meant to
denote a process group, either a signal must be specified first, or the
-argument must be preceded by a '--' option, otherwise it will be taken as the
+argument must be preceded by a '\-\-' option, otherwise it will be taken as the
signal to send.
.RE
.TP
numbers.
.TP
\fB\-a\fR, \fB\-\-all\fR
-Do not restrict the command-name-to-pid conversion to processes with the same
-uid as the present process.
+Do not restrict the command-name-to-PID conversion to processes with the same
+UID as the present process.
.TP
\fB\-p\fR, \fB\-\-pid\fR
-Only print the process ID (pid) of the named processes, do not send any
+Only print the process ID (PID) of the named processes, do not send any
signals.
.TP
\fB\-\-verbose\fR
-Print pid(s) that will be signaled with kill along with the signal.
+Print PID(s) that will be signaled with kill along with the signal.
.TP
\fB\-q\fR, \fB\-\-queue\fR \fIvalue\fR
Use
field of the
.I siginfo_t
structure.
-
+.TP
+\fB\-\-timeout\fR \fImilliseconds signal\fR
+Send a signal defined the usual way to a process.
+.B \-\-timeout
+will make
+.B kill
+to wait for a period defined in
+.I milliseconds
+before sending follow-up
+.I signal
+to process.
+This feature is implemented by PID file-descriptor and guaranties that
+follow-up signals are sent to the same process or not sent if the process no
+more exist. Note that the operating system may re-use PIDs and implement the
+same feature in a shell by kill and sleep commands sequence may introduce a
+race. This option can be specified more than once than signals are sent
+sequentially in defined timeouts. The
+.B \-\-timeout
+option can be combined with
+.B \-\-queue
+option.
+.IP
+Example. Send signals QUIT, TERM and KILL in sequence and wait for 1000
+milliseconds between the signals
+.br
+kill \-\-verbose \-\-timeout 1000 TERM \-\-timeout 1000 KILL \-\-signal QUIT 12345
+.SH EXIT STATUS
+.B kill
+has the following exit status values:
+.PP
+.RS
+.PD 0
+.TP
+.B 0
+success
+.TP
+.B 1
+failure
+.TP
+.B 64
+partial success (when more than one process specified)
+.PD
+.RE
.SH NOTES
Although it is possible to specify the TID (thread ID, see
.BR gettid (2))
For more details, see
.BR signal (7)
and the description of
-.BR CLONE_THREAD
+.B CLONE_THREAD
in
.BR clone (2).
-
-.SH RETURN CODES
-.B kill
-has the following return codes:
-.TP
-.BR 0
-success
-.TP
-.BR 1
-failure
-.TP
-.BR 64
-partial success (when more than one process specified)
-
-.SH SEE ALSO
-.BR bash (1),
-.BR tcsh (1),
-.BR sigaction (2),
-.BR kill (2),
-.BR sigqueue (3),
-.BR signal (7)
-
+.P
+Various shells have provide an internal kill implementation that is
+preferred in relation to the
+.BR kill (1)
+executable described by this manual. Easiest way to ensure one is executing
+the executable is to use full path when calling the command, for example:
+.B "/bin/kill \-\-version"
.SH AUTHORS
.MT svalente@mit.edu
Salvatore Valente
.PP
The original version was taken from BSD 4.4.
+.SH SEE ALSO
+.BR bash (1),
+.BR tcsh (1),
+.BR sigaction (2),
+.BR kill (2),
+.BR sigqueue (3),
+.BR signal (7)
+
.SH AVAILABILITY
The kill command is part of the util-linux package and is available from
-.UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
+.UR https://\:www.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
Linux Kernel Archive
.UE .
projects / thirdparty / util-linux.git / blobdiff