// make sure that bins are executable, and that they don't have // windows line-endings on the hashbang line. const { chmod, open, readFile, } = require('fs/promises') const execMode = 0o777 & (~process.umask()) const writeFileAtomic = require('write-file-atomic') const isWindowsHashBang = buf => buf[0] === '#'.charCodeAt(0) && buf[1] === '!'.charCodeAt(0) && /^#![^\n]+\r\n/.test(buf.toString()) const isWindowsHashbangFile = file => { const FALSE = () => false return open(file, 'r').then(fh => { const buf = Buffer.alloc(2048) return fh.read(buf, 0, 2048, 0) .then( () => { const isWHB = isWindowsHashBang(buf) return fh.close().then(() => isWHB, () => isWHB) }, // don't leak FD if read() fails () => fh.close().then(FALSE, FALSE) ) }, FALSE) } const dos2Unix = file => readFile(file, 'utf8').then(content => writeFileAtomic(file, content.replace(/^(#![^\n]+)\r\n/, '$1\n'))) const fixBin = (file, mode = execMode) => chmod(file, mode) .then(() => isWindowsHashbangFile(file)) .then(isWHB => isWHB ? dos2Unix(file) : null) module.exports = fixBin