https://github.com/mklement0/rreadlink
A multi-platform Unix CLI that prints a symlink's complete chain of targets using absolute paths.
https://github.com/mklement0/rreadlink
cli filesystem filesystem-path symlink unix-cli
Last synced: 3 months ago
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A multi-platform Unix CLI that prints a symlink's complete chain of targets using absolute paths.
- Host: GitHub
- URL: https://github.com/mklement0/rreadlink
- Owner: mklement0
- License: other
- Created: 2015-02-11T19:11:41.000Z (over 10 years ago)
- Default Branch: master
- Last Pushed: 2022-12-27T13:55:18.000Z (over 2 years ago)
- Last Synced: 2025-02-19T05:17:10.649Z (4 months ago)
- Topics: cli, filesystem, filesystem-path, symlink, unix-cli
- Language: Makefile
- Homepage:
- Size: 47.9 KB
- Stars: 12
- Watchers: 5
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE.md
Awesome Lists containing this project
README
[](https://npmjs.com/package/rreadlink) [](https://github.com/mklement0/rreadlink/blob/master/LICENSE.md)
**Contents**
- [rreadlink — introduction](#rreadlink-&mdash-introduction)
- [Examples](#examples)
- [Installation](#installation)
- [Installation from the npm registry](#installation-from-the-npm-registry)
- [Manual installation](#manual-installation)
- [Usage](#usage)
- [License](#license)
- [Acknowledgements](#acknowledgements)
- [npm dependencies](#npm-dependencies)
- [Changelog](#changelog)
# rreadlink — introduction
`rreadlink` is a **multi-platform Unix CLI** that **prints a symlink's _complete chain_ of targets** using **_absolute_ paths**; it can
also determine the canonical path of non-symlinks.
The primary purpose of `rreadlink` (*r*ecursive *readlink*) is to follow a given symlink to its ultimate target, printing _all intermediate symlinks_ along the way.
All paths are printed as _absolute_ paths, with the ultimate target printed in _canonical_ form.
This is hepful on Linux platforms, for instance, where some utilities are installed as symlinks that point to _other_ symlinks before resolving
to the ultimate target, making it difficult to understand what is ultimately invoked;
e.g., on some Linux distros `/usr/bin/nawk` links to `/etc/alternatives/nawk`, which in turn links to the actual target, `/usr/bin/gawk`.
Note that the native GNU `readlink` utility can either only give you the _next_ target (not the ultimate one), or, with `-f` or `-e` or `-m`,
_only_ the _ultimate_ target (not intermediate ones).
Loosely speaking, `rreadlink` provides the functionality of GNU `readlink -e` while also including _intermediate_ targets.
`rreadlink` has the added advantage of being multi-platform (see [Installation](#installation) below).
Alternatively, given a _non_-symlink, `rreadlink` prints the argument's canonical path (i.e., any _directory_ components that are symlinks
are resolved to their ultimate targets).
Find examples below, concise [usage information](#usage) further below, or
read the [manual](doc/rreadlink.md).
**See also**: The [`typex`](https://github.com/mklement0/typex) utility
provides information about _executables in the path_ (among other things) and
has `rreadlink`'s behavior built in to show what file is ultimately invoked.
# Examples
```shell
# Print the symlink chain for executable /usr/bin/nawk (e.g., on Ubuntu):
$ rreadlink /usr/bin/nawk
/usr/bin/nawk@ -> /etc/alternatives/nawk@ -> /usr/bin/gawk
# Ditto, but printing one path per line, without the symlink sigil (@):
# (This format is the default when not outputting to a terminal.)
$ rreadlink -1 /usr/bin/nawk
/usr/bin/nawk
/etc/alternatives/nawk
/usr/bin/gawk
# Canonicalize the path of a non-symlink:
# (Assume that /var links to /private/var and that log is a regular file.)
$ rreadlink /var/log
/private/var/log
```
# Installation
**Supported platforms**
**Unix-like platforms** with **POSIX-compatible utilities** and
[Bash](http://www.gnu.org/software/bash/), such as Linux and OS X.
