If running as a normal (non-root) user, you will often find that permission is denied. To demand that a command be granted permissions, preface it with sudo.
apt-get update W: chmod 0700 of directory /var/lib/apt/lists/partial failed - SetupAPTPartialDirectory (1: Operation not permitted) E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied) E: Unable to lock directory /var/lib/apt/lists/ W: Problem unlinking the file /var/cache/apt/pkgcache.bin - RemoveCaches (13: Permission denied) W: Problem unlinking the file /var/cache/apt/srcpkgcache.bin - RemoveCaches (13: Permission denied) E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root? sudo apt-get update [sudo] password for jenny:
You enter your password...
Doing this requires sudo privileges. Add a user to the sudo group with:
gpasswd -a jenny sudo
You can make LibreOffice (for example) work with sudo without requiring a password by adding this line to you sudoers file:
users ALL=(ALL) NOPASSWD: libreoffice
Allowing sudo to libreoffice for everyone without password is opening a can of worms. Please beware of the consequences, including the possibility to acquiring root permissions on a multi-user platform