NSDictionary *error = nil;
//AppleScript to get all running windows
NSAppleScript *appleScriptFindWindows = [[NSAppleScript alloc] initWithSource:
#"tell application \"System Events\" to get the title of every window of process \"TestWindow\" whose name contains \"Black\" end tell"];
while (true) {
#autoreleasepool {
//Execute and get the result of the OSAScript
NSAppleEventDescriptor *result = [appleScriptFindWindows executeAndReturnError:&error];
//Convert the result to a string
NSString *windowNames = [NSString stringWithFormat:#"%#", result];
error = nil;
sleep(0.25);
}
}
I know I am not currently doing anything with result but I will do once I have the issue fixed.
I will be monitoring various windows/files using applescript on a continuous loop, however I have noticed that when I run this code my memory usage skyrockets at 12mb/s and energy impact is high. I cannot release or de-alloc AppleEventDescriptor because of arc.
Is there a way to release the event descriptor or perhaps I am missing something in the applescript itself to correctly exit after execution?
I am a bit lost on this one and being new to obj-c I am wondering if there is a better way to execute applescript within obj-c if that is the issue.
Related
I've been trying to figure out how to run applescript in a objective-c program but so far haven't been able to.
Regardless of how I load the source into the NSAppleScript object, I simply can't get it to compile. Loading from a file returns a nil and loading from source just plain refuses to compile.
I am not an objective-c programmer in any respect and I am having a hard time figuring out how this brain dead language works. Any and all problems are likely correlated to my inability to comprehend why a constructor changes its name based on the arguments you give it.
Example source of one of my many attempts: (note, the script is correct and works fine in Script Editor)
#import <Foundation/Foundation.h>
int main(int argc, const char * argv[]) {
#autoreleasepool {
NSString * source =
#"to go_home()\n"
" tell application \"Finder\" to open \"Home\"\n"
"end go_home\n"
"go_home()";
NSAppleScript * script = [[NSAppleScript alloc] initWithSource: source];
if ( script == nil)
NSLog(#"Script is nil");
NSLog(#"Script source = %#", script.source);
[script compileAndReturnError: nil];
[script executeAndReturnError: nil];
if ([script isCompiled])
NSLog(#"Script is compiled");
else
NSLog(#"Script is not compiled");
}
return 0;
}
Example output:
2017-12-05 11:05:48.249206+0100 applescript[11826:744415] Script source = to go_home()
tell application "Finder" to open "Home"
end go_home
go_home()
2017-12-05 11:05:48.262797+0100 applescript[11826:744415] Script is not compiled
Program ended with exit code: 0
Edit: It appears that the problem is related to XCode. When I compile the program in a terminal, everything works fine.
i am getting Script is compiled
Program ended with exit code: 0 for same code.
you can check error by replacing
[script compileAndReturnError: nil];
[script executeAndReturnError: nil];
with
NSDictionary *error;
[script compileAndReturnError: &error];
[script executeAndReturnError: &error];
Since updating to OSX 10.7 Lion, Xcode tells me that AuthorizationExecuteWithPrivileges is deprecated.
Can anyone suggest a way my application can write to a directory it doesn't have permission for?
I know it sounds crazy, but this actually works:
NSDictionary *error = [NSDictionary new];
NSString *script = #"do shell script \"whoami > /tmp/me\" with administrator privileges";
NSAppleScript *appleScript = [[NSAppleScript alloc] initWithSource:script];
if ([appleScript executeAndReturnError:&error]) {
NSLog(#"success!");
} else {
NSLog(#"failure!");
}
I'm executing an Applescript from Objective C. The only disadvantage is that you cannot gain permanent root privileges with this. It will ask for the password each time you run this.
In fact, AuthorizationExecuteWithPrivileges() has been deprecated for a very long time, it's only recently that the header file has caught up with this fact.
You can create a privileged helper tool as part of your application. You can use ServiceManagement.framework's SMJobBless() function to have the helper deployed into the system launchd context: then when you need to perform privileged tasks, you just message the privileged helper to do that work.
There's a little bit of hidden complexity, in that the app and the helper must each declare the signing identity of the other before SMJobBless() believes they're supposed to be used together, and you need to get the linker to write the helper tool's Info.plist file into the binary. That's all covered by Apple's Documentation and Apple have provided a sample project, too.
