How to execute a unix executable file with Swift - swift

Question

I developing a OS X application with swift. I need to use some library on my application. The library is a Unix executable file.
I can execute the Unix executable file on terminal.
This is example:
pngquant --quality=65-80 test.png
But I need execute the Unix executable file on OS X application. I don't know how to do it.
I think should execute command on OS X application, and find an awesome library to execute the command.
Using swiftline example:
let result = run("ls -all")
print(result.stdout)
Print content:
total 0
drwxr-xr-x 6 DevinShine staff 204 Dec 23 22:18 .
drwxr-xr-x# 3 DevinShine staff 102 Dec 23 22:16 ..
drwxr-xr-x 3 DevinShine staff 102 Dec 23 23:25 Pion.app
drwxr-xr-x 4 DevinShine staff 136 Dec 23 22:18 Pion.swiftmodule
drwxr-xr-x 7 DevinShine staff 238 Dec 23 22:18 Pods.framework
drwxr-xr-x 7 DevinShine staff 238 Dec 23 22:18 Swiftline.framework
I copy Unix executable file to Build Phases.
But I don't know how to move Unix executable file to OS X application and execute it.
Please help me,thx.

Answer 1

I resolved it. The way is easy.
I run my application and execute run("pwd")
let result = run("pwd")
print(result.stdout)
let fullPath = result.stdout + "/Pion.app/Contents/MacOS/pngquant"
print content:
/Users/apple/Library/Developer/Xcode/DerivedData/Pion-ebbvaypzstbbordxhgeutzopihtt/Build/Products/Debug
excute pngquant function:
run(fullPath + " /Users/apple/Documents/test.png")
Update at 2015-12-25
NSBundle.mainBundle().executablePath will give you the path to your .app wrapper, so code is very clear.
run(NSBundle.mainBundle().executablePath + "pngquant /Users/apple/Documents/test.png")