Changes in uspace/lib/c/generic/str.c [8e893ae:1772e6d] in mainline

File:

• uspace/lib/c/generic/str.c (modified) (5 diffs)

uspace/lib/c/generic/str.c

@@ -428 +428 @@
  *
  * Do a char-by-char comparison of two NULL-terminated strings.
- * The strings are considered equal iff they consist of the same
- * characters on the minimum of their lengths.
+ * The strings are considered equal iff their length is equal
+ * and both strings consist of the same sequence of characters.
+ *
+ * A string S1 is less than another string S2 if it has a character with
+ * lower value at the first character position where the strings differ.
+ * If the strings differ in length, the shorter one is treated as if
+ * padded by characters with a value of zero.
  *
  * @param s1 First string to compare.
  * @param s2 Second string to compare.
  *
- * @return 0 if the strings are equal, -1 if first is smaller,
- *         1 if second smaller.
+ * @return 0 if the strings are equal, -1 if the first is less than the second,
+ *         1 if the second is less than the first.
  *
  */
@@ -466 +471 @@
  *
  * Do a char-by-char comparison of two NULL-terminated strings.
- * The strings are considered equal iff they consist of the same
- * characters on the minimum of their lengths and the length limit.
+ * The strings are considered equal iff
+ * min(str_length(s1), max_len) == min(str_length(s2), max_len)
+ * and both strings consist of the same sequence of characters,
+ * up to max_len characters.
+ *
+ * A string S1 is less than another string S2 if it has a character with
+ * lower value at the first character position where the strings differ.
+ * If the strings differ in length, the shorter one is treated as if
+ * padded by characters with a value of zero. Only the first max_len
+ * characters are considered.
  *
  * @param s1      First string to compare.
@@ -473 +486 @@
  * @param max_len Maximum number of characters to consider.
  *
- * @return 0 if the strings are equal, -1 if first is smaller,
- *         1 if second smaller.
+ * @return 0 if the strings are equal, -1 if the first is less than the second,
+ *         1 if the second is less than the first.
  *
  */
@@ -508 +521 @@
         return 0;
 
+}
+
+/** Test whether p is a prefix of s.
+ *
+ * Do a char-by-char comparison of two NULL-terminated strings
+ * and determine if p is a prefix of s.
+ *
+ * @param s The string in which to look
+ * @param p The string to check if it is a prefix of s
+ *
+ * @return true iff p is prefix of s else false
+ *
+ */
+bool str_test_prefix(const char *s, const char *p)
+{
+        wchar_t c1 = 0;
+        wchar_t c2 = 0;
+        
+        size_t off1 = 0;
+        size_t off2 = 0;
+
+        while (true) {
+                c1 = str_decode(s, &off1, STR_NO_LIMIT);
+                c2 = str_decode(p, &off2, STR_NO_LIMIT);
+                
+                if (c2 == 0)
+                        return true;
+
+                if (c1 != c2)
+                        return false;
+                
+                if (c1 == 0)
+                        break;
+        }
+
+        return false;
 }
 
@@ -1085 +1134 @@
                 c = (c >= 'a' ? c - 'a' + 10 : (c >= 'A' ? c - 'A' + 10 :
                     (c <= '9' ? c - '0' : 0xff)));
-                if (c > base) {
+                if (c >= base) {
                         break;
                 }