Cocoa in a Nutshell

Operating System Interaction

The Foundation framework provides many services through a small set of classes that allow developers to interact with the underlying operating system in several ways. NSTask is an object-oriented interface to configure and launch a process as a subprocess of the current application. NSProcessInfo lets an application discover information about its current process.

Process Info

Example 2-35 shows some of the information you can obtain by using NSProcessInfo.

Example 2-35. Using NSProcessInfo

                     // Get the shared process info object for the current process
NSProcessInfo *proc = [NSProcessInfo processInfo];

// The name and PID of the process
NSString *name = [proc processName];
int pid = [proc processIdentifier];

// The arguments launched with the process
NSArray *args = [proc arguments];

// A dictionary of the environment variables for the process
NSDictionary *env = [proc environment];

// The host name for the host running the process
NSString *host = [proc hostName];

// The operating system version string
                     // Note: this string is NOT appropriate for parsing
NSString *ver = [proc operatingSystemVersionString];

Tasks

NSTask is a class that lets a program configure, launch, and communicate with another program as a subprocess. This is something you’ll see every time you execute an application you work on from within Project Builder.

An NSTask is launched in a fully configurable execution environment where environment variables, command line options, and other ...