# Control Flow

This part is really simple, if you have some basic knowledge about any programming language.

I would like to give two examples here, and for more information you could refer to [Ref 1](https://sourceware.org/systemtap/man/stap.1.html).

## if condition

```
probe begin
{ 
    if (pid())
        printf("%d:%s\n", pid(), execname());
    else
        printf("invalid pid\n");
    exit();
}
```

## for loop

```
probe begin
{ 
    index = 0;
    for (; index < 10; index++)
        arr[index] = index;
    exit();
}
```