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Search path without new allocations.

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At least not for searching. The final result still requires allocating
a string for the final result, but no longer for the intermediates.
This commit is contained in:
Bert Peters
2018-03-25 20:35:31 +02:00
parent 55156959d4
commit 6456ab0612
1 changed files with 20 additions and 14 deletions
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34
src/tools/launcher.cpp
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@@ -5,11 +5,16 @@
bool executable_exists(std::string_view dir, std::string_view executable)
{
std::string executable_path(dir);
executable_path += '/';
executable_path += executable;
if (dir.size() + executable.size() + 1 >= PATH_MAX) {
std::cerr << "Error: requested path longer than PATH_MAX" << std::endl;
return false;
}
char path_buf[PATH_MAX] = {'\0'};
std::copy(dir.begin(), dir.end(), path_buf);
path_buf[dir.size()] = '/';
std::copy(executable.begin(), executable.end(), &path_buf[dir.size() + 1]);
return access(executable_path.c_str(), F_OK | X_OK) == 0;
return access(path_buf, F_OK | X_OK) == 0;
}
class Launcher : public Gtk::Window {
@@ -144,16 +149,17 @@ void Launcher::findExecutable()
return;
}
const char* env_path = std::getenv("PATH");
if (env_path == nullptr || env_path[0] == '\0') {
return;
}
std::unique_ptr<char[]> buffer(new char[std::strlen(env_path) + 1]);
std::strcpy(buffer.get(), env_path);
for (auto component = std::strtok(buffer.get(), ":"); component; component = std::strtok(nullptr, ":")) {
if (executable_exists(component, "fmri")) {
std::string_view env_path = std::getenv("PATH");
std::string_view::size_type offset = 0;
while (offset != std::string_view::npos) {
auto limit = env_path.find(":");
auto component = env_path.substr(offset, limit);
if (limit != std::string_view::npos) {
offset = limit + 1;
} else {
offset = limit;
}
if (!component.empty() && executable_exists(component, "fmri")) {
fmriChooser.set_filename(std::string(component) + "/fmri");
return;
}