#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

enum
{
    EXIT_CODE = 128
};

int
mysys(const char *str)
{
    int pid;
    if ((pid = fork()) < 0) {
        return -1;
    } else if (!pid) {
        execlp("bin/sh", "sh", "-c", str, NULL);
        _exit(EXIT_CODE - 1);
    } else {
        int sg;
        waitpid(pid, &sg, 0);
        _Bool fl = sg == EXIT_CODE - 1;
        if (fl) {
            return sg;
        }
        fl = WIFSIGNALED(sg) != 0;
        if (fl) {
            return sg + EXIT_CODE;
        }
        return WEXITSTATUS(sg);
    }
}