upath

Documentation

Overview

Package upath contains utilities for dealing with symlinked paths.

Index

• func AbsSymlink(originalFile, target string) string
• func IsTargetSymlink(originalFile, target string) bool
• func ResolveUntilLastSymlink(p string) string
• func SafeFilepathJoin(path1, path2 string) (string, error)
• func UrootPath(n ...string) string

Functions

func AbsSymlink

func AbsSymlink(originalFile, target string) string

AbsSymlink returns an absolute path for the link from a file to a target.

func IsTargetSymlink

func IsTargetSymlink(originalFile, target string) bool

IsTargetSymlink returns true if a target of a symlink is also a symlink.

func ResolveUntilLastSymlink

func ResolveUntilLastSymlink(p string) string

ResolveUntilLastSymlink resolves until the last symlink.

This is needed when we have a chain of symlinks and want the last symlink, not the file pointed to (which is why we don't use filepath.EvalSymlinks)

I.e.

/foo/bar -> ../baz/foo /baz/foo -> bla

ResolveUntilLastSymlink(/foo/bar) returns /baz/foo.

func SafeFilepathJoin

func SafeFilepathJoin(path1, path2 string) (string, error)

SafeFilepathJoin safely joins two paths path1+path2. The resulting path will always be contained within path1 even if path2 tries to escape with "../". If that path is not possible, an error is returned. The resulting path is cleaned.

func UrootPath

func UrootPath(n ...string) string

UrootPath returns the absolute path for a uroot file with the UROOT_ROOT environment variable taken into account.

It returns a proper value if UROOT_ROOT is not set. u-root was built to assume everything is rooted at /, and in most cases that is still true. But in hosted mode, e.g. on developer mode chromebooks, it's far better if u-root can be rooted in /usr/local, so successive kernel/root file system upgrades do not wipe it out.