[완료] Linux System Call clone() 에 관하여.

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sched.h>
 
int variable, fd;
 
int do_something() {
        variable = 42;
        close(fd);
        _exit(0);
}
 
int main(int argc, char *argv[]) {
        void **child_stack;
        char tempch; 
        int ret = 0;
 
        variable = 9;
        fd = open("test.file", O_RDONLY);
        child_stack = (void **) malloc(16384);
        printf("The variable was %d\n", variable);
 
        ret = clone(do_something, child_stack, CLONE_VM|CLONE_FILES, NULL);
        if (ret < 0) {
                perror("clone");
        }       
        sleep(1);
 
        printf("The variable is now %d\n", variable);
        if (read(fd, &tempch, 1) < 1) {
                perror("File Read Error");
                exit(1);
        }       
        printf("We could read from the file\n");
        return 0;
}

[root@mach2 tmp]# gcc -o test_clone test_clone.c -Wall
[root@mach2 tmp]# ./test_clone                        
The variable was 9
Killed