Like FS streams, but with stat on them, and supporting directories and symbolic links, as well as normal files. Also, you can use this to set the stats on a file, even if you don’t change its contents, or to create a symlink, etc.

So, for example, you can “write” a directory, and it’ll call mkdir. You can specify a uid and gid, and it’ll call chown. You can specify a mtime and atime, and it’ll call utimes. You can call it a symlink and provide a linkpath and it’ll call symlink.

Note that it won’t automatically resolve symbolic links. So, if you call fstream.Reader('/some/symlink') then you’ll get an object that stats and then ends immediately (since it has no data). To follow symbolic links, do this: fstream.Reader({path:'/some/symlink', follow: true }).

There are various checks to make sure that the bytes emitted are the same as the intended size, if the size is set.

Examples

  1. fstream
  2.   .Writer({ path: "path/to/file"
  3.           , mode: 0755
  4.           , size: 6
  5.           })
  6.   .write("hello\n")
  7.   .end()

This will create the directories if they’re missing, and then write hello\n into the file, chmod it to 0755, and assert that 6 bytes have been written when it’s done.

  1. fstream
  2.   .Writer({ path: "path/to/file"
  3.           , mode: 0755
  4.           , size: 6
  5.           , flags: "a"
  6.           })
  7.   .write("hello\n")
  8.   .end()

You can pass flags in, if you want to append to a file.

  1. fstream
  2.   .Writer({ path: "path/to/symlink"
  3.           , linkpath: "./file"
  4.           , SymbolicLink: true
  5.           , mode: "0755" // octal strings supported
  6.           })
  7.   .end()

If isSymbolicLink is a function, it’ll be called, and if it returns true, then it’ll treat it as a symlink. If it’s not a function, then any truish value will make a symlink, or you can set type: 'SymbolicLink', which does the same thing.

Note that the linkpath is relative to the symbolic link location, not the parent dir or cwd.

  1. fstream
  2.   .Reader("path/to/dir")
  3.   .pipe(fstream.Writer("path/to/other/dir"))

This will do like cp -Rp path/to/dir path/to/other/dir. If the other dir exists and isn’t a directory, then it’ll emit an error. It’ll also set the uid, gid, mode, etc. to be identical. In this way, it’s more like rsync -a than simply a copy.