os/process: add pid()

include/hyprutils/os/Process.hpp

@@ -3,6 +3,7 @@
 #include <string>
 #include <vector>
 #include <utility>
+#include <sys/types.h>
 
 namespace Hyprutils {
     namespace OS {
@@ -23,10 +24,14 @@ namespace Hyprutils {
             const std::string& stdOut();
             const std::string& stdErr();
 
+            // only populated when ran async
+            const pid_t pid();
+
           private:
             std::string                                      binary, out, err;
             std::vector<std::string>                         args;
             std::vector<std::pair<std::string, std::string>> env;
+            pid_t                                            grandchildPid = 0;
         };
     }
 }

src/os/Process.cpp

@@ -209,7 +209,9 @@ bool Hyprutils::OS::CProcess::runAsync() {
     read(socket[0], &grandchild, sizeof(grandchild));
     close(socket[0]);
     // clear child and leave grandchild to init
-    waitpid(child, NULL, 0);
+    waitpid(child, nullptr, 0);
+
+    grandchildPid = grandchild;
 
     return true;
 }
@@ -220,4 +222,8 @@ const std::string& Hyprutils::OS::CProcess::stdOut() {
 
 const std::string& Hyprutils::OS::CProcess::stdErr() {
     return err;
-}
+}
+
+const pid_t Hyprutils::OS::CProcess::pid() {
+    return grandchildPid;
+}

tests/os.cpp

@@ -1,3 +1,7 @@
+#include <csignal>
+#include <cerrno>
+#include <cstdlib>
+#include <unistd.h>
 #include <hyprutils/os/Process.hpp>
 #include "shared.hpp"
 
@@ -15,5 +19,12 @@ int main(int argc, char** argv, char** envp) {
     EXPECT(process.stdOut(), std::string{"Hello World!\n"});
     EXPECT(process.stdErr(), std::string{""});
 
+    CProcess process2("sh", {"-c", "while true; do sleep 1; done;"});
+
+    EXPECT(process2.runAsync(), true);
+    EXPECT(getpgid(process2.pid()) >= 0, true);
+
+    kill(process2.pid(), SIGKILL);
+
     return ret;
 }