Package Management

Install / remove / search package
Show package files / versions
Debian/apt primary; RHEL/dnf notes

Must-know cold

Debian/Ubuntu:

sudo apt update · sudo apt install PKG · apt search KEY · apt show PKG
dpkg -l · dpkg -L PKG · which / command -v after install

RHEL/Fedora/CentOS:

sudo dnf install PKG · dnf search KEY · rpm -ql PKG

Always update the index before install on apt systems.

Debian / Ubuntu

`apt`

Definition: Debian/Ubuntu high-level package manager (install, update, search). Preferred interactively.

Option / verb	Argument	Meaning	Example
`update`	—	Refresh package index from repos	`sudo apt update`
`upgrade`	—	Upgrade installed packages; may install new deps; never removes	`sudo apt upgrade`
`full-upgrade`	—	Like upgrade but may remove packages (same idea as `apt-get dist-upgrade`)	`sudo apt full-upgrade`
`install`	`PKG...`	Install package(s)	`sudo apt install nginx`
`install`	`PKG=VER`	Exact Debian version string (`1.2.3-1ubuntu2`, not just `1.2.3`)	`sudo apt install pkg=1.2.3-1`
`remove`	`PKG`	Remove package; keep dpkg conffiles (usually `/etc`)	`sudo apt remove nginx`
`purge`	`PKG`	Remove package and those conffiles — not `/var` data or logs	`sudo apt purge nginx`
`autoremove`	—	Remove unused dependencies	`sudo apt autoremove`
`search`	`KEY`	Search package names/descriptions	`apt search nginx`
`show`	`PKG`	Details of the candidate in the cache (not always the installed version)	`apt show nginx`
`list`	`--installed`	List installed	`apt list --installed`
`list`	`--upgradable`	Pending upgrades	`apt list --upgradable`
`policy`	`PKG`	Candidate versions / priorities	`apt policy nginx`
`edit-sources`	—	Open sources list (careful)	`sudo apt edit-sources`
`-y`	—	Assume yes on prompts	`sudo apt install -y htop`
`--no-install-recommends`	—	Leaner install	`sudo apt install --no-install-recommends pkg`
`clean`	—	Clear downloaded .deb cache	`sudo apt clean`
`autoclean`	—	Remove obsolete cache debs	`sudo apt autoclean`

Flag combos

Combo	Meaning	Example
`sudo apt update && sudo apt install -y PKG`	Refresh then install	Standard
`apt show PKG \| grep -i version`	Quick version

`apt-get`

Definition: Classic Debian package tool; common in scripts and CI.

Option / verb	Argument	Meaning	Example
`update`	—	Refresh index	`sudo apt-get update`
`install`	`PKG`	Install	`sudo apt-get install -y pkg`
`remove` / `purge`	`PKG`	Remove / purge	`sudo apt-get purge pkg`
`upgrade`	—	Upgrade without installing new packages or removals	`sudo apt-get upgrade`
`dist-upgrade`	—	Smart upgrade (can add and remove); same class as `apt full-upgrade`	`sudo apt-get dist-upgrade`
`download`	`PKG`	Download .deb only	`apt-get download pkg`
`-y`	—	Non-interactive yes	CI
`-qq`	—	Quieter	Scripts

Flag combos

Combo	Meaning	Example
`DEBIAN_FRONTEND=noninteractive apt-get install -y pkg`	CI noninteractive	Containers

`dpkg`

Definition: Install/query .deb packages at a low level (no dependency resolver).

Option	Argument	Meaning	Example
`-i`	`FILE.deb`	Install local deb	`sudo dpkg -i pkg.deb`
`-r`	`PKG`	Remove	`sudo dpkg -r pkg`
`-P`	`PKG`	Purge	`sudo dpkg -P pkg`
`-l`	—	List dpkg records (`ii` installed, `rc` removed-but-config)	`dpkg -l \| grep nginx`
`-l`	`PKG`	Status glob (any output ≠ installed — look for `ii`)	`dpkg -l nginx`
`-L`	`PKG`	List files owned by PKG	`dpkg -L nginx`
`-S`	`PATH`	Which package owns PATH	`dpkg -S /usr/bin/nginx`
`-c`	`FILE.deb`	List contents of deb	`dpkg -c pkg.deb`
`-I`	`FILE.deb`	Deb package info	`dpkg -I pkg.deb`
`--configure`	`-a`	Configure unpacked packages	`sudo dpkg --configure -a`
`--get-selections`	—	Selection states	Backup-ish

Flag combos

Combo	Meaning	Example
`dpkg -i deb; sudo apt-get install -f`	Fix deps after local deb
`dpkg -L pkg \| head`	Where files landed

RHEL family

`dnf`

Definition: Modern RPM-based package manager (install, search, upgrade). Fedora, RHEL 8+, CentOS Stream.

