Linux Software Package

From KevinWiki

Check Package

$ dpkg -l | grep <package name>

$ apt-cache policy <package name>

$ apt-cache search <package name in regular expression>

Lock Version

• Lock the current version of a package (so it will not be upgraded)

sudo apt-mark hold package_name 

• Unlock the locked package.

sudo apt-mark unhold package_name 

Troubleshooting

After run apt-get update if there is a GPG error like

W: GPG error: http://ppa.launchpad.net lucid Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 608BF7B93528AE20

Take the last 8 characters from the keyid

e.g.)
from the keyid
608BF7B93528AE20
take 3528AE20

Run the following commands

gpg --keyserver keyserver.ubuntu.com --recv 3528AE20
gpg --export --armor 3528AE20 | sudo apt-key add -

OR Use the full keyid and put the 0x before it then run the following commands

wget -q "http://keyserver.ubuntu.com:11371/pks/lookup?op=get&search=0x608BF7B93528AE20" -O- | sudo apt-key add -

If it does not work, remove the port number and try again.

wget -q "http://keyserver.ubuntu.com/pks/lookup?op=get&search=0x608BF7B93528AE20" -O- | sudo apt-key add -

To see all the keys,

sudo apt-key list