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gdaemon_unix.cpp
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1//
2// Copyright (C) 2001-2021 Graeme Walker <graeme_walker@users.sourceforge.net>
3//
4// This program is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// This program is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with this program. If not, see <http://www.gnu.org/licenses/>.
16// ===
17///
18/// \file gdaemon_unix.cpp
19///
20
21#include "gdef.h"
22#include "gdaemon.h"
23#include "gprocess.h"
24#include "gnewprocess.h"
25
26 void G::Daemon::detach( PidFile & pid_file )
27{
28 pid_file.check() ; // absolute path
29 detach() ;
30}
31
32 void G::Daemon::detach()
33{
34 // see Stevens, ISBN 0-201-563137-7, ch 13.
35
36 if( !NewProcess::fork().first )
37 std::_Exit( 0 ) ; // exit from parent
38
39 setsid() ;
40 Process::cd( "/" , std::nothrow ) ;
41
42 if( !NewProcess::fork().first )
43 std::_Exit( 0 ) ; // exit from parent
44}
45
46 void G::Daemon::setsid()
47{
48 GDEF_IGNORE_RETURN ::setsid() ;
49}
50
G::Daemon::detach
static void detach()
Detaches from the parent environment.
Definition: gdaemon_unix.cpp:32
G::NewProcess::fork
static std::pair< bool, pid_t > fork()
A utility function that forks the calling process and returns twice; once in the parent and once in t...
Definition: gnewprocess_unix.cpp:129
G::PidFile
A class for creating pid files.
Definition: gpidfile.h:57
G::PidFile::check
void check()
Throws an exception if the path is not absolute.
Definition: gpidfile.cpp:126
G::Process::cd
static void cd(const Path &dir)
Changes directory.
Definition: gprocess_unix.cpp:69
gdaemon.h
gnewprocess.h
gprocess.h