Option / verb	Argument	Meaning	Example
`install`	`PKG`	Install	`sudo dnf install nginx`
`remove`	`PKG`	Remove	`sudo dnf remove nginx`
`upgrade` / `update`	—	Refresh metadata if stale and upgrade (aliases in dnf)	`sudo dnf upgrade`
`search`	`KEY`	Search	`dnf search nginx`
`info`	`PKG`	Details	`dnf info nginx`
`list installed`	—	Installed packages	`dnf list installed`
`provides`	`PATH/CMD`	Which repo package owns that file (installed or not). Often a glob	`dnf provides '*/nproc'`
`repolist`	—	Enabled repos	`dnf repolist`
`clean all`	—	Clean cache	`sudo dnf clean all`
`-y`	—	Assume yes	`sudo dnf install -y htop`
`--setopt=install_weak_deps=False`	—	Fewer weak deps	Lean installs

Flag combos

Combo	Meaning	Example
`sudo dnf install -y PKG`	Parallel to apt install

`yum`

Definition: Legacy RPM package manager (older RHEL/CentOS 7). Prefer dnf when available.

Same verbs mostly: yum install, yum remove, yum search, yum info, yum provides.

`rpm`

Definition: Low-level RPM package query/install/verify tool.

Option	Argument	Meaning	Example
`-ivh`	`FILE.rpm`	Install verbose hash	`sudo rpm -ivh p.rpm`
`-Uvh`	`FILE.rpm`	Upgrade or install. Will not downgrade (use `--oldpackage`)	`sudo rpm -Uvh p.rpm`
`-e`	`PKG`	Erase	`sudo rpm -e pkg`
`-qa`	—	Query all installed	`rpm -qa \| grep nginx`
`-qi`	`PKG`	Package info	`rpm -qi nginx`
`-ql`	`PKG`	List files	`rpm -ql nginx`
`-qf`	`PATH`	Owning package	`rpm -qf /usr/bin/ls`
`-V`	`PKG`	Verify files	`rpm -V nginx`

Flag combos

Combo	Meaning	Example
`rpm -ql pkg \| head`	File list	Like `dpkg -L`

Cross-distro map

Task	Debian/Ubuntu	RHEL family
Refresh + install	`apt update && apt install pkg`	`dnf install pkg`
Search	`apt search`	`dnf search`
Info	`apt show` / `dpkg -l`	`dnf info` / `rpm -qi`
Files in pkg	`dpkg -L pkg`	`rpm -ql pkg`
Who owns installed file	`dpkg -S path`	`rpm -qf path`
Who provides a file (repos)	`apt-file search` (extra)	`dnf provides '*/cmd'`
Remove config too	`apt purge`	often manual conf left

Common recipes

Goal	Command
Install tool (Debian)	`sudo apt update && sudo apt install -y curl jq htop`
Is package installed?	`dpkg -s nginx` (Status: install ok installed) or `dpkg -l nginx` and look for `ii`
Files of package	`dpkg -L nginx \| head`
Who owns binary	`dpkg -S $(which nginx)`
Fix interrupted dpkg	`sudo dpkg --configure -a` · `sudo apt -f install`
Install (RHEL)	`sudo dnf install -y nginx`
Provides command	`dnf provides '*/nproc'`
Clean apt cache (disk)	`sudo apt clean`

Pitfalls

apt install without update can miss packages or install a stale candidate. dnf install refreshes metadata itself (subject to metadata_expire).
apt show / apt search read the cache (candidate). Installed version is dpkg -s / apt policy. apt-get upgrade will not pull new packages; apt upgrade may.
dpkg -l pkg matching a name is not proof it is installed — first column must be ii. rc = removed, config left.
apt purge only deletes dpkg-tracked conffiles, not /var state or logs.
Mixing dpkg -i with no resolver leaves “unconfigured” packages — sudo apt -f install (and dpkg --configure -a).
rpm -qf only sees installed files. dnf provides searches repos (globs like */nproc).
rpm -i/-U do not resolve dependencies — use dnf.
Unattended-upgrades vs manual — know who patches the host.
Third-party repos are a supply-chain risk. State the family from /etc/os-release (apt vs dnf; CentOS 7 is still yum).

For more details, try man <command> in your terminal.

