easiest way to create a tarball with a file called seahorse.txt with the contents and attributes of a file called file.txt

tarball-rewrite-file-paths.js

//@ts-check

// easiest way to create a tarball with a file called seahorse.txt 
// with the contents and attributes of a file called file.txt

let Header = require('tar/lib/header')
let ReadEntry = require('tar/lib/read-entry')
let Pack = require('tar/lib/pack.js')
let modeFix = require('tar/lib/mode-fix')
let fs = require('fs')


// target file name
let path = __dirname+'/file.txt'
// get the stat
let stat = fs.statSync(path)
// change the stat into a header and make a read entry form the header
let entry = pathToReadEntry({path,toPath:'/seahorse.txt',stat})
// create a new Pack
let pack = new Pack({gzip:false})

// write the entry
pack.write(entry)

// when the entry is done end the pack.
entry.on('end',()=>{
    pack.end()
})

// write it to a file.
pack.pipe(fs.createWriteStream('./test.tar'))



function pathToReadEntry(opts){
    const {path,toPath,linkpath,stat} = opts

    let myuid = process.getuid && process.getuid()
    let myuser = process.env.USER || ''

    // settings. 
    //override mtime.
    let mtime = false;
    // dont write an mtime
    let noMtime = true;
    // dont write anything other than size, linkpath, path and mode
    let portable = true;

    let header = new Header({
        path: toPath || path,
        // if this is a link. the path the link points to.
        linkpath: linkpath,
        mode: modeFix(stat.mode,stat.isDirectory()),
        uid: portable ? null : stat.uid,
        gid: portable ? null : stat.gid,
        size: stat.size,
        mtime: noMtime ? null : mtime || stat.mtime,
        type: statToType(stat),
        uname: portable ? null :
        stat.uid === myuid ? myuser : '',
        atime: portable ? null : stat.atime,
        ctime: portable ? null : stat.ctime
    })

    let entry = new ReadEntry(header)
    fs.createReadStream(path).pipe(entry)

    return entry
}



function statToType(stat){
    if(stat.isDirectory()) return 'Directory'
    if(stat.isSymbolicLink()) return 'SymbolicLink'
    if(stat.isFile()) return 'File'
    // return nothing if unsupported.
}