1// Copyright (c) 2025-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#include <util/exec.h>
6
7#include <util/fs.h>
8#ifdef WIN32
9#include <util/subprocess.h>
10#endif
11
12#include <cstdlib>
13#include <string>
14#include <system_error>
15
16#ifdef WIN32
17#include <process.h>
18#include <windows.h>
19#else
20#include <unistd.h>
21#endif
22
23namespace util {
24int ExecVp(const char* file, char* const argv[])
25{
26#ifndef WIN32
27    return execvp(file, argv);
28#else
29    std::vector<std::string> escaped_args;
30    for (char* const* arg_ptr{argv}; *arg_ptr; ++arg_ptr) {
31        subprocess::util::quote_argument(std::string{*arg_ptr}, escaped_args.emplace_back(), /*force=*/false);
32    }
33
34    std::vector<const char*> new_argv;
35    new_argv.reserve(escaped_args.size() + 1);
36    for (const auto& s : escaped_args) new_argv.push_back(s.c_str());
37    new_argv.push_back(nullptr);
38    return _execvp(file, new_argv.data());
39#endif
40}
41
42fs::path GetExePath(std::string_view argv0)
43{
44    // Try to figure out where executable is located. This does a simplified
45    // search that won't work perfectly on every platform and doesn't need to,
46    // as it is only currently being used in a convenience wrapper binary to try
47    // to prioritize locally built or installed executables over system
48    // executables.
49    const fs::path argv0_path{fs::PathFromString(std::string{argv0})};
50    fs::path path{argv0_path};
51    std::error_code ec;
52#ifndef WIN32
53    // If argv0 doesn't contain a path separator, it was invoked from the system
54    // PATH and can be searched for there.
55    if (!argv0_path.has_parent_path()) {
56        if (const char* path_env = std::getenv("PATH")) {
57            size_t start{0}, end{0};
58            for (std::string_view paths{path_env}; end != std::string_view::npos; start = end + 1) {
59                end = paths.find(':', start);
60                fs::path candidate = fs::path(paths.substr(start, end - start)) / argv0_path;
61                if (fs::is_regular_file(candidate, ec)) {
62                    path = candidate;
63                    break;
64                }
65            }
66        }
67    }
68#else
69    wchar_t module_path[MAX_PATH];
70    if (GetModuleFileNameW(nullptr, module_path, MAX_PATH) > 0) {
71        path = fs::path{module_path};
72    }
73#endif
74    return path;
75}
76
77} // namespace util
78