#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <sys/ptrace.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/user.h>
#include <sys/reg.h>
#include <sys/syscall.h>
#include <unistd.h>

int main()
{

    struct user data;

    pid_t child;
    child = fork();
    long sys = -2;
    if(child == 0) {
        ptrace(PTRACE_TRACEME, 0, NULL, NULL);
        execl("/bin/ls", "ls", NULL);
    }
    else while (sys != 60 and sys != -1)
    {
        if (sys == -2)
            wait(NULL);
        // Get syscall:
        if (ptrace(PTRACE_SYSCALL,child, NULL ,NULL) == -1)
            fprintf(stderr,"Syscall failed: %s\n", strerror(errno));
        wait(NULL);
        // Check syscall:
        sys = ptrace(PTRACE_PEEKUSER,child, ((long long)&data.regs.orig_rax - (long long)&data), NULL);
        if (sys == -1)
            fprintf(stderr,"Syscall failed: %s\n", strerror(errno));
        else
            fprintf(stderr,"Syscall called: %d\n",(int)sys);
    }
    return 0;
}