Where does a .deb file go after installation?

Question

I just installed Dolphin 4.0 from a .deb file, where is the application OR how do I access it?

Answer 1

DEB file is actually an archive with control information telling dpkg what to do with those files and other stuff ans Zacharee1 has already said. In addition to his answer, you can check where a deb file goes by using this command (after installation)

dpkg -L package-name

If the deb file name is dolphin_3.23_amd64.deb, the first part before _ is the package name.

This is the output of dolphin package

→ dpkg -L dolphin
/.
/etc
/etc/xdg
/etc/xdg/servicemenu.knsrc
/usr
/usr/bin
/usr/bin/dolphin
/usr/bin/servicemenuinstallation
/usr/bin/servicemenudeinstallation
/usr/lib
/usr/lib/x86_64-linux-gnu
/usr/lib/x86_64-linux-gnu/qt5
/usr/lib/x86_64-linux-gnu/qt5/plugins
/usr/lib/x86_64-linux-gnu/qt5/plugins/kcm_dolphingeneral.so
/usr/lib/x86_64-linux-gnu/qt5/plugins/kcm_dolphinviewmodes.so
/usr/lib/x86_64-linux-gnu/qt5/plugins/dolphinpart.so
/usr/lib/x86_64-linux-gnu/qt5/plugins/kcm_dolphinnavigation.so
/usr/lib/x86_64-linux-gnu/qt5/plugins/kcm_dolphinservices.so
/usr/lib/x86_64-linux-gnu/libkdeinit5_dolphin.so
/usr/lib/x86_64-linux-gnu/libdolphinprivate.so.5.0.0
/usr/share
/usr/share/doc
/usr/share/doc/dolphin
/usr/share/doc/dolphin/copyright
/usr/share/doc/HTML
/usr/share/doc/HTML/en
/usr/share/doc/HTML/en/dolphin
/usr/share/doc/HTML/en/dolphin/locationbar-breadcrumb.png
/usr/share/doc/HTML/en/dolphin/preferences-startup.png
/usr/share/doc/HTML/en/dolphin/index.cache.bz2
/usr/share/doc/HTML/en/dolphin/nepomuk-search.png
/usr/share/doc/HTML/en/dolphin/viewproperties-dialog.png
/usr/share/doc/HTML/en/dolphin/preferences-services.png
/usr/share/doc/HTML/en/dolphin/locationbar-context-menu.png
/usr/share/doc/HTML/en/dolphin/preferences-general-behavior.png
/usr/share/doc/HTML/en/dolphin/locationbar-editable.png
/usr/share/doc/HTML/en/dolphin/toolbar-navigation.png
/usr/share/doc/HTML/en/dolphin/grouping-view.png
/usr/share/doc/HTML/en/dolphin/preferences-viewmodes-icons.png
/usr/share/doc/HTML/en/dolphin/locationbar-places-icon.png
/usr/share/doc/HTML/en/dolphin/toolbar-view-appearance.png
/usr/share/doc/HTML/en/dolphin/nepomuk-search-more-options.png
/usr/share/doc/HTML/en/dolphin/preferences-navigation.png
/usr/share/doc/HTML/en/dolphin/default-ui.png
/usr/share/doc/HTML/en/dolphin/toolbar.png
/usr/share/doc/HTML/en/dolphin/index.docbook
/usr/share/doc/HTML/en/dolphin/locationbar-kioslaves-menu.png
/usr/share/doc/HTML/en/dolphin/preferences-trash.png
/usr/share/appdata
/usr/share/appdata/org.kde.dolphin.appdata.xml
/usr/share/config.kcfg
/usr/share/config.kcfg/dolphin_generalsettings.kcfg
/usr/share/config.kcfg/dolphin_directoryviewpropertysettings.kcfg
/usr/share/config.kcfg/dolphin_compactmodesettings.kcfg
/usr/share/config.kcfg/dolphin_detailsmodesettings.kcfg
/usr/share/config.kcfg/dolphin_iconsmodesettings.kcfg
/usr/share/config.kcfg/dolphin_versioncontrolsettings.kcfg
/usr/share/applications
/usr/share/applications/org.kde.dolphin.desktop
/usr/share/kxmlgui5
/usr/share/kxmlgui5/dolphinpart
/usr/share/kxmlgui5/dolphinpart/dolphinpart.rc
/usr/share/kxmlgui5/dolphin
/usr/share/kxmlgui5/dolphin/dolphinui.rc
/usr/share/lintian
/usr/share/lintian/overrides
/usr/share/lintian/overrides/dolphin
/usr/share/kservicetypes5
/usr/share/kservicetypes5/fileviewversioncontrolplugin.desktop
/usr/share/dbus-1
/usr/share/dbus-1/services
/usr/share/dbus-1/services/org.kde.dolphin.FileManager1.service
/usr/share/kservices5
/usr/share/kservices5/kcmdolphinservices.desktop
/usr/share/kservices5/dolphinpart.desktop
/usr/share/kservices5/kcmdolphinnavigation.desktop
/usr/share/kservices5/kcmdolphingeneral.desktop
/usr/share/kservices5/kcmdolphinviewmodes.desktop
/usr/lib/x86_64-linux-gnu/libdolphinprivate.so.5
/usr/share/doc/dolphin/changelog.Debian.gz

After installing a deb file, the generated files that went to bin directory can usually be executed. Here we can see 1 entry /usr/bin/dolphin, which means you can use dolphin command to summon it.

Answer 2

DEB files just contain the packaged application, along with some identifiers to tell the OS that it's a DEB, and a few instructions for installation. If you open a DEB and browse it, you'll likely find files under the paths where they'll end up once the DEB is installed.

To open a DEB file you installed, assuming it is one that can be opened, you can either run the command for it in the terminal (Dolphin's is probably dolphin) or search for it. First, though, you should reboot. Sometimes the app isn't indexed until reboot, so you won't see an icon for it.