use sys.stdout.isatty() to detect if a tty is available

otherworld

@@ -80,8 +80,9 @@ def docker_create_user (container, user, uid=None):
 def docker_start (container):
     call(["docker", "start", container])
 
-def docker_exec (container, command, user, env={}, work_dir=None):
-    call(["docker", "exec", "--user", user, "-ti"] + \
+def docker_exec (container, command, user, env={}, tty=True, work_dir=None):
+    call(["docker", "exec", "--user", user] + \
+         (["-ti" if tty else "-i"]) + \
          (["--workdir", work_dir] if work_dir else []) + \
          list(chain.from_iterable([["--env", f"{kv[0]}={kv[1]}"] for kv in env.items()])) + \
          [container] + command)
@@ -131,13 +132,14 @@ def expand_user_volumes (volumes):
 
     return mappings
 
-def find_config_files (config_name):
+def find_config_files (config_names):
     config_files = []
     directory = os.path.abspath(os.getcwd())
     while True:
-        config_file = os.path.join(directory, config_name)
-        if os.path.exists(config_file):
-            config_files.append(config_file)
+        for config_name in config_names:
+            config_file = os.path.join(directory, config_name)
+            if os.path.exists(config_file):
+                config_files.append(config_file)
         
         if directory == "/" or (not directory):
             break
@@ -174,6 +176,7 @@ command_env = {}
 command_workdir = None
 
 quiet = False
+tty = sys.stdout.isatty()
 
 # load config from files
 config = load_config_files({
@@ -188,8 +191,9 @@ config = load_config_files({
     "user_volumes": user_volumes,
     "pull": pull,
     "command_env": command_env,
-    "cwd": os.getcwd()
-}, find_config_files(OTHERWORLD_CONFIG))
+    "cwd": os.getcwd(),
+    "tty": tty
+}, find_config_files([OTHERWORLD_CONFIG, "{}{}".format(container_name, OTHERWORLD_CONFIG)]))
 locals().update(config)
 
 while len(command) > 0:
@@ -197,6 +201,9 @@ while len(command) > 0:
     if arg == "--quiet":
         command = command[1:]
         quiet = True
+    elif arg == "--notty":
+        command = command[1:]
+        tty = False
     elif arg == "--rm":
         actions.append("rm")
         command = command[1:]
@@ -313,4 +320,4 @@ except Exception:
 
 if not quiet:
     print(f">> Welcome to {container_name} (IP {container['NetworkSettings']['IPAddress']})")
-docker_exec(container_name, command, command_user, command_env, command_workdir)
+docker_exec(container_name, command, command_user, command_env, tty, command_workdir)