{"id":149,"date":"2008-10-05T19:35:09","date_gmt":"2008-10-06T00:35:09","guid":{"rendered":"http:\/\/vgable.com\/blog\/2008\/10\/05\/restarting-your-cocoa-application\/"},"modified":"2009-03-18T13:33:40","modified_gmt":"2009-03-18T18:33:40","slug":"restarting-your-cocoa-application","status":"publish","type":"post","link":"https:\/\/vgable.com\/blog\/2008\/10\/05\/restarting-your-cocoa-application\/","title":{"rendered":"Restarting Your Mac OS X Cocoa Application"},"content":{"rendered":"

Restarting your own application is a tricky thing to do, because you can’t tell yourself to start up when you aren’t running. Here is one solution, use NSTask<\/a><\/code> to run a very short script that you can embed right in your Objective-C code:
\nkill -9 YourPID<\/em>
\nopen PathToYourApp<\/em><\/code>
\nSomething to be aware of, kill -9<\/code> will immediately terminate your application, without going through the usual applicationWillTerminate:<\/a><\/code> business that happens when an application quits more gracefully.<\/p>\n

- (void) restartOurselves
{
   \/\/$N = argv[N]
   NSString *killArg1AndOpenArg2Script = @\"kill -9 $1 \\n open \\\"$2\\\"\";
   
   \/\/NSTask needs its arguments to be strings
   NSString *ourPID = [NSString stringWithFormat:@\"%d\",
                  [[NSProcessInfo processInfo] processIdentifier]];
   
   \/\/this will be the path to the .app bundle,
   \/\/not the executable inside it; exactly what `open` wants
   NSString * pathToUs = [[NSBundle mainBundle] bundlePath];
   
   NSArray *shArgs = [NSArray arrayWithObjects:@\"-c\", \/\/ -c tells sh to execute the next argument, passing it the remaining arguments.
                killArg1AndOpenArg2Script,
                @\"\", \/\/$0 path to script (ignored)
                ourPID, \/\/$1 in restartScript
                pathToUs, \/\/$2 in the restartScript
                nil];
   NSTask *restartTask = [NSTask launchedTaskWithLaunchPath:@\"\/bin\/sh\" arguments:shArgs];
   [restartTask waitUntilExit]; \/\/wait for killArg1AndOpenArg2Script to finish
   NSLog(@\"*** ERROR: %@ should have been terminated, but we are still running\", pathToUs);
   assert(!\"We should not be running!\");
}
<\/code><\/p>\n

WARNING:<\/strong> don’t make the same mistake that I did and test restartOurselves<\/code> without some kind of guard to keep your application from restarting forever. It is very<\/em> difficult to kill such a beast, because whenever it starts up it takes keyboard focus away from what you are doing…. well I’m sure you get the idea<\/a>.<\/p>\n

- (BOOL) weHaveRunBefore {
\n   NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
\n   BOOL weHaveRunBefore = [prefs boolForKey:@\"weHaveRunBefore\"];
\n   [prefs setBool:YESs forKey:@\"weHaveRunBefore\"];
\n   [prefs synchronize];
\n   return weHaveRunBefore;
\n}
\n<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"

Restarting your own application is a tricky thing to do, because you can’t tell yourself to start up when you aren’t running. Here is one solution, use NSTask to run a very short script that you can embed right in your Objective-C code: kill -9 YourPID open PathToYourApp Something to be aware of, kill -9 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18,6,3,5,4,9],"tags":[199,197,198],"class_list":["post-149","post","type-post","status-publish","format-standard","hentry","category-bug-bite","category-cocoa","category-macosx","category-objective-c","category-programming","category-unix","tag-bash","tag-nstask","tag-nsuserdefaults"],"_links":{"self":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/149","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/comments?post=149"}],"version-history":[{"count":0,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/posts\/149\/revisions"}],"wp:attachment":[{"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/media?parent=149"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/categories?post=149"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vgable.com\/blog\/wp-json\/wp\/v2\/tags?post=149"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}