Index: fusl/src/string/strverscmp.c |
diff --git a/fusl/src/string/strverscmp.c b/fusl/src/string/strverscmp.c |
new file mode 100644 |
index 0000000000000000000000000000000000000000..4daf276d0cfeb0725649141b8a16a52f89794710 |
--- /dev/null |
+++ b/fusl/src/string/strverscmp.c |
@@ -0,0 +1,34 @@ |
+#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]!='0' && r[dp]!='0') { |
+ /* If we're not looking at a digit sequence that began |
+ * with a zero, 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]; |
+} |