Summury Of Article

How to get arguments when executing from the command line in javascript (nodejs), with sample code. I'm recording this as a reminder.

This is useful, for example, when running javascript as a batch program using npm run. No external libraries are used, so you can just copy and paste the code.

My Environment

How to pass arguments from the command line

You can pass arguments from shell or command-line like this.

This is the same as the normal way of passing arguments from shell (Windows command line passing to batch).

> node sample1.js arg1test arg2test samplearg3

Now you can pass the three arguments "arg1test", "arg2test", and "samplearg3" to the "sample1.js" javascript .

To pass a string containing spaces as a single argument, enclose it in double quotation marks as shown below.

> node sample1.js "arg1-1 arg1-2" "arg2-1 arg2-2"

Now we can pass the two strings "arg1-1 arg1-2" and "arg2-1 arg2-2" as arguments to sample1.js at runtime, respectively.

Argument calls from nodejs scripts

Let's prepare the following sample.js.

console.log(process.argv);

OK. Let's pass three arguments to this script.

> node sample.js "arg1-1 arg1-2" arg2 arg3
[
  'C:\\Program Files2\nodejs\\node.exe',
  'C:\\02_data\01_dev\03_nodachisoftweb\\nodachisoft_www\\\batch\ sample.js',
  'arg1-1 arg1-2',
  'arg2',
  'arg3'.
]

You can refer to the arguments passed from the command line in process.argv.

The contents of process.argv are as follows

Specifically, the array of arguments passed to sample.js can be obtained as follows.

var argsStr = process.argv.slice(2);
var count = 0;
argsStr.forEach(arg=>{console.log(`arg[${count++}]=${arg}`)});

Try to run it with passing 3 arguments.

> node sample.js "arg1-1 arg1-2" arg2 "arg3-1 arg3-2" 
arg[0]=arg1-1 arg1-2
arg[1]=arg2
arg[2]=arg3-1 arg3-2

We can now check the contents of each of the purely passed arguments.

Websites and references that were very helpful.

• How to parse command line arguments

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