krisbg
7th March 2005 18:50 UTC

Return code of uninstaller
Hi!
I want to understand when my installer has found a previous version and has run it's uninstaller, if the user hit the Cancel button in the uninstaller so the current installer to be stopped too. Is there a way to find if the user hit Cancel from the return value?

pengyou
7th March 2005 19:13 UTC

From the NSIS Users Manual (Appendix D - Useful Information):

Error levels:

Like other applications installers made by NSIS return error levels as a result of their execution. Checking the error level can be useful if you call an NSIS installer from another application or installer.

0 - Normal execution (no error)
1 - Installation aborted by user (cancel button)
2 - Installation aborted by script

To find out how to access the uninstaller's error level, read the rest of this section of the manual:
http://nsis.sourceforge.net/Docs/AppendixD.html#D.2

krisbg
8th March 2005 11:45 UTC

Thank You!
It's interesting that in the manual is written that the uninstaller copies itself into the $TEMP folder and executes from there so to be able to get the correct return code you should copy it there manually. But I experimented and saw that even if I don't copy it by myself I still get the correct codes. Does anybody know something about this?

kichik
8th March 2005 19:22 UTC

As of NSIS 2.01, you can set the error level to other values using SetErrorLevel.

If you execute the uninstaller with _?= it will not copy itself and you'll get the real return value.