Ecosyste.ms: Awesome

An open API service indexing awesome lists of open source software.

Awesome Lists | Featured Topics | Projects

https://github.com/dtcooper/fakehostname

Run a command and fake your hostname.
https://github.com/dtcooper/fakehostname

Last synced: 23 days ago
JSON representation

Run a command and fake your hostname.

Awesome Lists containing this project

README 

        
# `fakehostname` - A Command To Fake Your Hostname!



_Wow!_ Now you can run a command and fake your hostname!



## tl;dr



### Usage



Usage is relatively simple: `fakehostname   [ ...]`



For example on Linux,



```bash

$ fakehostname joan hostname

joan



$ fakehostname rivers uname -n

rivers

```



Or you can use the library directly, ie with `libfakehostname.so` in the current

directory,



```bash

$ LD_PRELOAD=./libfakehostname.so FAKE_HOSTNAME=joan-rivers hostname

joan-rivers

```



Note you _can_ use `fakehostname` on macOS, but it's a little tricky and you

should read the [note below](#important-note-for-apples-macos-darwin).



### Installation



## All Platforms (From Source)



Fetch the source from Github and install! You'll need git and

[GCC](https://gcc.gnu.org/)



```bash

git clone https://github.com/dtcooper/fakehostname.git

cd fakehostname

make

sudo make install

```



### On Debian/Ubuntu Linux (From Source)



You can install the build requirements via,



```bash

sudo apt-get install -y git build-essential

```



And then run the commands above



### On Debian/Ubuntu Linux (Prebuilt Package)



You can also install the package for the `amd64` and `arm64` architectures,

which I've built and uploaded to the

[Releases Page](https://github.com/dtcooper/fakehostname/releases/latest).



Or try this fun single command which does the same,



```bash

wget -O - https://api.github.com/repos/dtcooper/fakehostname/releases/latest \

    | grep "browser_download_url.*$(dpkg --print-architecture).deb" | cut -d '"' -f 4 \

    | wget -i - -O /tmp/fhn.deb && sudo dpkg -i /tmp/fhn.deb && rm /tmp/fhn.deb

```



### On Arch Linux



Install from the [AUR](https://aur.archlinux.org/), with an

[AUR helper](https://wiki.archlinux.org/title/AUR_helpers). The example below

uses [Yay](https://github.com/Jguer/yay),



```bash

yay -S fakehostname

```



## Overview



The command (`fakehostname`), and its associated library (`libfakehostname`),

are a hack that slip between your program and the C standard library to monkey

patch the `uname` and `gethostname` functions provided therein. This is

accomplished via the `LD_PRELOAD` environment variables on Linux, and the

`DYLD_INSERT_LIBRARIES` + `DYLD_FORCE_FLAT_NAMESPACE` evironment variables on

macOS (see [important note below](#important-note-for-apples-macos-darwin)).

The library reads environment variable `FAKE_HOSTNAME` -- prepped by the command

-- and uses that instead of your system's hostname.



This software has been tested on macOS 10.11 (El Capitan) and Ubuntu 16.04 LTS

\+ 17.10.



## Important Note for Apple's macOS (Darwin)



On macOS, starting with 10.11 (El Capitan), a feature called [System Integrity

Protection](https://en.wikipedia.org/wiki/System_Integrity_Protection) was

introduced that disallows the dynamic insertion of libraries for system

executables. One therefore can't use the environment variable

`DYLD_INSERT_LIBRARIES` to actually use `libfakehostname`'s implementation of

the `uname` and `gethostname`.



You'll have to use executables that aren't in your system's path, ie `/bin`,

`/usr/bin`, et cetera. For example, to use the `hostname` command, you'll have

to copy it locally.



```bash

# Run on a Mac named "joan" and it doesn't work, since `hostname` is in /bin

$ fakehostname rivers hostname

joan



# So we copy the `hostname` command locally, and hurray, it works!

$ cp /bin/hostname .

$ fakehostname rivers ./hostname

rivers

```



Unfortunately, this renders this software relatively useless on macOS. Oh well!



## Running The Tests



There a couple simple tests for the command, namely running `uname` and

`hostname` and verifying it actually works.



```bash

make test

```



If all goes well, you should see a `SUCCESS: All N/N tests passed!` message!



## Uninstalling



Uninstall with one command,



```bash

sudo make uninstall

```



## Final Note



_...and remember kids, have fun!_



## Author and License



This project was created by [David Cooper](http://dtcooper.com/) and is licensed

under the MIT License. See the

[`LICENSE`](https://github.com/dtcooper/fakehostname/blob/master/LICENSE) file

for details.