If i use %c in format string then command return NULL reply.
Example command (SET Test:1 a):
reply = redisCommand(conn,"SET Test:1 %s", "a"); // this work (Command OK)
reply = redisCommand(conn,"SET Test:1 a"); // this work (Command OK)
reply = redisCommand(conn,"SET Test:1 %c", 'a'); // this d'nt work (reply == NULL)
reply = redisCommand(conn,"SET T%cst:1 a", 'e'); // this d'nt work (reply == NULL)

This problem also exists in redisAppendCommand, redisvAppendCommand and etc