_wspawnl/_spawnl equivalent on Mac OS X or Linux - c++

Question

I am just porting a code to Mac OS X which is using _tspawnl on Windows.
Is there anything equivalent to _tspawnl on Mac OS X or Linux?
Or is there any posix equivalent to _tspawnl

Answer 1

You can use fork and execv system call together in the following way :
if (!fork()){ // create the new process
execl(path, *arg, ...); // execute the new program
}
The fork system call creates a new process, while the execv system call starts the execution of the application specify in path.
For example, you can use the following function spawn whose argument are the name of the application to be executed and the list of its arguments.
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>
int spawn (char* program, char** arg_list)
{
pid_t child_pid;
/* Duplicate this process. */
child_pid = fork ();
if (child_pid != 0)
/* This is the parent process. */
return child_pid;
else {
/* Now execute PROGRAM, searching for it in the path. */
execvp (program, arg_list);
/* The execvp function returns only if an error occurs. */
fprintf (stderr, “an error occurred in execvp\n”);
abort ();
}
}
int main ()
{
/* The argument list to pass to the “ls” command. */
char* arg_list[] = {
“ls”, /* argv[0], the name of the program. */
“-l”,
“/”,
NULL /* The argument list must end with a NULL. */
};
spawn (“ls”, arg_list);
printf (“done with main program\n”);
return 0;
}
This example has been taken from the chapter 3.2.2 of this book. (Really good reference for development in Linux).

Answer 2

You can use fork()/exec(), as already pointed out, however a closer system call is posix_spawn() (manpage).
It can be a bit of a pain to set-up, however, but there is some example code using it is here (note that this code also provides functionality for Windows using the CreateProcess() API, which is probably what you should be using under Windows anyway).