Converting a numerical char array to a long?

[jlou]

How about:

unsigned char x[3];        // unsigned char is a 8-bit value on 8051 
x[0] = 0x02;
x[1] = 0xFF;
x[2] = 0xFF;

unsigned long i = 0;
for (int index = 0; index < 3; index++)
{
    i <<= 8;
    i |= x[index];
}

// or

unsigned long i = x[0];
i = i << 8;
i = i | x[1];
i = i << 8;
i = i | x[2];