Nodejs: Exec from child_process returns bin/sh: 1: command not found but works when writing manually in terminal?

Question

Using Node.js to automatically execute command in the terminal on raspberry pi, tho it wont work with exec(command). It outputs bin/sh: 1: command not found when trying to catch the output. But the command works when writing the command manually in the terminal?

Why is that?

async function run_command_fuel() {
    const command = "weconnect-cli PASSWORDINFORMATION get /vehicles/SECRETNUM/domains/fuelStatus/rangeStatus/primaryEngine/remainingRange_km";
   
    let returnval = 0;

    let child = exec(command);


    await new Promise((resolve, reject) => {
        child.stdout.on('data', function(data) {
            console.log('stdout: ' + data);
            returnval = data;
            console.log(returnval);
            resolve();
        });
        child.stderr.on('data', function(data) {
            console.log('stderr: ' + data);
            reject();
        });
        child.on('close', function(code) {
            console.log('closing code: ' + code);
        });
    })

    return returnval;

}

Answer 1

Running the exec command creates a new shell, which wont have the same environment as your node process. You will need to specify the PATH environment variable in order to use that command.

Node gives you a way to do this through the object you pass in the exec command, as the second parameter, which defaults to process.env .

To pass in the object:

const command = "weconnect-cli PASSWORDINFORMATION get /vehicles/SECRETNUM/domains/fuelStatus/rangeStatus/primaryEngine/remainingRange_km";

let child = exec(command, {env: {'PATH': 'path/to/command'}});

Another way you can do this is through standard shell env setting before a command. You can modify your command to this:

const env_vars = 'PATH=' + 'path/to/command' + ' ';
const command = "weconnect-cli PASSWORDINFORMATION get /vehicles/SECRETNUM/domains/fuelStatus/rangeStatus/primaryEngine/remainingRange_km";

let child = exec(env_vars + command);