has

has checks presence of various command line tools on the path and also reports their installed version

How ?

Download the has file. There is no dependency apart from bash itself

$ has node npm java git gradle 
✔ node 8.2.1
✔ npm 5.3.0
✔ java 1.8.0
✔ git 2.14.1
✔ gradle 4.0.1

If everything is good has exits with status code 0. The status code reflects number of commands not found on your path.

$ has node go javac
✔ node 8.2.1
✔ go 1.8.3
✘ javac

And echo the status:

$ echo $?
1

Installing

Just download the has script in your path.

git clone https://github.com/kdabir/has.git && cd has && make install

If you are lazy, you can run has directly off the internet as well:

curl -sL https://git.io/_has | bash -s git node npm
✔ git 2.14.1
✔ node 8.2.1
✔ npm 5.3.0

And if that's too much of typing every time, setup an alias

alias has="curl -sL https://git.io/_has | bash -s"

And use it

$ has git
✔ git 2.14.1

command not understood by has?

Let's say $ has foobar returns foobar not understood, because has may not have whitelisted foobar.

In such cases, pass HAS_ALLOW_UNSAFE=y has foobar. This is should still check for existance of foobar and tries to detect version as well.

the .hasrc file

has looks for .hasrc file in the directory from where has command is issued. This file can contain commands that has will check for. List one command per line. Lines starting with # are treated as comments.

Following is example of .hasrc file:

# tools
git
curl

# interpreters
ruby
node

When has is run in dir containing this file, it produces:

$ has
✔ git 2.19.1
✔ curl 7.54.0
✔ ruby 2.3.1
✔ node 10.7.0

Also, CLI arguments passed to has are additive to .hasrc file. For example, in the same dir, if the following command is fired, has checks for both commands passed from cli args and provided in .hasrc file.

$ has java
✔ java 11.0.1
✔ git 2.19.1
✔ curl 7.54.0
✔ ruby 2.3.1
✔ node 10.7.0

Pro Tip: commit .hasrc file in root of your project. This can work as a quick check for confirming presence all command line tools required to build and run your project.

on machines that don't even have has installed, your project's .hasrc is honored by this command:

curl -sL https://git.io/_has | bash -s

take a look at .hasrc file of this repo

Demo

Contributing

1. Star the repo, tweet about it, spread the word
2. Update the documentation (i.e. the README file)
3. Adding support for more commands
4. Adding more features to has

Adding Features

If you are contributing a feature, please ensure to check current tests. Add test cases for your feature. Tests are executed using excellent bats testing framework. Add tests and run make test

♥