process-cpp  3.0.0
A simple convenience library for handling processes in C++11.
exec.cpp
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1 /*
2  * Copyright © 2013 Canonical Ltd.
3  *
4  * This program is free software: you can redistribute it and/or modify it
5  * under the terms of the GNU Lesser General Public License version 3,
6  * as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11  * GNU Lesser General Public License for more details.
12  *
13  * You should have received a copy of the GNU Lesser General Public License
14  * along with this program. If not, see <http://www.gnu.org/licenses/>.
15  *
16  * Authored by: Thomas Voß <thomas.voss@canonical.com>
17  */
18 
19 #include <core/posix/exec.h>
20 #include <core/posix/fork.h>
22 
23 #include <iostream>
24 
25 #include <cstring>
26 
27 #include <unistd.h>
28 
29 namespace core
30 {
31 namespace posix
32 {
33 ChildProcess exec(const std::string& fn,
34  const std::vector<std::string>& argv,
35  const std::map<std::string, std::string>& env,
36  const StandardStream& flags)
37 {
38  std::function<void()> null_function = [](){};
39  return exec(fn, argv, env, flags, null_function);
40 }
41 
42 ChildProcess exec(const std::string& fn,
43  const std::vector<std::string>& argv,
44  const std::map<std::string, std::string>& env,
45  const StandardStream& flags,
46  const std::function<void()>& child_setup)
47 {
48  return posix::fork([fn, argv, env, child_setup]()
49  {
50  char** it; char** pargv; char** penv;
51  it = pargv = new char*[argv.size()+2];
52  *it = ::strdup(fn.c_str());
53  it++;
54  for (auto element : argv)
55  {
56  *it = ::strdup(element.c_str());
57  it++;
58  }
59  *it = nullptr;
60 
61  it = penv = new char*[env.size()+1];
62  for (auto pair : env)
63  {
64  *it = ::strdup((pair.first + "=" + pair.second).c_str());
65  it++;
66  }
67  *it = nullptr;
68 
69  child_setup();
70  return static_cast<posix::exit::Status>(execve(fn.c_str(), pargv, penv));
71  }, flags);
72 }
73 
74 }
75 }
Status
The Status enum wrap&#39;s the posix exit status.
Definition: exit.h:33
StandardStream
The StandardStream enum wraps the POSIX standard streams.
CORE_POSIX_DLL_PUBLIC ChildProcess fork(const std::function< posix::exit::Status()> &main, const StandardStream &flags)
fork forks a new process and executes the provided main function in the newly forked process...
Definition: fork.cpp:57
CORE_POSIX_DLL_PUBLIC ChildProcess exec(const std::string &fn, const std::vector< std::string > &argv, const std::map< std::string, std::string > &env, const StandardStream &flags)
exec execve&#39;s the executable with the provided arguments and environment.
Definition: exec.cpp:33
The Process class models a child process of this process.
Definition: child_process.h:43