| 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]; | |
| } | |