40 lines
969 B
C
40 lines
969 B
C
/* memcmp -- compare two memory regions.
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This function is in the public domain. */
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/*
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@deftypefn Supplemental int memcmp (const void *@var{x}, const void *@var{y}, size_t @var{count})
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Compares the first @var{count} bytes of two areas of memory. Returns
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zero if they are the same, a value less than zero if @var{x} is
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lexically less than @var{y}, or a value greater than zero if @var{x}
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is lexically greater than @var{y}. Note that lexical order is determined
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as if comparing unsigned char arrays.
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@end deftypefn
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*/
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#include <ansidecl.h>
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#ifdef __STDC__
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#include <stddef.h>
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#else
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#define size_t unsigned long
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#endif
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int
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DEFUN(memcmp, (str1, str2, count),
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const PTR str1 AND const PTR str2 AND size_t count)
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{
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register const unsigned char *s1 = (const unsigned char*)str1;
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register const unsigned char *s2 = (const unsigned char*)str2;
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while (count-- > 0)
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{
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if (*s1++ != *s2++)
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return s1[-1] < s2[-1] ? -1 : 1;
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}
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return 0;
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}
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