skarg
50 lines
1.6 KiB
C
50 lines
1.6 KiB
C
/* Derived from "Unix Incompatibility Notes: Byte Order" by Jan Wolter */
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/* http://unixpapa.com/incnote/byteorder.html */
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/** @file bigend.c Determination of Endianess */
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#include "bigend.h"
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/* Big-Endian systems save the most significant byte first. */
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/* Sun and Motorola processors, IBM-370s and PDP-10s are big-endian. */
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/* "Network Byte Order" is also know as "Big-Endian Byte Order" */
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/* for example, a 4 byte integer 67305985 is 0x04030201 in hexidecimal. */
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/* x[0] = 0x04 */
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/* x[1] = 0x03 */
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/* x[2] = 0x02 */
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/* x[3] = 0x01 */
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/* Little-Endian systems save the least significant byte first. */
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/* The entire Intel x86 family, Vaxes, Alphas and PDP-11s are little-endian. */
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/* for example, a 4 byte integer 67305985 is 0x04030201 in hexidecimal. */
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/* x[0] = 0x01 */
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/* x[1] = 0x02 */
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/* x[2] = 0x03 */
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/* x[3] = 0x04 */
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/* Note: Endianness doesn't apply to all variable manipulation.
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If you use bitwise or bitshift operations on integers,
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you can avoid having to check for endianness. */
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/* The names are derived from Jonathon Swift's book Gulliver's Travels,
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where they describe Lilliputian political parties who disagree
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vehemently over which end to start eating an egg from.
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This terminology was popularized for byte order by a less than
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completely serious paper authored by Danny Cohen which appeared
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on April 1, 1980 and was entitled "On Holy Wars and a Plea for Peace" */
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/* function to return true on Big-Endian architectures */
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/* (based on Harbison & Steele) */
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int big_endian(
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void)
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{
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union {
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long l;
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char c[sizeof(long)];
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} u;
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u.l = 1;
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return (u.c[sizeof(long) - 1] == 1);
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}
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