35 lines
973 B
C
35 lines
973 B
C
#define _GNU_SOURCE
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#include <ctype.h>
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#include <string.h>
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int strverscmp(const char *l0, const char *r0)
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{
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const unsigned char *l = (const void *)l0;
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const unsigned char *r = (const void *)r0;
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size_t i, dp, j;
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int z = 1;
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/* Find maximal matching prefix and track its maximal digit
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* suffix and whether those digits are all zeros. */
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for (dp=i=0; l[i]==r[i]; i++) {
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int c = l[i];
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if (!c) return 0;
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if (!isdigit(c)) dp=i+1, z=1;
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else if (c!='0') z=0;
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}
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if (l[dp]!='0' && r[dp]!='0') {
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/* If we're not looking at a digit sequence that began
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* with a zero, longest digit string is greater. */
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for (j=i; isdigit(l[j]); j++)
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if (!isdigit(r[j])) return 1;
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if (isdigit(r[j])) return -1;
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} else if (z && dp<i && (isdigit(l[i]) || isdigit(r[i]))) {
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/* Otherwise, if common prefix of digit sequence is
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* all zeros, digits order less than non-digits. */
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return (unsigned char)(l[i]-'0') - (unsigned char)(r[i]-'0');
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}
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return l[i] - r[i];
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}
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