1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.8 $ -->
<!-- splitted from ./en/functions/pcntl.xml, last change in rev 1.1 -->
<refentry id="function.pcntl-waitpid">
<refnamediv>
<refname>pcntl_waitpid</refname>
<refpurpose>Waits on or returns the status of a forked child</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<methodsynopsis>
<type>int</type><methodname>pcntl_waitpid</methodname>
<methodparam><type>int</type><parameter>pid</parameter></methodparam>
<methodparam><type>int</type><parameter role="reference">status</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter>options</parameter></methodparam>
</methodsynopsis>
<para>
The <function>pcntl_waitpid</function> function suspends execution
of the current process until a child as specified by the
<parameter>pid</parameter> argument has exited, or until a signal
is delivered whose action is to terminate the current process or
to call a signal handling function. If a child as requested by
<parameter>pid</parameter> has already exited by the time of the
call (a so-called "zombie" process), the function returns
immediately. Any system resources used by the child are
freed. Please see your system's waitpid(2) man page for specific
details as to how waitpid works on your system.
</para>
<para>
<function>pcntl_waitpid</function> returns the process ID of the
child which exited, -1 on error or zero if WNOHANG was used and no
child was available
</para>
<para>
The value of <parameter>pid</parameter> can be one of the following:
<table>
<title>possible values for <parameter>pid</parameter></title>
<tgroup cols="2">
<tbody>
<row>
<entry><literal>< -1</literal></entry>
<entry>
wait for any child process whose process group ID is equal to
the absolute value of <parameter>pid</parameter>.
</entry>
</row>
<row>
<entry><literal>-1</literal></entry>
<entry>
wait for any child process; this is the same behaviour that
the wait function exhibits.
</entry>
</row>
<row>
<entry><literal>0</literal></entry>
<entry>
wait for any child process whose process group ID is equal to
that of the calling process.
</entry>
</row>
<row>
<entry><literal>> 0</literal></entry>
<entry>
wait for the child whose process ID is equal to the value of
<parameter>pid</parameter>.
</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<note>
<para>
Specifying <literal>-1</literal> as the <parameter>pid</parameter> is
equivalent to the functionality <function>pcntl_wait</function> provides
(minus <parameter>options</parameter>).
</para>
</note>
<para>
<function>pcntl_waitpid</function> will store status information
in the <parameter>status</parameter> parameter which can be
evaluated using the following functions:
<function>pcntl_wifexited</function>,
<function>pcntl_wifstopped</function>,
<function>pcntl_wifsignaled</function>,
<function>pcntl_wexitstatus</function>,
<function>pcntl_wtermsig</function> and
<function>pcntl_wstopsig</function>.
</para>
<para>
The value of <parameter>options</parameter> is the value of zero
or more of the following two global constants
<literal>OR</literal>'ed together:
<table>
<title>possible values for <parameter>options</parameter></title>
<tgroup cols="2">
<tbody>
<row>
<entry><literal>WNOHANG</literal></entry>
<entry>
return immediately if no child has exited.
</entry>
</row>
<row>
<entry><literal>WUNTRACED</literal></entry>
<entry>
return for children which are stopped, and whose status has
not been reported.
</entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<para>
See also <function>pcntl_fork</function>,
<function>pcntl_signal</function>,
<function>pcntl_wifexited</function>,
<function>pcntl_wifstopped</function>,
<function>pcntl_wifsignaled</function>,
<function>pcntl_wexitstatus</function>,
<function>pcntl_wtermsig</function> and
<function>pcntl_wstopsig</function>.
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"../../../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
|