I wrote an example application that uses SMJobBless() to deploy its privileged helper.
Based on a great find by user950473 I've implemented his/her discovery as a method; thought I'd share the code in case it's helpful.
- (BOOL) runProcessAsAdministrator:(NSString*)scriptPath
withArguments:(NSArray *)arguments
output:(NSString **)output
errorDescription:(NSString **)errorDescription {
NSString * allArgs = [arguments componentsJoinedByString:#" "];
NSString * fullScript = [NSString stringWithFormat:#"'%#' %#", scriptPath, allArgs];
NSDictionary *errorInfo = [NSDictionary new];
NSString *script = [NSString stringWithFormat:#"do shell script \"%#\" with administrator privileges", fullScript];
NSAppleScript *appleScript = [[NSAppleScript new] initWithSource:script];
NSAppleEventDescriptor * eventResult = [appleScript executeAndReturnError:&errorInfo];
// Check errorInfo
if (! eventResult)
{
// Describe common errors
*errorDescription = nil;
if ([errorInfo valueForKey:NSAppleScriptErrorNumber])
{
NSNumber * errorNumber = (NSNumber *)[errorInfo valueForKey:NSAppleScriptErrorNumber];
if ([errorNumber intValue] == -128)
*errorDescription = #"The administrator password is required to do this.";
}
// Set error message from provided message
if (*errorDescription == nil)
{
if ([errorInfo valueForKey:NSAppleScriptErrorMessage])
*errorDescription = (NSString *)[errorInfo valueForKey:NSAppleScriptErrorMessage];
}
return NO;
}
else
{
// Set output to the AppleScript's output
*output = [eventResult stringValue];
return YES;
}
}
Usage example:
NSString * output = nil;
NSString * processErrorDescription = nil;
BOOL success = [self runProcessAsAdministrator:#"/usr/bin/id"
withArguments:[NSArray arrayWithObjects:#"-un", nil]
output:&output
errorDescription:&processErrorDescription];
if (!success) // Process failed to run
{
// ...look at errorDescription
}
else
{
// ...process output
}
It's very slightly hacky, but IMHO is a satisfactory solution.
AuthorizationExecuteWithPrivileges is indeed deprecated.
But fortunately, there is a new recommended way to proceed.
As of 10.6 there is the new API and it is recommended to install a helper tool that will perform the privileged operation. Apple provide a code sample that clearly demonstrate how to manage it.
Make sure you check out their readme.txt since contrarily to other code sample there is more to do than just downloading the project and running it.
From The SMJobBless example introduction
SMJobBless demonstrates how to securely install a helper tool that performs a privileged operation and how to associate the tool
with an application that invokes it.
As of Snow Leopard, this is the preferred method of managing privilege
escalation on Mac OS X and should be used instead of earlier
approaches such as BetterAuthorizationSample or directly calling
AuthorizationExecuteWithPrivileges.
SMJobBless uses ServiceManagement.framework that was introduced in Mac
OS X v10.6 Snow Leopard.
Source: Apple SMJobBless code sample
I've been trying to make do (see this and this) with the recent NSUserScriptTask class and its subclasses and so far I've solved some problems, but some others remain to be solved. As you can see from the docs, NSUserScriptTask does not allow for the cancellation of tasks. So, I decided to create a simple executable that takes as arguments the path to the script and runs the script. That way, I can launch the helper from my main app using NSTask and call [task terminate] when necessary. However, I require:
The main app to receive output and errors from the helper it launched
The helper only terminating when the NSUserScriptTask is done
The code for the main app is simple: just launch an NSTask with the proper info. Here's what I have now (for the sake of simplicity I ignored the code for security-scoped bookmarks and the like, which are out of the problem. But don't forget this is running sandboxed):
// Create task
task = [NSTask new];
[task setLaunchPath: [[NSBundle mainBundle] pathForResource: #"ScriptHelper" ofType: #""]];
[task setArguments: [NSArray arrayWithObjects: scriptPath, nil]];
// Create error pipe
NSPipe* errorPipe = [NSPipe new];
[task setStandardError: errorPipe];
// Create output pipe
NSPipe* outputPipe = [NSPipe new];
[task setStandardOutput: outputPipe];
// Set termination handler
[task setTerminationHandler: ^(NSTask* task){
// Save output
NSFileHandle* outFile = [outputPipe fileHandleForReading];
NSString* output = [[NSString alloc] initWithData: [outFile readDataToEndOfFile] encoding: NSUTF8StringEncoding];
if ([output length]) {
[output writeToFile: outputPath atomically: NO encoding: NSUTF8StringEncoding error: nil];
}
// Log errors
NSFileHandle* errFile = [errorPipe fileHandleForReading];
NSString* error = [[NSString alloc] initWithData: [errFile readDataToEndOfFile] encoding: NSUTF8StringEncoding];
if ([error length]) {
[error writeToFile: errorPath atomically: NO encoding: NSUTF8StringEncoding error: nil];
}
// Do some other stuff after the script finished running <-- IMPORTANT!
