How to find packages that are not required by other packages and remove them

Installing and Using OpenWrt
1

Like I install install "apk-openssl", need "wget-notsll".

Then I remove "apk-openssl", "wget-notsll" remove too?

Or it may have been automatically removed (unused packages)？

2

Check the reverse dependency first: apk info -r apk-openssl should show what still needs it. If wget-nossl depends on it, a normal apk del apk-openssl should not leave a broken install; it will either refuse or remove the depending package too. For old dependency packages that nothing uses anymore, try apk autoremove rather than deleting by hand.

3

no

ERROR: 'autoremove' is not an apk command. See 'apk --help'

has be remove

4

Use --orphaned.

$ apk list -h | grep orphan
  --orphaned            Filter selection to orphaned packages
  --orphaned, -O        Consider only orphaned packages

$ apk list --orphaned
...

Note that apk normally removes orphaned packages automatically, so there's no need for an autoremove type of applet.