     https://cocalc.com/api/v1/project_exec
   ==> {"event":"project_exec_output",
        "id":"39289ba7-0333-48ad-984e-b25c8b8ffa0e",
-       "stdout":"xyz abc\n",
+       "stdout":"xyz abc\\n",
        "stderr":"",
        "exit_code":0}
 ```

    https://cocalc.com/api/v1/project_exec
  ==> {"event":"project_exec_output",
       "id":"8a78a37d-b2fb-4e29-94ae-d66acdeac949",
       "stdout":"/projects/e49e86aa-192f-410b-8269-4b89fd934fba/Private\n","stderr":"","exit_code":0}
```

Command line arguments specified by 'args' option. Note JSON format for request parameters.

    https://cocalc.com/api/v1/public_get_text_file
  ==> {"event":"public_text_file_contents",
       "id":"2d0e2faa-893a-44c1-9f64-59203bbbb017",
       "data":"hello world\\nToday is Friday\\n"}
```

Attempt to read a file which is not public.
