Package Exports
- fs-lotus
This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (fs-lotus) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.
Readme
fs-lotus
Sugar to open and close a file descriptor.
usage
const open = require('fs-lotus')
, fs = require('fs')
const readExactly = function (filename, pos, length, done) {
open(filename, 'r', function (err, fd, close) {
if (err) return done(err)
fs.read(fd, Buffer(length), 0, length, pos, function (err, bytesRead, buf) {
if (err) return close(done, err)
if (bytesRead !== length) {
return close(done, new Error('End of file'))
}
close(done, null, buf)
})
})
}The open function has the same signature as fs.open(path, flags[, mode], callback). Except that callback also receives a close(callback, err, ...args) function, which calls fs.close for you. An error from fs.close (if any) will be combined with your error (if any).
This pattern ensures that our readExactly function doesn't leak fd's.
readExactly('readme.md', 0, 10, function (err, buf) {
console.log(buf.toString()) // '# fs-lotus'
})
readExactly('readme.md', 1e5, 10, function (err, buf) {
console.log(err.toString()) // 'Error: End of file'
})install
With npm do:
npm install fs-lotuslicense
MIT © Vincent Weevers