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Issue with executing a command

3 posts

1marc1#

Issue with executing a command

Hi Team,

For a number of evenings I have been struggling with the following.

One of the things my installer does is it installs a Ruby gem. Prior to the installation, I want to remove all versions of the gem so that I can be sure only the specific version is running on the user's system.

To accomplish this, I have been trying lots of different things, but none are working.

When uninstalling manually, all I need to do is run: 
C:\Ruby25-x64\bin\gem.cmd uninstall MyGem -a -I -x
The issue is that some users may be running Ruby version 2.6.x, others are on 2.7.x. Therefore the path to the `gem.cmd` changes.

I have created a macro that determines the correct path on the user's system to the `gem.cmd` file. This macro sets the value of the GEMCMD variable. This works fine.

The problem comes when I try to instruct NSIS to execute the command. I have tried a number of different things, but neither of them uninstalls MyGem.

Please see the code snippet below. The bottom four lines show my latest examples of things that I tried. The first of those works, but has the path hard-coded. The other three don't work.


; The following sets the value of the GEMCMD variable.

!insertmacro DetermineGem



; Message to verify that the gem command is correctly assigned to the variable.

MessageBox MB_OK "Gem command is: $GEMCMD"



ExpandEnvStrings $0 %COMSPEC%

; good: nsExec::ExecToStack '"$0" /C C:\Ruby25-x64\bin\gem.cmd uninstall MyGem -a -I -x'

; bad : nsExec::ExecToStack '"$0" /C $GEMCMD uninstall MyGem -a -I -x'

; bad : nsExec::ExecToStack '"$0" /C "$GEMCMD" uninstall MyGem -a -I -x'

; bad : ExecWait '"$0" "/C" "$GEMCMD" "uninstall" "MyGem" "-a" "-I" "-x"' $0
Thank you in advance for any advice on this.

Marc.
1marc1#
Anders,

I had been looking at the DetailPrint output, but the command was too long to fit in the window. I have now implemented the DumpLog function and reviewed things in the log file it creates. In there I found that the value of $GEMCMD ends in a newline...

I have now implemented the Trim function and things are now working they way I want.

Thanks again for putting me on the right track.

Marc.