Package Management

Install / remove / search package
Show package files / versions
Debian/apt primary; RHEL/dnf notes

Must-know cold

Debian/Ubuntu:

sudo apt update · sudo apt install PKG · apt search KEY · apt show PKG
dpkg -l · dpkg -L PKG · which / command -v after install

RHEL/Fedora/CentOS:

sudo dnf install PKG · dnf search KEY · rpm -ql PKG

Always update the index before install on apt systems.

Debian / Ubuntu

`apt`

Definition: Debian/Ubuntu high-level package manager (install, update, search). Preferred interactively.

Option / verb	Argument	Meaning	Example
`update`	—	Refresh package index from repos	`sudo apt update`
`upgrade`	—	Upgrade installed packages; may install new deps; never removes	`sudo apt upgrade`
`full-upgrade`	—	Like upgrade but may remove packages (same idea as `apt-get dist-upgrade`)	`sudo apt full-upgrade`
`install`	`PKG...`	Install package(s)	`sudo apt install nginx`
`install`	`PKG=VER`	Exact Debian version string (`1.2.3-1ubuntu2`, not just `1.2.3`)	`sudo apt install pkg=1.2.3-1`
`remove`	`PKG`	Remove package; keep dpkg conffiles (usually `/etc`)	`sudo apt remove nginx`
`purge`	`PKG`	Remove package and those conffiles — not `/var` data or logs	`sudo apt purge nginx`
`autoremove`	—	Remove unused dependencies	`sudo apt autoremove`
`search`	`KEY`	Search package names/descriptions	`apt search nginx`
`show`	`PKG`	Details of the candidate in the cache (not always the installed version)	`apt show nginx`
`list`	`--installed`	List installed	`apt list --installed`
`list`	`--upgradable`	Pending upgrades	`apt list --upgradable`
`policy`	`PKG`	Candidate versions / priorities	`apt policy nginx`
`edit-sources`	—	Open sources list (careful)	`sudo apt edit-sources`
`-y`	—	Assume yes on prompts	`sudo apt install -y htop`
`--no-install-recommends`	—	Leaner install	`sudo apt install --no-install-recommends pkg`
`clean`	—	Clear downloaded .deb cache	`sudo apt clean`
`autoclean`	—	Remove obsolete cache debs	`sudo apt autoclean`

Flag combos

Combo	Meaning	Example
`sudo apt update && sudo apt install -y PKG`	Refresh then install	Standard
`apt show PKG \| grep -i version`	Quick version

`apt-get`

Definition: Classic Debian package tool; common in scripts and CI.

Option / verb	Argument	Meaning	Example
`update`	—	Refresh index	`sudo apt-get update`
`install`	`PKG`	Install	`sudo apt-get install -y pkg`
`remove` / `purge`	`PKG`	Remove / purge	`sudo apt-get purge pkg`
`upgrade`	—	Upgrade without installing new packages or removals	`sudo apt-get upgrade`
`dist-upgrade`	—	Smart upgrade (can add and remove); same class as `apt full-upgrade`	`sudo apt-get dist-upgrade`
`download`	`PKG`	Download .deb only	`apt-get download pkg`
`-y`	—	Non-interactive yes	CI
`-qq`	—	Quieter	Scripts

Flag combos

Combo	Meaning	Example
`DEBIAN_FRONTEND=noninteractive apt-get install -y pkg`	CI noninteractive	Containers

`dpkg`

Definition: Install/query .deb packages at a low level (no dependency resolver).

Option	Argument	Meaning	Example
`-i`	`FILE.deb`	Install local deb	`sudo dpkg -i pkg.deb`
`-r`	`PKG`	Remove	`sudo dpkg -r pkg`
`-P`	`PKG`	Purge	`sudo dpkg -P pkg`
`-l`	—	List dpkg records (`ii` installed, `rc` removed-but-config)	`dpkg -l \| grep nginx`
`-l`	`PKG`	Status glob (any output ≠ installed — look for `ii`)	`dpkg -l nginx`
`-L`	`PKG`	List files owned by PKG	`dpkg -L nginx`
`-S`	`PATH`	Which package owns PATH	`dpkg -S /usr/bin/nginx`
`-c`	`FILE.deb`	List contents of deb	`dpkg -c pkg.deb`
`-I`	`FILE.deb`	Deb package info	`dpkg -I pkg.deb`
`--configure`	`-a`	Configure unpacked packages	`sudo dpkg --configure -a`
`--get-selections`	—	Selection states	Backup-ish

Flag combos

Combo	Meaning	Example
`dpkg -i deb; sudo apt-get install -f`	Fix deps after local deb
`dpkg -L pkg \| head`	Where files landed

RHEL family

`dnf`

Definition: Modern RPM-based package manager (install, search, upgrade). Fedora, RHEL 8+, CentOS Stream.

