exec for running shell commands in Node.js - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to import the exec function from the child_process module.

Node.js

const { [1] } = require('child_process');

Drag options to blanks, or click blank then click option'

Afork

Bspawn

Cexec

DexecFile

Attempts:

3 left

💡 Hint

Common Mistakes

Using spawn instead of exec

Trying to import the whole module without destructuring

Using execFile which is different

The exec function is imported from the child_process module to run shell commands.

2fill in blank

medium

Complete the code to run the shell command 'ls -l' using exec.

Node.js

exec('[1]', (error, stdout, stderr) => {
  if (error) {
    console.error(`Error: ${error.message}`);
    return;
  }
  console.log(stdout);
});

Drag options to blanks, or click blank then click option'

Aecho Hello

Bls -l

Cpwd

Ddir

Attempts:

3 left

💡 Hint

Common Mistakes

Using Windows command 'dir' on Unix

Using 'pwd' which shows current directory only

Using 'echo Hello' which just prints text

The command ls -l lists files in long format on Unix-like systems.

3fill in blank

hard

Fix the error in the callback parameters to correctly handle exec output.

Node.js

exec('node -v', ([1]) => {
  if (error) {
    console.error(error);
    return;
  }
  console.log(stdout);
});

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Aerror, stdout, stderr

Berr, output

Cerror

Dresult

Attempts:

3 left

💡 Hint

Common Mistakes

Using only one parameter and missing stdout

Using wrong parameter names

Not handling stderr

The callback for exec receives three parameters: error, stdout, and stderr.

4fill in blank

hard

Fill both blanks to run 'echo Hello' and print the output or error.

Node.js

exec('[1]', (error, [2], stderr) => {
  if (error) {
    console.error(`Error: ${error.message}`);
    return;
  }
  console.log([2]);
});

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Aecho Hello

Bstdout

Coutput

Dls

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong command

Using wrong variable name for output

Ignoring error handling

The command is echo Hello and the output is in stdout.

5fill in blank

hard

Fill all three blanks to run 'cat file.txt', handle errors, and print output.

Node.js

exec('[1]', ([2], [3], stderr) => {
  if ([2]) {
    console.error(`Error: $[2].message}`);
    return;
  }
  console.log([3]);
});

Drag options to blanks, or click blank then click option'

Acat file.txt

Berror

Cstdout

Dinput

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong command like 'ls' instead of 'cat'

Mixing up error and output parameters

Not checking for error before printing output

The command cat file.txt reads the file content. The callback parameters are error and stdout for output.