What's with this strange number Xel?... Well, this is a very useful number to help you determine how a remote system, or your network, is presenting numeric values.
When we program, we generally stick to one system or one platform at a time, however, life is never always so vanilla, and we've had a problem in the office today of talking to a raw network connection from a remote system. We didn't know anything about this remote system, through a combination of lingual differences and a total lack of documentation (SNAFU).
So, we didn't know what endianess the remote processor was treating numbers as, and we also didn't know if the network was doing conversion between endian settings.
Apparently someone else had puzzled over this for a few weeks before giving up.
I however, channelled the power of the number 252117761.
What's so special about this number?... Well, it's a 32bit number, so we have four 8 bit bytes in there, and it's binary pattern is:
00001111000001110000001100000001
If you can't see the use of this pattern already in checking your networking and endieness, then you might have a problem.
It helps you check out the received values back, if you know you assign a value on one side as this integer, and we call for it across the link, we can see whether we get the above, or a change of order:
00000001000000110000011100001111
For example was the return we had, which is a change or ordering.
But you can also see whether you get:
00000011000000010000111100000111
Which is a short reordering.
Why 32 bit?... Well in this case, because we did know that the word size of the remote system was 32bits, but you can use this trick with any number of bits, just total up your values...
111111101111111001111110001111100001111000001110000001100000001
Might be a good 64bit pattern, and has the value 9187131167487755009.
