htons.md

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Function name : htons

Group: Windows Sockets 2 (Winsock) - Library: ws2_32

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The htons function converts a u_short from host to TCP/IP network byte order (which is big-endian).

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Code examples:

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Declaration:

u_short htons(
  u_short hostshort
);  

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FoxPro declaration:

DECLARE INTEGER htons IN ws2_32;
	INTEGER hostshort  

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Parameters:

hostshort [in] 16-bit number in host byte order.

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Return value:

The htons function returns the value in TCP/IP network byte order.

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Hints:

On newer Windows Systems htons sets bits after the 15th bit. Example:

? htons(465)

This returns on 32bit Systems the Value 53505, on 64bit Systems on newer Windows Version it returns 119041. When converting to binary it is clear, that the 16th bit is set:

01101000100000001 -> 53505
11101000100000001 -> 119041

Other values have other bits set. This causes some code to fail when the num2word function is used:

FUNCTION num2word(lnValue)
RETURN Chr(MOD(m.lnValue,256)) + CHR(INT(m.lnValue/256))

To resolve this, ignore everything after the 15th bit:

=num2word(BITAND(htons(587),65535))

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