run batch file in npm script

Anna Morning picture Anna Morning · May 9, 2018 · Viewed 14k times · Source

Is it possible and how to run a batch script in npm command?

I have an angular project, in package.json file, under scripts section, I want to define a npm command to run batch script. I know I can run shell script with keyword bash e.g.

"start": "cd mydir && bash ./myscript"

Then I can run npm start in my project directory, which will change directory and execute myscript.sh script. What is the equivalent keyword to run batch script in npm?

Newbie here. Sorry if this is a duplicate question; maybe I'm not search the correct terms, but I can't see to find answers to this question.

Answer

RobC picture RobC · May 16, 2018

To help provide context to this answer, let's say we two batch files named say-hello.bat and say-hello-cmd. Both batch files have the same simple contrived content as follows:

echo Hello World

When invoking either of the two batch files via npm-scripts, we expect the console to log:

Hello World

Project Directory Structure:

Now, let's assume our project directory is structured as follows:

.
├── a
│   └── b
│       ├── say-hello.bat
│       └── say-hello.cmd
├── package.json
├── say-hello.bat
├── say-hello.cmd
└── ...

As you can see, we have:

  • say-hello.bat and say-hello.cmd stored in the root of the project directory. They're at the same level as package.json.
  • We also have say-hello.bat and say-hello.cmd stored in a sub directory of the project directory The path to these is: a/b/

npm-scripts

To be able to invoke these batch files via npm, the scripts section of package.json should be defined something like the following:

{
  ...
  "scripts": {
    "bat": "say-hello.bat",
    "cmd": "say-hello.cmd",
    "bat-in-sub-dir": "cd a/b/ && say-hello.bat",
    "cmd-in-sub-dir": "cd a/b/ && say-hello.cmd"
  },
  ...
}

If you now cd to your project directory and run any of the following commands:

  • npm run bat
  • npm run cmd
  • npm run bat-in-sub-dir
  • npm run cmd-in-sub-dir

The batch file(s) will be run and you will successfully see the words Hello World logged to the console.

Notes

The notable difference between these examples above is:

  • When the batch file is stored in the root of your projects directory you just provide the name of the batch file in your script. E.g.

    "bat": "say-hello.bat"
    
  • When the batch file is stored in a sub directory of your project directory (e.g. a/b/) you have to firstly cd to that folder, and then provide the name of the batch file to run. E.g.

    "bat-in-sub-dir": "cd a/b/ && say-hello.bat"