basic: add new ascii_strcasecmp_n() call

3 files changed, 45 insertions, 0 deletions

diff --git a/src/basic/string-util.c b/src/basic/string-util.c
index 849e457439..b7b8c97bc0 100644
--- a/src/basic/string-util.c
+++ b/src/basic/string-util.c
@@ -348,6 +348,21 @@ char *ascii_strlower_n(char *t, size_t n) {
         return t;
 }
 
+int ascii_strcasecmp_n(const char *a, const char *b, size_t n) {
+
+        for (; n > 0; a++, b++, n--) {
+                int x, y;
+
+                x = (int) (uint8_t) ascii_tolower(*a);
+                y = (int) (uint8_t) ascii_tolower(*b);
+
+                if (x != y)
+                        return x - y;
+        }
+
+        return 0;
+}
+
 bool chars_intersect(const char *a, const char *b) {
         const char *p;
 
diff --git a/src/basic/string-util.h b/src/basic/string-util.h
index 1ac6bcd6f8..6374e11119 100644
--- a/src/basic/string-util.h
+++ b/src/basic/string-util.h
@@ -134,6 +134,8 @@ char ascii_tolower(char x);
 char *ascii_strlower(char *s);
 char *ascii_strlower_n(char *s, size_t n);
 
+int ascii_strcasecmp_n(const char *a, const char *b, size_t n);
+
 bool chars_intersect(const char *a, const char *b) _pure_;
 
 static inline bool _pure_ in_charset(const char *s, const char* charset) {
diff --git a/src/test/test-string-util.c b/src/test/test-string-util.c
index 25444c794a..4758108706 100644
--- a/src/test/test-string-util.c
+++ b/src/test/test-string-util.c
@@ -55,7 +55,35 @@ static void test_string_erase(void) {
         assert_se(streq(string_erase(x), "xxxxxxxxx"));
 }
 
+static void test_ascii_strcasecmp_n(void) {
+
+        assert_se(ascii_strcasecmp_n("", "", 0) == 0);
+        assert_se(ascii_strcasecmp_n("", "", 1) == 0);
+        assert_se(ascii_strcasecmp_n("", "a", 1) < 0);
+        assert_se(ascii_strcasecmp_n("", "a", 2) < 0);
+        assert_se(ascii_strcasecmp_n("a", "", 1) > 0);
+        assert_se(ascii_strcasecmp_n("a", "", 2) > 0);
+        assert_se(ascii_strcasecmp_n("a", "a", 1) == 0);
+        assert_se(ascii_strcasecmp_n("a", "a", 2) == 0);
+        assert_se(ascii_strcasecmp_n("a", "b", 1) < 0);
+        assert_se(ascii_strcasecmp_n("a", "b", 2) < 0);
+        assert_se(ascii_strcasecmp_n("b", "a", 1) > 0);
+        assert_se(ascii_strcasecmp_n("b", "a", 2) > 0);
+        assert_se(ascii_strcasecmp_n("xxxxyxxxx", "xxxxYxxxx", 9) == 0);
+        assert_se(ascii_strcasecmp_n("xxxxxxxxx", "xxxxyxxxx", 9) < 0);
+        assert_se(ascii_strcasecmp_n("xxxxXxxxx", "xxxxyxxxx", 9) < 0);
+        assert_se(ascii_strcasecmp_n("xxxxxxxxx", "xxxxYxxxx", 9) < 0);
+        assert_se(ascii_strcasecmp_n("xxxxXxxxx", "xxxxYxxxx", 9) < 0);
+
+        assert_se(ascii_strcasecmp_n("xxxxYxxxx", "xxxxYxxxx", 9) == 0);
+        assert_se(ascii_strcasecmp_n("xxxxyxxxx", "xxxxxxxxx", 9) > 0);
+        assert_se(ascii_strcasecmp_n("xxxxyxxxx", "xxxxXxxxx", 9) > 0);
+        assert_se(ascii_strcasecmp_n("xxxxYxxxx", "xxxxxxxxx", 9) > 0);
+        assert_se(ascii_strcasecmp_n("xxxxYxxxx", "xxxxXxxxx", 9) > 0);
+}
+
 int main(int argc, char *argv[]) {
         test_string_erase();
+        test_ascii_strcasecmp_n();
         return 0;
 }