Cocoa® Programming for Mac® OS X, Fourth Edition

Chapter 36. NSTask

Each application that you have created is a directory, and somewhere down in that directory is an executable file. To run an executable on a Unix machine, like your Mac, a process is forked, and the new process executes the code in that file. Many executables are command-line tools, and some are quite handy. This chapter, then, will be showing you how to run command-line tools from your Cocoa application by using the class NSTask.

NSTask is an easy-to-use wrapper for the Unix functions fork() and exec(). You give NSTask a path to an executable and launch it. Many processes read data from standard-in and write to standard-out and standard-error. Your application can use NSTask to attach pipes to carry data to and from the external ...