objective-c中调用shell命令

Launching a task [permalink]

Here are the basics to launch "ls -l -a -t" in the current directory, and then read the result into an NSString:

NSTask *task;
    task = [[NSTask alloc] init];
    [task setLaunchPath: @"/bin/ls"];

    NSArray *arguments;
    arguments = [NSArray arrayWithObjects: @"-l", @"-a", @"-t", nil];
    [task setArguments: arguments];

    NSPipe *pipe;
    pipe = [NSPipe pipe];
    [task setStandardOutput: pipe];

    NSFileHandle *file;
    file = [pipe fileHandleForReading];

    [task launch];

    NSData *data;
    data = [file readDataToEndOfFile];

    NSString *string;
    string = [[NSString alloc] initWithData: data
                               encoding: NSUTF8StringEncoding];
    NSLog (@"woop!  got\n%@", string);

Performing complex pipelines. [permalink]
You can create multiple NSTasks and a bunch of NSPipes and hook them together, or you can use the "sh -c" trick to feed a shell a command, and let it parse it and set up all the IPC. This pipeline cats /usr/share/dict/words, finds all the words with 'ham' in them, reverses them, and shows you the last 5.  

NSTask *task;
    task = [[NSTask alloc] init];
    [task setLaunchPath: @"/bin/sh"];

    NSArray *arguments;
    arguments = [NSArray arrayWithObjects: @"-c",
                         @"cat /usr/share/dict/words | grep -i ham | rev | tail -5", nil];
    [task setArguments: arguments];
    // and then do all the other jazz for running an NSTask.

http://borkware.com/quickies/one?topic=nstask