Add RMUtil_StringConvert

rmutil/strings.c

@@ -2,6 +2,7 @@
 #include <sys/param.h>
 #include <ctype.h>
 #include "strings.h"
+#include "alloc.h"
 
 #include "sds.h"
 
@@ -68,3 +69,13 @@ void RMUtil_StringToUpper(RedisModuleString *s) {
     ++c;
   }
 }
+
+void RMUtil_StringConvert(RedisModuleString **rs, const char **ss, size_t n, int options) {
+  for (size_t ii = 0; ii < n; ++ii) {
+    const char *p = RedisModule_StringPtrLen(rs[ii], NULL);
+    if (options & RMUTIL_STRINGCONVERT_COPY) {
+      p = strdup(p);
+    }
+    ss[ii] = p;
+  }
+}

rmutil/strings.h

@@ -25,4 +25,14 @@ void RMUtil_StringToLower(RedisModuleString *s);
 
 /* Converts a redis string to uppercase in place without reallocating anything */
 void RMUtil_StringToUpper(RedisModuleString *s);
+
+// If set, copy the strings using strdup rather than simply storing pointers.
+#define RMUTIL_STRINGCONVERT_COPY 1
+
+/**
+ * Convert one or more RedisModuleString objects into `const char*`.
+ * Both rs and ss are arrays, and should be of <n> length.
+ * Options may be 0 or `RMUTIL_STRINGCONVERT_COPY`
+ */
+void RMUtil_StringConvert(RedisModuleString **rs, const char **ss, size_t n, int options);
 #endif