add string comparison functions

rmutil/util.c

@@ -6,6 +6,7 @@
 #include <stdarg.h>
 #include <limits.h>
 #include <string.h>
+#include <strings.h>
 #include <redismodule.h>
 #include "util.h"
 
@@ -40,7 +41,7 @@ int RMUtil_ArgIndex(const char *arg, RedisModuleString **argv, int argc) {
     if (l != larg) continue;
     if (carg != NULL && strncasecmp(carg, arg, larg) == 0) {
       return offset;
-    }
+    } \
   }
   return -1;
 }
@@ -246,3 +247,16 @@ int RedisModule_TryGetValue(RedisModuleKey *key, const RedisModuleType *type, vo
     return RMUTIL_VALUE_MISMATCH;
   }
 }
+
+int RedisModule_Strncasecmp(const RedisModuleString *rs1, const char *s2, size_t n) {
+  size_t n2;
+  const char *s1 = RedisModule_StringPtrLen(rs1, &n2);
+  if (n != n2) {
+    return -1;
+  }
+  return strncasecmp(s1, s2, n);
+}
+
+int RedisModule_Strcasecmp(const RedisModuleString *s1, const char *s2) {
+  return RedisModule_Strncasecmp(s1, s2, strlen(s2));
+}

rmutil/util.h

@@ -130,4 +130,19 @@ typedef enum {
  */
 int RedisModule_TryGetValue(RedisModuleKey *key, const RedisModuleType *type, void **out);
 
+/**
+ * Compares a RedisModuleString against an actual string buffer, avoiding
+ * keeping a temporary value for RedisModule_StringPtrLen.
+ * @param s1 the RedisModuleString
+ * @param s2 the buffer
+ * @param n the length of the C string.
+ * Returns 0 if the strings are equal.
+ */
+int RedisModule_Strncasecmp(const RedisModuleString *s1, const char *s2, size_t n);
+
+/**
+ * Exactly like RedisModule_Strncasecmp, except that `s2` is NUL-terminated
+ */
+int RedisModule_Strcasecmp(const RedisModuleString *s, const char *s2);
+
 #endif