}];
// Start task
[task launch];
Remember, I need the termination handler to only run when: (a) the task was cancelled (b) the task terminated on its own because the script finished running.
Now, on the helper side things start to get hairy, at least for me. Let's imagine for the sake of simplicity that the script is an AppleScript file (so I use the NSUserAppleScriptTask subclass - on the real world I'd have to accomodate for the three types of tasks). Here's what I got so far:
int main(int argc, const char * argv[])
{
#autoreleasepool {
NSString* filePath = [NSString stringWithUTF8String: argv[1]];
__block BOOL done = NO;
NSError* error;
NSUserAppleScriptTask* task = [[NSUserAppleScriptTask alloc] initWithURL: [NSURL fileURLWithPath: filePath] error: &error];
NSLog(#"Task: %#", task); // Prints: "Task: <NSUserAppleScriptTask: 0x1043001f0>" Everything OK
if (error) {
NSLog(#"Error creating task: %#", error); // This is not printed
return 0;
}
NSLog(#"Starting task");
[task executeWithAppleEvent: nil completionHandler: ^(NSAppleEventDescriptor *result, NSError *error) {
NSLog(#"Finished task");
if (error) {
NSLog(#"Error running task: %#", error);
}
done = YES;
}];
// Wait until (done == YES). How??
}
return 0;
}
Now, I have three questions (which are the ones I want to ask with this SO entry). Firstly, "Finished task" never gets printed (the block never gets called) because the task never even starts executing. Instead, I get this on my console:
MessageTracer: msgtracer_vlog_with_keys:377: odd number of keys (domain: com.apple.automation.nsuserscripttask_run, last key: com.apple.message.signature)
I tried running the exact same code from the main app and it completes without a fuss (but from the main app I lose the ability to cancel the script).
Secondly, I only want to reach the end of main (return 0;) after the completion handler is called. But I have no idea how to do that.
Thridly, whenever there's an error or output from the helper I want to send that error/output back to the app, which will receive them through the errorPipe/outputPipe. Something like fprintf(stderr/stdout, "string") does the trick, but I'm not sure if it is the right way to do it.
So, in short, any help regarding the first and second problems is appreciated. The third one I just want to make sure that's how I'm supposed to do it.
Thanks
Question 1: The sub-task doesn't run because its parent exits immediately. (The log message about "odd number of keys" is a bug in NSUserScriptTask, and happens because your helper doesn't have a bundle identifier, but is otherwise harmless and irrelevant to your problem.) It exits immediately because it's not waiting for the completion block to fire, which brings us to...
Question 2: How do you wait for an asynchronous completion block? This has been answered elsewhere, including Wait until multiple networking requests have all executed - including their completion blocks, but to recap, use dispatch groups, something like this:
dispatch_group_t g = dispatch_group_create();
dispatch_group_enter(g);
[task executeWithAppleEvent:nil completionHandler:^(NSAppleEventDescriptor *result, NSError *e) {
...
dispatch_group_leave(g);
}];
dispatch_group_wait(g, DISPATCH_TIME_FOREVER);
dispatch_release(g);
This same pattern works for any call that has a completion block you want to wait for. If you wanted another notification when the group finishes instead of waiting for it, use dispatch_group_notify instead of dispatch_group_wait.
