Strange problem when re-launching an application

Question

I have this program which can self-update to the latest version. What it does is downloads the new version of itself, deletes the old version, renames the new version, sets its permissions and executes it.
Up until this next point, everything worked fine.
The method it executes it is using the Unix style exec() functions.
Until recently, my app was run "Unix Style", as in some kind of login script ran it. There were a lot of issues the cropped up, so I changed it to a proper application package. You know, with the .app directory structure with the real executable inside the MacOS directory.
Now what happens is that the initial app launches and seems to run normally, but when an update comes down, it goes through its update process and launches the replacement with the exec() functions.
Then something strange happens. My app will run for a few more seconds, and then just stop. It will disappear from the task viewer. It does not crash, it just goes away without any explanation.
I have put a lot of logging statements in, and there is no reason for it to stop where it does. I do not even think it stops at the same place. In once caase it stopped between to logging statements. IE: Log statement #1 was in my log file, but no log statement #2 when there was nothing in the world that could have caused the program to exit between them.
Does anyone know why this happens?
I have a suspicion, that maybe the fact that I am using the Unix exec command to launch the app, it is causing some trouble and I need to use the apple method.
What is the API command to launch another executable in a manner that it would be launched by the login window aka a user double clicking on the app icon?

Answer 1

First of all, have you set a proper bundle identifier for your app? It'll be the CFBundleIdentifier entry in the bundle's Info.plist file.
The equivalent to double-clicking on an app in the Finder is probably LSOpenFSRef() which is part of Launch Services:
OSStatus LSOpenFSRef (
const FSRef *inRef,
FSRef *outLaunchedRef
You can change a posix style path to an FSRef (opaque File system reference) using FSPathMakeRef():
OSStatus FSPathMakeRef (
const UInt8 * path,
FSRef * ref,
Boolean * isDirectory
That function is part of the CoreServices framework:
/Developer/SDKs/MacOSX10.4u.sdk/System/Library/Frameworks/CoreServices.framework / .. /Frameworks/CarbonCore.framework/ .. /Headers/Files.h"
Hope this helps....
Dual 2.7GHz PowerPC G5 w/ 2.5 GB RAM; 17" MacBook Pro w/ 2 GB RAM -   Mac OS X (10.4.8)