I can't find the console for Node-RED.
Do I have to use Node-RED Runtime API's RED.log()? Some Node-RED frontends, like FRED, seem to have a console. Also here a console is mentioned.
Is there a console accessible on the shell, or do I have to use the debug-Node?
Thanks in advance
Peter
Node-RED outputs data to the terminal it is started on.
So if you start it manually on the command line with node-red or node red it will print to the terminal.
If you've installed Node-RED as a service so it is launched at startup then it will depend on what platform you are on as to where the console log will end up. On Linux then there is a fair chance that it will end up in the journal and can be tailed with the following command:
sudo journalctl -f -u nodered -o cat
If you're running Node-RED on Bluemix then the you can see the console with the cf command line too:
cf logs <app-name>
or you can see it in the Bluemix web console.
As for sending data to this output then you have a few of options.
The Debug node has an option to output to the console, this is useful when the msg object (or msg.payload) is too big to fit in the debug side bar.
When writing your own nodes then you can use RED.log, This will add a time stamp and a node id to the output which can be useful when debugging.
At a pinch you can use console.log, but this will just dump things to standard out with no formatting or time stamp
Related
I am very new to coding, and have just installed VS Code, and installed Node.js as well as Git Bash. I was working on a project, but couldn't console.log anything as I always received the following error when using Git Bash:
bash: syntax error near unexpected token `validateCred' (One of the
variables I used)
I created a new JS file, and ran the following code:
const hello = 'hello world';
I still received the same bash error. I have tried replacing my code with code that I know works and still receive the same errors.I have also tried using Powershell as my terminal, but receive the following errors every time:
batch : The term 'batch' is not recognized as the name of a cmdlet,
function, script file, or operable program. Check the spelling of the
name, or if a path was included, verify that the path is correct and
try again.
I am at a loss, and I'm sure it's something really simple, but I can't seem to figure it out!
A Bash shell expects you to enter Bash code and not JavaScript code.
If you want to run JavaScript code then you need to run it in Node.js and not in Bash.
Generally, the command node will launch Node.js in a Bash shell. (Assuming it is installed on the $PATH).
I am trying to console log a piece of JavaScript code through Node.Js but the terminal is not showing any output.
const pokemon = require('pokemon');
pokemon.all();
var name = pokemon.random();
console.log(name);
Can't even console log a simple line of code
console.log("Hello");
Image of terminal after executing node file
It is possible that you use node which is not a nodejs package but another. If you type node on command line, do you see something like this? Especially the message Welcome to Node.js vxx.xx.x.
hanania#laptop:~$ node
Welcome to Node.js v12.16.3.
Type ".help" for more information.
>
just try to check out if nodejs is installed successfully on your device by runing
node --version
and if it doesn't respond with nodejs version you need to reinstall nodejs
I have just recently started learning about APIs as party of Full stack developer course. Everything has been working fine until I have activated system storage sense in Windows to clear some space in the disk /c, the curl command stopped working and is giving internal server error.
curl calling request error using bash terminal
I have realized there is an issue when I have run my code and it stopped pulling information from the API link.
Since you made a windows change my guess would be - try addding the curl folder path to your Windows PATH environment variable so that the curl command is available from any location at the command prompt.
I am trying to debug my backend and i am not really sure if i am doing it the correct way.
I have set up the debugging as follows:
Node 6.9.1 and node-inspector 0.12.8
open a command prompt and run the following command:
node-inspector --web-port=3030 (server app port)
open another command prompt and run the following command:
node --inspect --debug-brk server.js
browse to the given URL in the second command prompt log on screen
press F8 to make the server run
eventually put some others breakpoints
browse on another tab to your app (address and port defined in 1-)
see server execution stops on breakpoints defined on step 5.
Now when i run node --inspect app.js and everything looks good so far. I can debug the first start in the app.js. But if I want to debug an endpoint with POSTMAN, I get the error "Cannot POST /api/trainingsWeek". The endpoint works if I don't debug.
Do I have to take another address? Or another tool than POSTMAN?
ANd what is the difference between node --inspect app.js and node-debug
GitHub Issue
UPDATE
This was my stupid mistake :P Here is the solution: https://github.com/node-inspector/node-inspector/issues/907#issuecomment-280620108
I use VS Code to debug. I guess you don't need node-inspector, it will run with the integrated debugger from Node. To get it running, open your project and the debug view. There should be no configuration available. Click on the little wheel -> choose node.js as the environment.
After that the standard json will be created and looks like this:
And then click on the play button with the selection start programm. With that the debugging should run. Now you can use POSTMAN with the same url when you just run your server and the debugger from VS Code should hit your breakpoint.
I am interested in writing a web based terminal which can execute and autocomplete the commands in ubuntu terminal.
I have fiddled with Anyterm http://www.anyterm.org which uses ROTE: "a simple C library for VT102 terminal emulation" at the backend server and javascript/html for the terminal ui. The problem was that I couldn't have it open two terminals in the same window.
After doing some research I've decided to write a terminal server/pseudo terminal (whichever is the right terminology) in python which can:
execute commands in ubuntu terminal (such as ls, grep etc...)
autocomplete the commands (like $gedi (pressed tab) $gedit)
and have multiple instances of terminal open at the same time (when typed ls in one, the other terminal won't recognize ls as the last command since its another terminal session)
I have found that with pty python module I can write a pseudo terminal
however I'm new to python and I couldn't even get the example on that page to work.
I'm planning to have the python script serve a http server with the javascript/html terminal ui I would write (this was the main reason I wanted to choose python for this project). Then I want to let the web ui talk to the backend terminal "server" and get the results back to the web ui.
If you could point me in the right direction, maybe tell me which module I should use -if not pty- and give me some ideas on how to write the python pseudo terminal server I would appreciate it.
I know javascript/php and familiar with bash scripting- At this point I could go for a C based or python based backend server, is python right for this project?
Note: I'm planning to write a ui that uses ajax post or get methods to retrieve the terminal output from backend server.
You need to learn the basic terminology first. The shell is the program that interprets your input command lines, such as grep "foo" abc.txt. A terminal emulator is a program that mimics a terminal. Terminal is a device with display and keyboard that one
used in 1970s to access a UNIX mainframe. A pseudoterminal, pty is the device node supporting terminal emulators, as opposed to "real terminal devices" (tty1) for example.
Now, you could either build a shell, that would work in terminal instead of bash or dash; or you could build a terminal emulator that is usable over the internet; you could run any existing shell in it. Both are challenging tasks by themselves.
Python documentation is not of much use, I recommend you should start by googling more of these concepts first - and not only python references, but C, C++ too.
And lastly, if you want to run Emacs or nano or some other advanced program in your shell, you want to use the pty module.
I had a friends who did something similar but he did it over Google chat, I don't know how much help it will be but take a look at xmpp (python modual) maybe it could help you, or even here is a link to his source code:
chatIO
I didn't work with him on it but it was really easy for him to use
Good Luck