## Installation from the npm registry
Note: Even if you don't use Node.js, its package manager, `npm`, works across platforms and is easy to install; try [`curl -L http://git.io/n-install | bash`](https://github.com/mklement0/n-install)
With [Node.js](http://nodejs.org/) or [io.js](https://iojs.org/) installed, install [the package](https://www.npmjs.com/package/rreadlink) as follows:
[sudo] npm install rreadlink -g
**Note**:
* Whether you need `sudo` depends on how you installed Node.js / io.js and whether you've [changed permissions later](https://docs.npmjs.com/getting-started/fixing-npm-permissions); if you get an `EACCES` error, try again with `sudo`.
* The `-g` ensures [_global_ installation](https://docs.npmjs.com/getting-started/installing-npm-packages-globally) and is needed to put `rreadlink` in your system's `$PATH`.
## Manual installation
* Download [the CLI](https://raw.githubusercontent.com/mklement0/rreadlink/stable/bin/rreadlink) as `rreadlink`.
* Make it executable with `chmod +x rreadlink`.
* Move it or symlink it to a folder in your `$PATH`, such as `/usr/local/bin` (OSX) or `/usr/bin` (Linux).
# Usage
Find concise usage information below; for complete documentation, read the [manual online](doc/rreadlink.md) or,
once installed, run `rreadlink nws` (`rreadlink --man` if installed manually).
```nohighlight
$ rreadlink --help
Recursively resolves symlinks by printing the chain of targets using absolute
paths or prints the canonical path of a symlink's ultimate target or of a
non-symlink.
rreadlink [-s|-1] symLink
rreadlink -e symLink
-s single-line output format using ' -> ' between paths and
@ to mark symlinks (default when printing to terminal)
-1 one-line-per-path output format, without the @ marker (default
when NOT printing to a terminal)
-e print only the symlink's ultimate target, in canonical form
Standard options: --help, --man, --version, --home
```
# License
Copyright (c) 2015 Michael Klement (http://same2u.net),
released under the [MIT license](https://spdx.org/licenses/MIT#licenseText).
## Acknowledgements
This project gratefully depends on the following open-source components, according to the terms of their respective licenses.
[npm](https://www.npmjs.com/) dependencies below have optional suffixes denoting the type of dependency; the absence of a suffix denotes a required run-time dependency: `(D)` denotes a development-time-only dependency, `(O)` an optional dependency, and `(P)` a peer dependency.
## npm dependencies
* [doctoc (D)](https://github.com/thlorenz/doctoc)
* [json (D)](https://github.com/trentm/json)
* [marked-man (D)](https://github.com/kapouer/marked-man#readme)
* [replace (D)](https://github.com/harthur/replace)
* [semver (D)](https://github.com/npm/node-semver#readme)
* [shall (D)](https://github.com/mklement0/shall)
* [urchin (D)](https://git.sdf.org/tlevine/urchin)
# Changelog
Versioning complies with [semantic versioning (semver)](http://semver.org/).
* **[v0.2.1](https://github.com/mklement0/rreadlink/compare/v0.2.0...v0.2.1)** (2015-10-21):
* [dev] Improved robustness of interal `rreadlinkchain()` function.
* **[v0.2.0](https://github.com/mklement0/rreadlink/compare/v0.1.6...v0.2.0)** (2015-09-18):
* [potentially breaking change] `rreadlink` now also accepts options placed
_after_ operands on the command line (except after `--`).
* [doc] `rreadlink` now has a man page (if manually installed,
use `rreadlink --man`); `rreadlink -h` now just prints concise usage
information.
* [doc] `README.md` cleaned up and extended.
* [dev] Removed post-install command that verifies presence of Bash, because
`npm` _prints_ the command during installation, which can be confusing.
* **[v0.1.6](https://github.com/mklement0/rreadlink/compare/v0.1.5...v0.1.6)** (2015-09-15):
* [dev] Makefile improvements; various other behind-the-scenes tweaks.
* **[v0.1.5](https://github.com/mklement0/rreadlink/compare/v0.1.4...v0.1.5)** (2015-06-26):
* [doc] Read-me: npm badge changed to shields.io; license badge added; typo fixed.
* [dev] To-do added; Makefile updated.
* **v0.1.4** (2015-05-30):
* [doc] [npm registry badge](https://badge.fury.io) added.
* **v0.1.3** (2015-02-11):
* Doc: Read-me improvements.
* **v0.1.2** (2015-02-11):
* Doc: Read-me and CLI help improvements.
* **v0.1.1** (2015-02-11):
* Dev: Tests improved.
* **v0.1.0** (2015-02-11):
* Initial release.