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NSTask with multiple pipe entries

I am trying to use pipes to process a command that requires multiple inputs, but am not quite sure how to do this. Here is a snippet of what I'm trying to do. I know how to handle the first input, but I'm lost, like on a pipe in the second input-newstdinpass

NSTask *task = [[NSTask alloc] init];
NSPipe *pipe = [NSPipe pipe];

[task setLaunchPath: @"/bin/sh"];
[task setArguments: [NSArray arrayWithObjects: @"-c", @"/usr/bin/hdiutil chpass -oldstdinpass -newstdinpass /path/to/dmg", nil]];
[task setStandardInput:pipe];
[task launch];

[[pipe fileHandleForWriting] writeData:[@"thepassword" dataUsingEncoding:NSUTF8StringEncoding]];
[[pipe fileHandleForWriting] closeFile];

[task waitUntilExit];
[task release];

So, I know that using it hdiutilthis way is a bit of a hack, but in terms of pipes, am I doing it right?

Thank.

UPDATE . In case others are wondering about this, a quick fix to my problem is to pass a zero-terminated string as pointed out by Ken Thomases. Use [[NSString stringWithFormat:@"oldpass\0newpass\0"] dataUsingEncoding:NSUTF8StringEncoding]in a pipe. Now you still need to learn how to fasten several NSTasksusing pipes ...

+3
2

NSTask NSPipe , sh -c, shell, IPC.

:

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

, "" , ...

:

/*******************************************************
 *
 * MAIN ROUTINE
 *
 *******************************************************/

- (void)runCommand:(NSString *)cmd withArgs:(NSArray *)argsArray
{
    //-------------------------------
    // Set up Task
    //-------------------------------

    if (task) { [self terminate]; }

    task = [[NSTask alloc] init];
    [task setLaunchPath:cmd];
    [task setArguments:argsArray];

    [task setStandardOutput:[NSPipe pipe]];
    [task setStandardError:[task standardOutput]];

    //-------------------------------
    // Set up Observers
    //-------------------------------

    [PP_NOTIFIER removeObserver:self];
    [PP_NOTIFIER addObserver:self 
                    selector:@selector(commandSentData:) 
                        name: NSFileHandleReadCompletionNotification 
                      object: [[task standardOutput] fileHandleForReading]];

    [PP_NOTIFIER addObserver:self 
                    selector:@selector(taskTerminated:) 
                        name:NSTaskDidTerminateNotification 
                      object:nil];

    //-------------------------------
    // Launch
    //-------------------------------
    [[[task standardOutput] fileHandleForReading] readInBackgroundAndNotify];

    [task launch];
}

/*******************************************************
 *
 * OBSERVERS
 *
 *******************************************************/

- (void)commandSentData:(NSNotification*)n
{
    NSData* d;
    d = [[n userInfo] valueForKey:NSFileHandleNotificationDataItem];

    if ([d length])
    {
        NSString* s = [[NSString alloc] initWithData:d encoding:NSUTF8StringEncoding];

        NSLog(@"Received : %@",s);
    }

    [[n object] readInBackgroundAndNotify]; 
}

- (void)taskTerminated:(NSNotification*)n
{
    [task release];
    task = nil;
}
+3

.

, /bin/sh. NSTask, @"/usr/bin/hdiutil", @"chpass", @"-oldstdinpass", @"-newstdinpass" @"/path/to/dmg". . , , dmg , , $?

, .

+2

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