the system call number

[Zheng Da]

Hello,

I try to trace all system calls in a period of time, and then print
out all system calls and the invokers.
How do I get the system call number, or better the names of the system calls?
I tried $syscall, but it doesn't work.

probe syscall.* {
        if ($syscall != 4) {
                curr_time = gettimeofday_us()
                        if (curr_time > start_time + 1000000 * 3)
                                printf ("%s calls %d\n", execname(), $syscall)
        }
}

Thanks,
Da