除了上面的几个出色的答案之外，我还使用以下代码在后台处理命令的输出，并避免[file readDataToEndOfFile]的阻塞机制。

- (void)runCommand:(NSString *)commandToRun
{
    NSTask *task = [[NSTask alloc] init];
    [task setLaunchPath:@"/bin/sh"];

    NSArray *arguments = [NSArray arrayWithObjects:
                          @"-c" ,
                          [NSString stringWithFormat:@"%@", commandToRun],
                          nil];
    NSLog(@"run command:%@", commandToRun);
    [task setArguments:arguments];

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

    NSFileHandle *file = [pipe fileHandleForReading];

    [task launch];

    [self performSelectorInBackground:@selector(collectTaskOutput:) withObject:file];
}

- (void)collectTaskOutput:(NSFileHandle *)file
{
    NSData      *data;
    do
    {
        data = [file availableData];
        NSLog(@"%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] );

    } while ([data length] > 0); // [file availableData] Returns empty data when the pipe was closed

    // Task has stopped
    [file closeFile];
}

你可以使用NSTask。下面是一个运行'/usr/bin/grep foo bar.txt'的例子。

int pid = [[NSProcessInfo processInfo] processIdentifier];
NSPipe *pipe = [NSPipe pipe];
NSFileHandle *file = pipe.fileHandleForReading;

NSTask *task = [[NSTask alloc] init];
task.launchPath = @"/usr/bin/grep";
task.arguments = @[@"foo", @"bar.txt"];
task.standardOutput = pipe;

[task launch];

NSData *data = [file readDataToEndOfFile];
[file closeFile];

NSString *grepOutput = [[NSString alloc] initWithData: data encoding: NSUTF8StringEncoding];
NSLog (@"grep returned:\n%@", grepOutput);

nspope和NSFileHandle用于重定向任务的标准输出。

有关在Objective-C应用程序中与操作系统交互的更详细信息，您可以查看Apple开发中心的这篇文档:与操作系统交互。

编辑:包括修复NSLog问题

如果你正在使用NSTask通过bash运行命令行实用程序，那么你需要包括这条神奇的行来保持NSLog工作:

//The magic line that keeps your log where it belongs
task.standardOutput = pipe;

解释在这里:https://web.archive.org/web/20141121094204/https://cocoadev.com/HowToPipeCommandsWithNSTask

或者因为Objective C只是C，上面有一些OO层，你可以使用posix对等物:

int execl(const char *path, const char *arg0, ..., const char *argn, (char *)0);
int execle(const char *path, const char *arg0, ..., const char *argn, (char *)0, char *const envp[]);
int execlp(const char *file, const char *arg0, ..., const char *argn, (char *)0);
int execlpe(const char *file, const char *arg0, ..., const char *argn, (char *)0, char *const envp[]);
int execv(const char *path, char *const argv[]);
int execve(const char *path, char *const argv[], char *const envp[]);
int execvp(const char *file, char *const argv[]);
int execvpe(const char *file, char *const argv[], char *const envp[]); 

它们包含在unistd.h头文件中。

除了上面的几个出色的答案之外，我还使用以下代码在后台处理命令的输出，并避免[file readDataToEndOfFile]的阻塞机制。

- (void)runCommand:(NSString *)commandToRun
{
    NSTask *task = [[NSTask alloc] init];
    [task setLaunchPath:@"/bin/sh"];

    NSArray *arguments = [NSArray arrayWithObjects:
                          @"-c" ,
                          [NSString stringWithFormat:@"%@", commandToRun],
                          nil];
    NSLog(@"run command:%@", commandToRun);
    [task setArguments:arguments];

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

    NSFileHandle *file = [pipe fileHandleForReading];

    [task launch];

    [self performSelectorInBackground:@selector(collectTaskOutput:) withObject:file];
}

- (void)collectTaskOutput:(NSFileHandle *)file
{
    NSData      *data;
    do
    {
        data = [file availableData];
        NSLog(@"%@", [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding] );

    } while ([data length] > 0); // [file availableData] Returns empty data when the pipe was closed

    // Task has stopped
    [file closeFile];
}

in the spirit of sharing... this is a method I use frequently to run shell scripts. you can add a script to your product bundle (in the copy phase of the build) and then have the script be read and run at runtime. note: this code looks for the script in the privateFrameworks sub-path. warning: this could be a security risk for deployed products, but for our in-house development it is an easy way to customize simple things (like which host to rsync to...) without re-compiling the application, but just editing the shell script in the bundle.

//------------------------------------------------------
-(void) runScript:(NSString*)scriptName
{
    NSTask *task;
    task = [[NSTask alloc] init];
    [task setLaunchPath: @"/bin/sh"];

    NSArray *arguments;
    NSString* newpath = [NSString stringWithFormat:@"%@/%@",[[NSBundle mainBundle] privateFrameworksPath], scriptName];
    NSLog(@"shell script path: %@",newpath);
    arguments = [NSArray arrayWithObjects:newpath, 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 (@"script returned:\n%@", string);    
}
//------------------------------------------------------

编辑:包括修复NSLog问题

如果你正在使用NSTask通过bash运行命令行实用程序，那么你需要包括这条神奇的行来保持NSLog工作:

//The magic line that keeps your log where it belongs
[task setStandardInput:[NSPipe pipe]];

时代背景:

NSPipe *pipe;
pipe = [NSPipe pipe];
[task setStandardOutput: pipe];
//The magic line that keeps your log where it belongs
[task setStandardInput:[NSPipe pipe]];

解释在这里:http://www.cocoadev.com/index.pl?NSTask

还有一个很好的老式POSIX系统("echo -en '\007'");