As a side note, the way you’re testing error after allocating the NSUserAppleScriptTask is incorrect. The value of error is defined if and only if the function result is nil (or NO, or whatever indicates failure). If the function succeeds (which you know if it returns non-nil), then error may be anything -- the function may set it to nil, it may leave it undefined, it may even fill it in with a real object. (See also What's the Point of (NSError**)error?)
Since updating to OSX 10.7 Lion, Xcode tells me that AuthorizationExecuteWithPrivileges is deprecated.
Can anyone suggest a way my application can write to a directory it doesn't have permission for?
I know it sounds crazy, but this actually works:
NSDictionary *error = [NSDictionary new];
NSString *script = #"do shell script \"whoami > /tmp/me\" with administrator privileges";
NSAppleScript *appleScript = [[NSAppleScript alloc] initWithSource:script];
if ([appleScript executeAndReturnError:&error]) {
NSLog(#"success!");
} else {
NSLog(#"failure!");
}
I'm executing an Applescript from Objective C. The only disadvantage is that you cannot gain permanent root privileges with this. It will ask for the password each time you run this.
In fact, AuthorizationExecuteWithPrivileges() has been deprecated for a very long time, it's only recently that the header file has caught up with this fact.
You can create a privileged helper tool as part of your application. You can use ServiceManagement.framework's SMJobBless() function to have the helper deployed into the system launchd context: then when you need to perform privileged tasks, you just message the privileged helper to do that work.
There's a little bit of hidden complexity, in that the app and the helper must each declare the signing identity of the other before SMJobBless() believes they're supposed to be used together, and you need to get the linker to write the helper tool's Info.plist file into the binary. That's all covered by Apple's Documentation and Apple have provided a sample project, too.
I wrote an example application that uses SMJobBless() to deploy its privileged helper.
Based on a great find by user950473 I've implemented his/her discovery as a method; thought I'd share the code in case it's helpful.
- (BOOL) runProcessAsAdministrator:(NSString*)scriptPath
withArguments:(NSArray *)arguments
output:(NSString **)output
errorDescription:(NSString **)errorDescription {
NSString * allArgs = [arguments componentsJoinedByString:#" "];
NSString * fullScript = [NSString stringWithFormat:#"'%#' %#", scriptPath, allArgs];
NSDictionary *errorInfo = [NSDictionary new];
NSString *script = [NSString stringWithFormat:#"do shell script \"%#\" with administrator privileges", fullScript];
NSAppleScript *appleScript = [[NSAppleScript new] initWithSource:script];
NSAppleEventDescriptor * eventResult = [appleScript executeAndReturnError:&errorInfo];
// Check errorInfo
if (! eventResult)
{
// Describe common errors
*errorDescription = nil;
if ([errorInfo valueForKey:NSAppleScriptErrorNumber])
{
NSNumber * errorNumber = (NSNumber *)[errorInfo valueForKey:NSAppleScriptErrorNumber];
if ([errorNumber intValue] == -128)
*errorDescription = #"The administrator password is required to do this.";
}
// Set error message from provided message
if (*errorDescription == nil)
{
if ([errorInfo valueForKey:NSAppleScriptErrorMessage])
*errorDescription = (NSString *)[errorInfo valueForKey:NSAppleScriptErrorMessage];
}
return NO;
}
else
{
// Set output to the AppleScript's output
*output = [eventResult stringValue];
return YES;
}
}
Usage example:
NSString * output = nil;
NSString * processErrorDescription = nil;
BOOL success = [self runProcessAsAdministrator:#"/usr/bin/id"
withArguments:[NSArray arrayWithObjects:#"-un", nil]
output:&output
errorDescription:&processErrorDescription];
if (!success) // Process failed to run
{
// ...look at errorDescription
}
else
{
// ...process output
}
It's very slightly hacky, but IMHO is a satisfactory solution.
AuthorizationExecuteWithPrivileges is indeed deprecated.
But fortunately, there is a new recommended way to proceed.
As of 10.6 there is the new API and it is recommended to install a helper tool that will perform the privileged operation. Apple provide a code sample that clearly demonstrate how to manage it.
Make sure you check out their readme.txt since contrarily to other code sample there is more to do than just downloading the project and running it.
From The SMJobBless example introduction
SMJobBless demonstrates how to securely install a helper tool that performs a privileged operation and how to associate the tool
with an application that invokes it.
