| #define _GNU_SOURCE |
| #include <ctype.h> |
| #include <string.h> |
| |
| int strverscmp(const char *l0, const char *r0) |
| { |
| const unsigned char *l = (const void *)l0; |
| const unsigned char *r = (const void *)r0; |
| size_t i, dp, j; |
| int z = 1; |
| |
| /* Find maximal matching prefix and track its maximal digit |
| * suffix and whether those digits are all zeros. */ |
| for (dp=i=0; l[i]==r[i]; i++) { |
| int c = l[i]; |
| if (!c) return 0; |
| if (!isdigit(c)) dp=i+1, z=1; |
| else if (c!='0') z=0; |
| } |
| |
| if (l[dp]-'1'<9U && r[dp]-'1'<9U) { |
| /* If we're looking at non-degenerate digit sequences starting |
| * with nonzero digits, longest digit string is greater. */ |
| for (j=i; isdigit(l[j]); j++) |
| if (!isdigit(r[j])) return 1; |
| if (isdigit(r[j])) return -1; |
| } else if (z && dp<i && (isdigit(l[i]) || isdigit(r[i]))) { |
| /* Otherwise, if common prefix of digit sequence is |
| * all zeros, digits order less than non-digits. */ |
| return (unsigned char)(l[i]-'0') - (unsigned char)(r[i]-'0'); |
| } |
| |
| return l[i] - r[i]; |
| } |