misc-utils/kill.1

   1 .\" Copyright 1994 Salvatore Valente (svalente@mit.edu)
   2 .\" Copyright 1992 Rickard E. Faith (faith@cs.unc.edu)
   3 .\" May be distributed under the GNU General Public License
   4 .TH KILL 1 "July 2014" "util-linux" "User Commands"
   5 .SH NAME
   6 kill \- terminate a process
   7 .SH SYNOPSIS
   8 .B kill
   9 .RB [ \- \fIsignal\fR| \-s
  10 .IR signal | \fB-p\fP ]
  11 .RB [ \-q
  12 .IR value ]
  13 .RB [ \-a ]
  14 .RB [ \-\- ]
  15 .IR pid | name ...
  16 .br
  17 .B kill \-l
  18 .RI [ number ]
  19 .RB "| " \-L
  20 .SH DESCRIPTION
  21 The command
  22 .B kill
  23 sends the specified \fIsignal\fR to the specified processes or process groups.
  24 If no signal is specified, the TERM signal is sent.  This TERM signal will kill
  25 processes that do not catch it; for other processes it may be necessary to use
  26 the KILL signal (number 9), since this signal cannot be caught.
  27 .PP
  28 Most modern shells have a builtin kill function, with a usage rather similar to
  29 that of the command described here.  The
  30 .BR \-\-all ,
  31 .BR \-\-pid ", and"
  32 .BR \-\-queue
  33 options, and the possibility to specify processes by command name, are local extensions.
  34 .PP
  35 If \fIsignal\fR is 0, then no actual signal is sent, but error checking is still performed.
  36
  37 .SH ARGUMENTS
  38 The list of processes to be signaled can be a mixture of names and pids.
  39 .TP
  40 .I pid
  41 Each
  42 .I pid
  43 can be one of four things:
  44 .RS
  45 .TP
  46 .I n
  47 where
  48 .I n
  49 is larger than 0.  The process with pid
  50 .I n
  51 is signaled.
  52 .TP
  53 .B 0
  54 All processes in the current process group are signaled.
  55 .TP
  56 .B -1
  57 All processes with a pid larger than 1 are signaled.
  58 .TP
  59 .BI - n
  60 where
  61 .I n
  62 is larger than 1.  All processes in process group
  63 .I n
  64 are signaled.  When an argument of the form '-n' is given, and it is meant to
  65 denote a process group, either a signal must be specified first, or the
  66 argument must be preceded by a '--' option, otherwise it will be taken as the
  67 signal to send.
  68 .RE
  69 .TP
  70 .I name
  71 All processes invoked using this \fIname\fR will be signaled.
  72
  73 .SH OPTIONS
  74 .TP
  75 \fB\-s\fR, \fB\-\-signal\fR \fIsignal\fR
  76 The signal to send.  It may be given as a name or a number.
  77 .TP
  78 \fB\-l\fR, \fB\-\-list\fR [\fInumber\fR]
  79 Print a list of signal names, or convert the given signal number to a name.
  80 The signals can be found in
  81 .I /usr/\:include/\:linux/\:signal.h
  82 .TP
  83 \fB\-L\fR, \fB\-\-table\fR
  84 Similar to \fB\-l\fR, but it will print signal names and their corresponding
  85 numbers.
  86 .TP
  87 \fB\-a\fR, \fB\-\-all\fR
  88 Do not restrict the command-name-to-pid conversion to processes with the same
  89 uid as the present process.
  90 .TP
  91 \fB\-p\fR, \fB\-\-pid\fR
  92 Only print the process id (pid) of the named processes, do not send any
  93 signals.
  94 .TP
  95 \fB\-\-verbose\fR
  96 Print pid(s) that will be signaled with kill along with the signal.
  97 .TP
  98 \fB\-q\fR, \fB\-\-queue\fR \fIvalue\fR
  99 Use
 100 .BR sigqueue (2)
 101 rather than
 102 .BR kill (2).
 103 The
 104 .I value
 105 argument is an integer that is sent along with the signal.  If the
 106 receiving process has installed a handler for this signal using the SA_SIGINFO
 107 flag to
 108 .BR sigaction (2),
 109 then it can obtain this data via the si_sigval field of the siginfo_t structure.
 110
 111 .SH NOTES
 112 It is not possible to send a signal to an explicitly selected thread in a
 113 multithreaded process using the
 114 .BR kill (2)
 115 syscall.  If
 116 .BR kill (2)
 117 is used to send a signal to a thread group, then the kernel selects an arbitrary
 118 member of the thread group that has not blocked the signal.  For more details
 119 see
 120 .BR clone (2),
 121 the CLONE_THREAD description.
 122 .PP
 123 The command
 124 .BR kill (1)
 125 as well as syscall
 126 .BR kill (2)
 127 accept a TID (thread ID, see
 128 .BR gettid (2))
 129 as an argument.  In this case the kill behavior is not changed and the signal is
 130 also delivered to the thread group rather than to the specified thread.
 131
 132 .SH RETURN CODES
 133 .B kill
 134 has the following return codes:
 135 .TP
 136 .BR 0
 137 success
 138 .TP
 139 .BR 1
 140 failure
 141 .TP
 142 .BR 64
 143 partial success (when more than one process specified)
 144
 145 .SH SEE ALSO
 146 .BR bash (1),
 147 .BR tcsh (1),
 148 .BR sigvec (2),
 149 .BR kill (2),
 150 .BR signal (7)
 151
 152 .SH AUTHORS
 153 .MT svalente@mit.edu
 154 Salvatore Valente
 155 .ME
 156 .br
 157 .MT kzak@redhat.com
 158 Karel Zak
 159 .ME
 160 .br
 161 .PP
 162 The original version was taken from BSD 4.4.
 163
 164 .SH AVAILABILITY
 165 The kill command is part of the util-linux package and is available from
 166 .UR ftp://\:ftp.kernel.org\:/pub\:/linux\:/utils\:/util-linux/
 167 Linux Kernel Archive
 168 .UE .