1 .\" Copyright (c) 1996 The NetBSD Foundation, Inc.
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5 .\" by Paul Kranenburg.
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28 .\" $NetBSD: psignal.9,v 1.1 1996/06/22 22:57:35 pk Exp $
38 .Nd post signal to a process or process group
43 .Fn psignal "struct proc *p" "int signum"
45 .Fn pgsignal "struct pgrp *pgrp" "int signum" "int checkctty"
47 .Fn gsignal "int pgid" "int signum"
49 These functions post a signal to one or more processes.
52 common to all three functions should be in the range
57 function posts signal number
59 to the process represented by the process structure
61 With a few exceptions noted below, the target process signal disposition is
62 updated and is marked as runnable, so further handling of the signal is done
63 in the context of the target process after a context switch.
66 does not by itself cause a context switch to happen.
68 The target process is not marked as runnable in the following cases:
69 .Bl -bullet -offset indent
71 The target process is sleeping uninterruptibly.
73 noticed when the process returns from the system call or trap.
75 The target process is currently ignoring the signal.
77 If a stop signal is sent to a sleeping process that takes the
81 the process is stopped without awakening it.
84 restarts a stopped process
85 (or puts them back to sleep)
86 regardless of the signal action
87 (e.g., blocked or ignored).
90 If the target process is being traced
92 behaves as if the target process were taking the default action for
94 This allows the tracing process to be notified of the signal.
98 function posts signal number
100 to each member of the process group described by
104 is non-zero, the signal will be posted only to processes that have
105 a controlling terminal.
107 is implemented by walking along the process list headed by the field
109 of the process group structure
123 function posts signal number
125 to each member of the process group identified by the group id
128 first finds the group structure associated with
137 is zero no action is taken.