sh-realpath

A portable, pure shell implementation of realpath

Copy the functions in realpath.sh into your shell script to avoid introducing a dependency on either realpath or readlink -f, since:

• realpath does not come installed by default
• readlink -f is not portable to OS-X (relevant man page)

Usage

$ source ./realpath.sh
$ realpath /proc/self
/proc/2772

Or we can get tricky:

$ cd /tmp
$ mkdir -p somedir/targetdir somedir/anotherdir
$ ln -s somedir somedirlink
$ ln -s somedir/anotherdir/../anotherlink somelink
$ ln -s targetdir/targetpath somedir/anotherlink
$ realpath .///somedirlink/././anotherdir/../../somelink
/tmp/somedir/targetdir/targetpath

API

Note: unlike realpath(1), these functions take no options; do not use -- to escape any arguments

Function	Description

realpath PATH

| Resolve all symlinks to `PATH`, then output the canonicalized result

resolve_symlinks PATH

| If `PATH` is a symlink, follow it as many times as possible; output the path of the first non-symlink found

canonicalize_path PATH

| Output absolute path that `PATH` refers to, resolving any relative directories (`.`, `..`) in `PATH` and any symlinks in `PATH`'s ancestor directories

readlink Emulation

realpath.sh includes optional readlink emulation. It exposes a readlnk function that calls the system readlink(1) if it exists. Otherwise it uses stat(1) to emulate the same functionality. In contrast to the functions in the previous section, you may pass -- as the first argument, since you may be calling the system readlink(1).