Expose real operating system process IDs on Windows via os_display_pid()

os/mingw.c

@@ -3157,6 +3157,15 @@ pid_t os_spawn(char** argv, int* stdout_read_int, int* stderr_read_int, const ch
 	return (intptr_t)pi.hProcess;
 }
 
+uint64_t os_display_pid(pid_t pid)
+{
+	if (pid <= 0)
+		return 0;
+
+	HANDLE h = (void*)pid;
+	return (uint64_t)GetProcessId(h);
+}
+
 pid_t os_wait(pid_t pid, int* status)
 {
 	HANDLE h = (void*)pid;

os/os.h

@@ -121,10 +121,19 @@ int os_pclose(OS_FILE* stream);
  * \param stdout_read_fd Pointer to store file descriptor for stdout, or NULL to redirect to /dev/null.
  * \param stderr_read_fd Pointer to store file descriptor for stderr, or NULL to redirect to /dev/null.
  * \param run_as_user User to run script as (NULL for current user).
- * \return Process ID of spawned process, or -1 on failure.
+ * \return Process reference of spawned process, or -1 on failure.
  */
 pid_t os_spawn(char** argv, int* stdout_read_fd, int* stderr_read_fd, const char* run_as_user);
 
+/**
+ * Get the operating system process ID suitable for display.
+ * On Unix the process reference is already the PID.
+ * On Windows the process reference is a HANDLE and the actual PID is obtained with GetProcessId().
+ * \param pid Process reference returned by os_spawn().
+ * \return Operating system process ID, or 0 if unavailable.
+ */
+uint64_t os_display_pid(pid_t pid);
+
 /**
  * Wait for the child process to terminate.
  * This function does not release the process reference returned by os_spawn().

os/unix.c

@@ -1507,6 +1507,14 @@ pid_t os_spawn(char** argv, int* stdout_read_fd, int* stderr_read_fd, const char
 	return pid;
 }
 
+uint64_t os_display_pid(pid_t pid)
+{
+	if (pid <= 0)
+		return 0;
+
+	return (uint64_t)pid;
+}
+
 pid_t os_wait(pid_t pid, int* status)
 {
 	pid_t ret;