UNIX for Dummies Questions & Answers

Okay, I need some nerd magic here! LOL!

Using a bash script, I have a folder that I'd like to remove upon uninstalling a package. That part is simple but what isn't simple is taking into consideration a 'reinstall' or 'upgrade' of that same package.

By default, 'reinstalling' or 'upgrading' a package runs the 'Install' process as well as the 'Uninstall' process...in that order?!?! I don't know why it's done this way but it is what it is.

Sooo, is there a way for a bash script to identify if a package is 'truly' being uninstalled...not being reinstalled or upgraded? If so, what would this bash script look like?

I'm just pulling at straws here since I'm not good at bash scripting...

Code:

 
#There's more script prior to this...
 
DIR="/private/var/mobile/MYFOLDER"
 
if [ $# -ne 1 ]
then
echo "Usage: $0 {/private/var/mobile/MYFOLDER}"
exit 0
fi
 
#Should it look something like this????? PLEASE HELP
if [ -d "$DIR" ]
elif [[ $1 == uninstall]]; then
rm -r "$DIR"   
fi
 
declare -a cydia
cydia=($CYDIA) 
 
if [[ ${CYDIA+@} ]]; then
        eval "echo 'finish:restart' >&${cydia[0]}" 
fi
 
exit

Thanx in advance!

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Replies will be faster at some times of the day than others. If you don't get a reply immediately, either wait or post more information. Sometimes, people aren't posting because they don't quite know what you want and aren't sure what to ask, either.

What's your system? How do you usually install packages?

I just sent a reply to ur message. I sincerely apologize for violating the rules. My apology. :-(

---------- Post updated at 09:47 AM ---------- Previous update was at 09:44 AM ----------

I'm running Ubuntu but this application is being used in Cydia (iPhone jailbreak community). Thanx again for the reply! Sorry for the trouble...

How is this cydia application typically used? Does it print options when you do cydia --help? I can't find a manual page for it which really limits what I can figure out about it.

I apologize for my ignorance. I'm not sure if a --help page even exists for Cydia.

Cydia is an iPhone application similar to the Apple AppStore which hosts applications (specifically Debian packages). AFAIK, it's Linux-Based. Since it installs Debian packages, each package must have a DEBIAN folder that includes a 'control' file. If desirable, someone could include preinst, postinst, prerm & postrm files using bash script.

My specific bash script is in the postrm file which will initiate a soft-reboot after the uninstall, reinstall, or upgrade is completed.

Not sure if any of that info helps...

It helps a fair bit actually, since we now know what context your script's being run inside.

What I would do is env > /tmp/cydia-env-$$ which should dump all available variables in the script to a unique temporary file($$ is the process ID, which changes every time). Then check to see if cydia's setting any relevant variables.