As of Snow Leopard, this is the preferred method of managing privilege
escalation on Mac OS X and should be used instead of earlier
approaches such as BetterAuthorizationSample or directly calling
AuthorizationExecuteWithPrivileges.
SMJobBless uses ServiceManagement.framework that was introduced in Mac
OS X v10.6 Snow Leopard.
Source: Apple SMJobBless code sample
I'm using some AppleScript in my Obj-C cocoa project to control QuickTime player (play, pause, stop, jog forward and back etc.) with great success, though my knowledge of AppleScript is very limited.
However, what I want most of all is the movie's 'Current Time' offset to convert into time-stamps for writing a subtitle script.
The following simple method shows the precise current position in (float) seconds in a dialog, but I'd really like the AppleScript to return me a variable that I can use in the rest of app. How could I modify the code below to do that? Is it even possible to access this value? Thanks a million in advance :-)
-(IBAction)currentPlayTime:(id)sender
{
NSString *scriptString=[NSString stringWithFormat:
// get time of current frame... (works perfectly)!
#"tell application \"QuickTime Player\"\n"
#"set timeScale to 600\n"
#"set curr_pos to current time of movie 1/timeScale\n"
#"display dialog curr_pos\n" // ...not in a practical form to use
#"end tell\n"];
NSDictionary *errorDict= nil;
NSAppleScript *appleScriptObject=[[NSAppleScript alloc] initWithSource:scriptString];
NSAppleEventDescriptor *eventDescriptor=[appleScriptObject executeAndReturnError: &errorDict];
// handle any errors here (snipped for brevity)
[appleScriptObject release]; // can I retain this?
}
Here's the appropriate AppleScript that you'd want to run:
property timeScale : 600
set currentPosition to missing value
tell application "QuickTime Player"
set currentPosition to (current time of document 1) / timeScale
end tell
return currentPosition
In case you're not familiar with it, property is a way to specify a global variable in AppleScript. Also, missing value is the AppleScript equivalent of nil in Objective-C. So, this script first defines a variable named currentPosition, and sets the value to missing value. It then enters the tell block which, if it succeeds, will alter the currentPosition variable. Then, outside of the tell block, it returns the currentPosition variable.
In the Objective-C code, when you create an NSAppleScript with the above code, its -executeAndReturnError: method will return the currentPosition variable in an NSAppleScriptEventDescriptor.
-(IBAction)currentPlayTime:(id)sender {
NSDictionary *error = nil;
NSMutableString *scriptText = [NSMutableString stringWithString:#"property timeScale : 600\n"];
[scriptText appendString:#"set currentPosition to missing value\n"];
[scriptText appendString:#"tell application \"QuickTime Player\"\n "];
[scriptText appendString:#"set currentPosition to (current time of document 1) / timeScale\n"];
[scriptText appendString:#"end tell\n"];
[scriptText appendString:#"return currentPosition\n"];
NSAppleScript *script = [[[NSAppleScript alloc] initWithSource:scriptText] autorelease];
NSAppleEventDescriptor *result = [script executeAndReturnError:&error];
NSLog(#"result == %#", result);
DescType descriptorType = [result descriptorType];
NSLog(#"descriptorType == %#", NSFileTypeForHFSTypeCode(descriptorType));
// returns a double
NSData *data = [result data];
double currentPosition = 0;
[data getBytes:¤tPosition length:[data length]];
NSLog(#"currentPosition == %f", currentPosition);
}
You can extract the contents of the NSAppleEventDescriptor as shown above.
Using the Scripting Bridge framework does have a slight learning curve, but would allow working with native types such as NSNumbers rather than having to go the somewhat "messier" route of extracting the raw bytes out of AppleEvent descriptor.
Use Scripting Bridge. This is a bridge between AppleScript and Objective-C, and other applications (e.g. QuickTime Player) is represented as an Objectve-C object in your code. So, you don't have to construct AppleScript code by hand.
Some say AppScript is better than Scripting Bridge.
NSAppleEventDescriptor has some methods to convert to some objective-C types, if you go to my site and download the NDScript project, it has a category of NSAppleEventDescriptor which adds a lot more methods for coercion to Objective-C type. You can use that category without the rest of the project.
http://homepage.mac.com/nathan_day/pages/source.xml