launch_daemon: Replace fork+exec with posix_spawn.

src/servers/launch/BaseJob.cpp

@@ -7,10 +7,12 @@
 #include "BaseJob.h"
 
 #include <errno.h>
+#include <spawn.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
+#include <AutoDeleter.h>
 #include <Message.h>
 
 #include "Conditions.h"
@@ -201,25 +203,38 @@ BaseJob::_GetSourceFileEnvironment(const char* script, BStringList& environment)
 		return;
 	}
 
-	pid_t child = fork();
-	if (child < 0) {
+	posix_spawn_file_actions_t fileActions;
+	int status = posix_spawn_file_actions_init(&fileActions);
+	if (status != 0) {
 		// TODO: log error
-		debug_printf("could not fork: %s\n", strerror(errno));
-	} else if (child == 0) {
-		// We're the child, redirect stdout
-		close(STDOUT_FILENO);
-		close(STDERR_FILENO);
-		dup2(pipes[1], STDOUT_FILENO);
-		dup2(pipes[1], STDERR_FILENO);
+		return;
+	}
+	CObjectDeleter<posix_spawn_file_actions_t, int, posix_spawn_file_actions_destroy>
+		actionsDeleter(&fileActions);
+
+	// redirect stdout in the child
+	posix_spawn_file_actions_addclose(&fileActions, STDOUT_FILENO);
+	posix_spawn_file_actions_addclose(&fileActions, STDERR_FILENO);
+	posix_spawn_file_actions_adddup2(&fileActions, pipes[1], STDOUT_FILENO);
+	posix_spawn_file_actions_adddup2(&fileActions, pipes[1], STDERR_FILENO);
 
 	for (int32 i = 0; i < 2; i++)
-			close(pipes[i]);
+		posix_spawn_file_actions_addclose(&fileActions, pipes[i]);
 
 	BString command;
 	command.SetToFormat(". \"%s\"; export -p", script);
-		execl("/bin/sh", "/bin/sh", "-c", command.String(), NULL);
-		exit(1);
-	} else {
+
+	const char* argv[] = {"/bin/sh", "-c", command.String(), NULL};
+
+	pid_t child;
+	status = posix_spawn(&child, argv[0], &fileActions, NULL, (char**)argv, NULL);
+
+	if (status != 0) {
+		// TODO: log error
+		debug_printf("could not fork: %s\n", strerror(errno));
+		return;
+	}
+
 	// Retrieve environment from child
 
 	close(pipes[1]);
@@ -252,7 +267,6 @@ BaseJob::_GetSourceFileEnvironment(const char* script, BStringList& environment)
 		_ParseExportVariable(environment, line);
 
 	close(pipes[0]);
-	}
 }