sds.c: new function sdsjoin() to join strings.

src/sds.c

@@ -621,6 +621,19 @@ sds sdsmapchars(sds s, const char *from, const char *to, size_t setlen) {
     return s;
 }
 
+/* Join an array of C strings using the specified separator (also a C string).
+ * Returns the result as an sds string. */
+sds sdsjoin(char **argv, int argc, char *sep) {
+    sds join = sdsempty();
+    int j;
+
+    for (j = 0; j < argc; j++) {
+        join = sdscat(join, argv[j]);
+        if (j != argc-1) join = sdscat(join,sep);
+    }
+    return join;
+}
+
 #ifdef SDS_TEST_MAIN
 #include <stdio.h>
 #include "testhelp.h"