Check if package is installed on Debian
Using dpkg
Query dpkg database to determine if package is installed.
dpkg-query --show --showformat='${db:Status-Status}\n' ca-certificates
if installed
installed
if not installed
dpkg-query: no packages found matching ca-certificates
Using apt
apt-cache policy ca-certificates
if installed
ca-certificates:
Installed: 20230311
Candidate: 20230311
Version table:
*** 20230311 500
500 http://mirrors.linode.com/debian bookworm/main amd64 Packages
100 /var/lib/dpkg/status
if not installed
iperf3:
Installed: (none)
Candidate: 3.12-1+deb12u1
Version table:
3.12-1+deb12u1 500
500 http://mirrors.linode.com/debian bookworm/main amd64 Packages
500 http://mirrors.linode.com/debian-security bookworm-security/updates/main amd64 Packages
100 /var/lib/dpkg/status
Reference
https://sleeplessbeastie.eu/2025/02/25/how-to-determine-if-specific-package-is-installed/
https://www.cyberciti.biz/faq/find-out-if-package-is-installed-in-linux/
https://forums.debian.net/viewtopic.php?t=159341