I'm running Ubuntu 22.04.5 LTS (Jammy), Gnome v42.9, which was installed as an upgrade from Ubuntu 19.10 LTS (Eoan Ermine). I installed 22.04.5 in a new partition on the hard drive, leaving 19.10 in its separate partition. I migrated one software application - PDFStudion2019 (by Qoppa) from 19.10 to 22.04.5 (both Ubuntu versions have the software in their separate partitions). Given I installed PDFStudio2019 6 years ago, I have forgotten if I used GitHub or a different repository (for either 19.10 or 22.04.5).
Today, I need to uninstall PDFStudio2019 so I can upgrade to/install PDFStudio2024 Pro. I have tried all the apt commands to uninstall/purge PDFStudion2019. Each command yields the error "Cannot locate package". If I use apt to search for PDFStudio2019, it does not show up in the results - and I have updated apt to the most current repositories, including Main, Universe, Restricted and Multiverse. I am not surprised by this as the software package did not originate in the apt repositories. There is an 'Uninstall' file in PDFStudio2019, which I have run via terminal and via the Uninstall file itself. Both processes show 'activity' in removing the software. But, when they are finished, PDFStudio2019 is still an active piece of software, still located in the same folders, etc.
My question is - how do I uninstall it, if no terminal commands can 'see' the software? I can enter a search command with the exact file location (i.e., /usr/local/pdfstudion2019), and terminal returns "Cannot Locate Package". PDFStudio2019 does not show up in the list of apps when I open Ubuntu Sofware - Installed, but the icon exists on my Taskbar and can be found via Files.
Thanks for any advice you can send my way. I may just need to wipe the 19.10 partition, then install Ubuntu 25.04 Plucky Puffin in its place, then install the new version of PDFStudio2024 Pro.
Paul
Edit as of June 25, 2025 1951 PDT hrs I believe my question(s) is/are different in that the suggested link/answer is dealing with packages which have known names, and that question is referring to the best practice/best method of removing the known package and any related dependencies.
My situation is different - I can see an application is 'installed', I can use it, I can locate it via Files, etc. But when I use any method to locate the application's 'package' (including typing the exact path as shown in Files, all cases correct, all spelling/punctuation/etc. correct), Ubuntu Software and Terminal cannot locate/find the 'application package'. This means no matter what command I use in Terminal, it always returns a "Cannot Locate Package" error. Hence, I cannot remove the 'package'.
To rephrase my questions: 1 - If an application was installed without using apt or dpkg, is there a way to find such 'installed' applications via Terminal? 2 - If such an 'installed' application can be found, are there any commands in Terminal which would allow me to remove it, along with any unnecessary dependents?
Update on pdfstudio2019 file info: Using the "which (package name)" command, I did locate an executable file for pdfstudio - it is located at usr/local/bin/pdfstudio2019. I believe this implies the application was not installed with apt or dpkg, but was via some other compiler or method. The usr/local/bin/pdfstudio2019 file mentions "install4j.com.qoppa.pdfStudio.pub.PDFStudio" twice as noted in the copied text (beginning at line 493 and ending at line 503 in TextEditor):
return_code=0 if [ "$has_space_options" = "true" ]; then $INSTALL4J_JAVA_PREFIX exec "$app_java_home/bin/java" "-splash:$app_home/.install4j/s_oxct2t.png" "$vmov_1" "$vmov_2" "$vmov_3" "$vmov_4" "$vmov_5" $INSTALL4J_ADD_VM_PARAMS -classpath "$local_classpath" install4j.com.qoppa.pdfStudio.pub.PDFStudio "$@" return_code=$? else $INSTALL4J_JAVA_PREFIX exec "$app_java_home/bin/java" "-splash:$app_home/.install4j/s_oxct2t.png" $INSTALL4J_ADD_VM_PARAMS -classpath "$local_classpath" install4j.com.qoppa.pdfStudio.pub.PDFStudio "$@" return_code=$? fi exit $return_code
Update June 26 2025 0951 PDT hrs Guiverc - Thank you for the advice on how to deal with this. Given I don't remember the installation process from 6 or7 years ago, I'll most likely move forward with a clean/new install of Ubuntu 25.04, then a clean (and documented!) install of PDFStudio2024 Pro.
I consider these questions answered.
