command-exists

What is command-exists?

The command-exists npm package is used to check if a given command is available in the system's PATH. It is useful for Node.js applications that need to ensure certain commands are installed before attempting to execute them.

What are command-exists's main functionalities?

Synchronous check

This feature allows you to synchronously check if a command exists in the system's PATH.

const commandExistsSync = require('command-exists').sync;

if (commandExistsSync('git')) {
  console.log('Git exists!');
} else {
  console.log('Git does not exist.');
}

Asynchronous check

This feature allows you to asynchronously check if a command exists in the system's PATH.

const commandExists = require('command-exists');

commandExists('git', function(err, commandExists) {
  if(commandExists) {
    console.log('Git exists!');
  } else {
    console.log('Git does not exist.');
  }
});

Promise-based check

This feature provides a promise-based interface to check if a command exists, which can be used with modern async/await syntax.

const commandExists = require('command-exists');

commandExists('git')
  .then(function(command) {
    console.log('Git exists!');
  }).catch(function() {
    console.log('Git does not exist.');
  });

Other packages similar to command-exists

which

The 'which' package is similar to 'command-exists' as it checks for the existence of a command. It is a Node.js implementation of the Unix 'which' command. It differs in that it provides the path to the executable if it exists, rather than just a boolean indicating existence.

lookpath

The 'lookpath' package is another alternative that checks if a command exists in the system's PATH. It is similar to 'command-exists' but returns the full path of the command if it exists. It also supports Windows and is designed to be a lightweight solution.

shelljs

While 'shelljs' is a more comprehensive shell scripting utility library, it includes a 'which' method that can be used to check for the existence of commands, similar to 'command-exists'. It provides additional shell-related functionalities beyond command checking.

README

command-exists

node module to check if a command-line command exists

installation

npm install command-exists

usage

async

var commandExists = require('command-exists');

commandExists('ls', function(err, commandExists) {

    if(commandExists) {
        // proceed confidently knowing this command is available
    }

});

promise

var commandExists = require('command-exists');

// invoked without a callback, it returns a promise
commandExists('ls')
.then(function(command){
    // proceed
}).catch(function(){
    // command doesn't exist
});

sync

var commandExistsSync = require('command-exists').sync;
// returns true/false; doesn't throw
if (commandExistsSync('ls')) {
    // proceed
} else {
    // ...
}

changelog

v1.2.0

Add support for promises

v1.1.0

Add synchronous version

v1.0.2

Support for windows