Common Pacman commands and how to remember their flags

Two-Level Syntax and Common Flags#

The easiest way to remember pacman is as "two levels of syntax":

pacman -<大类><小参数>

At the first level, learn the four most common operation groups:

• S = Sync: synchronize with repositories / install software
• Q = Query: query software installed locally
• R = Remove: uninstall
• U = Upgrade: install a local package file

These are the essential operations.

Your most frequent everyday commands can be reduced to:

sudo pacman -Syu
sudo pacman -S foo
pacman -Ss foo
pacman -Qs foo
pacman -Qi foo
pacman -Ql foo
pacman -Qo /usr/bin/foo
sudo pacman -Rns foo

The most important distinction to understand is between S and Q:

-S* → 问“仓库里有什么”
-Q* → 问“我电脑上已经有什么”

So:

pacman -Ss firefox

= Search remote repositories for firefox.

pacman -Qs firefox

= Search the firefox-related packages already installed locally.

A Few Easily Confused Commands

pacman -Sy

This only refreshes the database, without upgrading packages. Generally, avoid doing this by itself on Arch, as it can cause a partial upgrade.

Normally, use:

sudo pacman -Syu

One way to memorize it is:

S = Sync
y = refresh repository database
u = upgrade installed packages

In other words:

同步 → 刷新数据库 → 升级

-Rns is also worth committing to muscle memory:

R = Remove
n = nosave，不生成受管理配置的 .pacsave 备份
s = 顺便删无用依赖

Before uninstalling, confirm that you no longer need the software and decide whether to retain .pacsave configuration backups:

sudo pacman -Rns foo

Orphaned Dependencies and File Checks#

The following commands are useful for troubleshooting:

pacman -Qdt

Find orphaned dependencies. Remember it as:

Q = query
d = dependency
t = unrequired

Inspect the query results first. Packages you still need should be marked as explicitly installed. For removal, specify only package names you have confirmed are no longer needed:

sudo pacman -Rns <CONFIRMED_ORPHAN_PACKAGE>

And:

pacman -Qk foo

Check whether any files installed by a package are missing; k = check.

pacman -Qkk foo

Perform a more detailed check.

Flag Compatibility in AUR Helpers#

If you use paru, most pacman query and installation flags work unchanged:

paru -S foo
paru -Ss foo
paru -Qs foo
paru -Syu

The simplest mental map is:

pacman
├── S  仓库 / 安装
│   ├── s search
│   ├── i info
│   └── yu 更新
├── Q  本机查询
│   ├── s search
│   ├── i info
│   ├── l list files
│   └── o owner
├── R  卸载
│   └── ns 干净卸载
└── U  本地 pkg.tar.zst

S / Q / R / U provide a starting point for memorization. For removal and cache cleanup, still review the confirmation list and the current manual. -n does not erase all settings in a user's home directory.