Since PL/I programming languages have technique for handling exceptional situations. Most famous is the setjmp/longjmp in C language. Here is an example, how it is working.

#include <setjmp.h>
#include <stdio.h>

jmp_buf x;

void f()
{
    longjmp(x,5);
}

int main()
{
    int i = 0;

    if ( (i = setjmp(x)) == 0 )
    {
        f();
    }
    else
    {
        switch( i )
        {
        case  1:
        case  2:
        default: fprintf( stdout, "error code = %d\n", i); break;
        }
    }
    return 0;
}