1 files changed, 45 insertions, 0 deletions
diff --git a/common/alstring.cpp b/common/alstring.cpp
new file mode 100644
index 00000000..4a84be1d
--- /dev/null
+++ b/common/alstring.cpp
@@ -0,0 +1,45 @@
+
+#include "config.h"
+
+#include "alstring.h"
+
+#include <cctype>
+#include <string>
+
+
+namespace {
+
+int to_upper(const char ch)
+{
+    using char8_traits = std::char_traits<char>;
+    return std::toupper(char8_traits::to_int_type(ch));
+}
+
+} // namespace
+
+namespace al {
+
+int strcasecmp(const char *str0, const char *str1) noexcept
+{
+    do {
+        const int diff{to_upper(*str0) - to_upper(*str1)};
+        if(diff < 0) return -1;
+        if(diff > 0) return 1;
+    } while(*(str0++) && *(str1++));
+    return 0;
+}
+
+int strncasecmp(const char *str0, const char *str1, std::size_t len) noexcept
+{
+    if(len > 0)
+    {
+        do {
+            const int diff{to_upper(*str0) - to_upper(*str1)};
+            if(diff < 0) return -1;
+            if(diff > 0) return 1;
+        } while(--len && *(str0++) && *(str1++));
+    }
+    return 0;
+}
+
+} // namespace al