CODEWITHSUNDEEP
javascriptcommand-line-argumentsargv
ssarahhhhhh
ssarahhhhhh

Reputation: 27

Command Line Index

I am sending the following text through the command line and not sure how to extract the different names in the -q tag command: -s 127.0.0.1:3000 -q test1.pdf test2.pdf test3.pdf test4.pdf-v 7

The number of file names being sent in can change

This is how I am currently parsing through
var s = process.argv.indexOf('-s') + 1;let files = process.argv.indexOf('-q') + 1; let version = process.argv.indexOf('-v') + 1;

let fileName = process.argv[files ].split(' ')

Any recommendations on what to try?

Upvotes: 1

Views: 145

Answers (2)

Jerren Saunders
Jerren Saunders

Reputation: 1435

Normally for command line arguments, if each test*.pdf file was supposed to belong to the -q option, I would expect to see them listed as either:

-q "test1.pdf,test2.pdf,test3.pdf,test4.pdf"

or

-q test1.pdf -q test2.pdf -q test3.pdf -q test4.pdf

Both of these styles will make the logic much easier to parse in addition to being a more conventional style.

Also, I would suggest you look into the yargs module (https://yargs.js.org/) for parsing arguments.

Update: If the input can't be changed, then I'd suggest working through the list of args and if it starts with a '-' char, remember that option and continue to collect all consecutive options into that array until you reach another flag.

Some rough code:

const opts = {}; // Hold all options
const optionPattern = /^(?<Prefix>-{1,2}|\/)(?<Flag>.*)/; // Support various styles: -s, --s, /s
let currFlag = 'Unknown'; // Bucket to hold any args not specifically marked

for (const elem of process.argv) {
    const matchResult = optionPattern.exec(elem);
    if (matchResult) {
        currFlag = matchResult.groups.Flag;
    } else {
        opts[currFlag] = opts[currFlag] || []; // Create the array if this is the first one
        opts[currFlag].push(elem);
    }
}

console.log(`Options Received: ${JSON.stringify(opts, null, 4)}`);

The above would output:

Options Received: {
"Unknown": [
    "C:\\Program Files\\nodejs\\node.exe",
    "C:\\Projects\\NodeTestScripting\\TestScripts\\CommandLineArgs.js"
],
"s": [
    "127.0.0.1:3000"
],
"q": [
    "test1.pdf",
    "test2.pdf",
    "test3.pdf",
    "test4.pdf"
],
"v": [
    "7"
]

}

Upvotes: 1

BiOS
BiOS

Reputation: 2304

You could implement this vary basic solution, iterating through the arguments and picking those which contain ".pdf" in them.

for (i of process.argv) {
    if (i.includes(".pdf")) {
        //i is your filename now, do something with it
        console.log(i);
    }
}

Differently, if you don't only have one type of file extension, you could apply a closer solution to what you were already guessing, assuming that the file-names are always contained within the -q and -v flags:

let fIdx = process.argv.indexOf('-q'); 
let vIdx = process.argv.indexOf('-v'); 

for (i of process.argv.slice(fIdx+1,vIdx)) {
    //i is your filename now, do something with it
    console.log(i)
}

Upvotes: 1

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