Option / verb	Argument	Meaning	Example
`install`	`PKG`	Install	`sudo dnf install nginx`
`remove`	`PKG`	Remove	`sudo dnf remove nginx`
`upgrade` / `update`	—	Refresh metadata if stale and upgrade (aliases in dnf)	`sudo dnf upgrade`
`search`	`KEY`	Search	`dnf search nginx`
`info`	`PKG`	Details	`dnf info nginx`
`list installed`	—	Installed packages	`dnf list installed`
`provides`	`PATH/CMD`	Which repo package owns that file (installed or not). Often a glob	`dnf provides '*/nproc'`
`repolist`	—	Enabled repos	`dnf repolist`
`clean all`	—	Clean cache	`sudo dnf clean all`
`-y`	—	Assume yes	`sudo dnf install -y htop`
`--setopt=install_weak_deps=False`	—	Fewer weak deps	Lean installs

Flag combos

Combo	Meaning	Example
`sudo dnf install -y PKG`	Parallel to apt install

`yum`

Definition: Legacy RPM package manager (older RHEL/CentOS 7). Prefer dnf when available.

Same verbs mostly: yum install, yum remove, yum search, yum info, yum provides.

`rpm`

Definition: Low-level RPM package query/install/verify tool.

Option	Argument	Meaning	Example
`-ivh`	`FILE.rpm`	Install verbose hash	`sudo rpm -ivh p.rpm`
`-Uvh`	`FILE.rpm`	Upgrade or install. Will not downgrade (use `--oldpackage`)	`sudo rpm -Uvh p.rpm`
`-e`	`PKG`	Erase	`sudo rpm -e pkg`
`-qa`	—	Query all installed	`rpm -qa \| grep nginx`
`-qi`	`PKG`	Package info	`rpm -qi nginx`
`-ql`	`PKG`	List files	`rpm -ql nginx`
`-qf`	`PATH`	Owning package	`rpm -qf /usr/bin/ls`
`-V`	`PKG`	Verify files	`rpm -V nginx`

Flag combos

Combo	Meaning	Example
`rpm -ql pkg \| head`	File list	Like `dpkg -L`

Cross-distro map

Task	Debian/Ubuntu	RHEL family
Refresh + install	`apt update && apt install pkg`	`dnf install pkg`
Search	`apt search`	`dnf search`
Info	`apt show` / `dpkg -l`	`dnf info` / `rpm -qi`
Files in pkg	`dpkg -L pkg`	`rpm -ql pkg`
Who owns installed file	`dpkg -S path`	`rpm -qf path`
Who provides a file (repos)	`apt-file search` (extra)	`dnf provides '*/cmd'`
Remove config too	`apt purge`	often manual conf left

Common recipes

Goal	Command
Install tool (Debian)	`sudo apt update && sudo apt install -y curl jq htop`
Is package installed?	`dpkg -s nginx` (Status: install ok installed) or `dpkg -l nginx` and look for `ii`
Files of package	`dpkg -L nginx \| head`
Who owns binary	`dpkg -S $(which nginx)`
Fix interrupted dpkg	`sudo dpkg --configure -a` · `sudo apt -f install`
Install (RHEL)	`sudo dnf install -y nginx`
Provides command	`dnf provides '*/nproc'`
Clean apt cache (disk)	`sudo apt clean`

Pitfalls

apt install without update can miss packages or install a stale candidate. dnf install refreshes metadata itself (subject to metadata_expire).
apt show / apt search read the cache (candidate). Installed version is dpkg -s / apt policy. apt-get upgrade will not pull new packages; apt upgrade may.
dpkg -l pkg matching a name is not proof it is installed — first column must be ii. rc = removed, config left.
apt purge only deletes dpkg-tracked conffiles, not /var state or logs.
Mixing dpkg -i with no resolver leaves “unconfigured” packages — sudo apt -f install (and dpkg --configure -a).
rpm -qf only sees installed files. dnf provides searches repos (globs like */nproc).
rpm -i/-U do not resolve dependencies — use dnf.
Unattended-upgrades vs manual — know who patches the host.
Third-party repos are a supply-chain risk. State the family from /etc/os-release (apt vs dnf; CentOS 7 is still yum).

For more details, try man <command> in your terminal.