update vs. upgrade

zaivala · 03-02-2018, 04:30 AM

I know that apt-get update updates the packages you currently have, and apt-get upgrade gets you the latest versions of the packages you have... I cannot find whether upgrade INCLUDES update. In other words, do you have to do update after doing upgrade? Does upgrade only affect packages which have version upgrades?

I'm thinking upgrade should be inclusive, or some command should be inclusive, to do all updates and upgrades at the same time, perhaps upgrades first...

jsbjsb001 · 03-02-2018, 04:53 AM

Quote:

Originally Posted by zaivala

I know that apt-get update updates the packages you currently have, and apt-get upgrade gets you the latest versions of the packages you have... I cannot find whether upgrade INCLUDES update. In other words, do you have to do update after doing upgrade? Does upgrade only affect packages which have version upgrades?

I'm thinking upgrade should be inclusive, or some command should be inclusive, to do all updates and upgrades at the same time, perhaps upgrades first...

Maybe have a look at this - look under "Maintenance commands".

wpeckham · 03-02-2018, 05:40 AM

Quote:

Originally Posted by zaivala

I know that apt-get update updates the packages you currently have, and apt-get upgrade gets you the latest versions of the packages you have... I cannot find whether upgrade INCLUDES update. In other words, do you have to do update after doing upgrade? Does upgrade only affect packages which have version upgrades?

I'm thinking upgrade should be inclusive, or some command should be inclusive, to do all updates and upgrades at the same time, perhaps upgrades first...

Your understanding is not quite correct.

Code:

apt-get update

will only update the DATABASE of package versions available.

Code:

apt-get upgrade  or
apt-get dist-upgrade

will USE that data to bring all of your installed package up to the current available level.

Neither implies the other in any way.

sundialsvcs · 03-02-2018, 06:43 AM

... and in retrospect maybe they should have used a different subcommand-name ... "'update' what?"

It is ambiguous. But, we're stuck with it now.

Shadow_7 · 03-02-2018, 07:13 AM

$ sudo apt-get update

updates the known list of available packages. Which can include knowledge of upgrades. It does not change anything other than it's "list".

$ sudo apt-get upgrade

will check for updates on the "list", but does not run apt-get update. And will grab those updates and apply them, or tell you nothing that is currently installed has updates.

I normally use them in this way. Given that my american 3rd world telecom is SLOW, super slow by international standards.

$ sudo apt-get update
$ sudo apt-get -d dist-upgrade
$ sudo apt-get update
$ sudo apt-get -d dist-upgrade
$ sudo apt-get dist-upgrade

The 2nd update is to check for any NEW updates since I started downloading the "list" of updates. If it does grab some, I might run it a 3rd time. When the 2nd or more update finds nothing new (as determined by how long it takes / data transfers), then I get and apply the updates.

mr.travo · 03-02-2018, 03:52 PM

I'm sorry for the ignorant question I am about to ask, but wasn't apt-get replaced by the "newer" apt command? Just wondering if there is still a difference. I have been using just apt for the last few months.

Knowledge is power and I have the power of a watch battery right now

T

zaivala · 03-03-2018, 07:30 AM

Some distros have tried to move us to the "new" apt command. I have found that apt-get continues to work as before.

And thank you to all the above for your answers.

hydrurga · 03-03-2018, 07:40 AM

Quote:

Originally Posted by mr.travo

I'm sorry for the ignorant question I am about to ask, but wasn't apt-get replaced by the "newer" apt command? Just wondering if there is still a difference. I have been using just apt for the last few months.

Knowledge is power and I have the power of a watch battery right now

T

There are indeed a few differences.

For example, apt update also lets you know if any packages need upgrading, whereas apt-get update doesn't.

In general, I would advise that you use apt, only reverting to apt-get, apt-cache etc. (apt is intended as a replacement for several applications) if apt doesn't provide the required functionality.

Shadow_7 · 03-03-2018, 02:07 PM

apt-get still works, so no need to relearn things just yet.

ntubski · 03-03-2018, 02:50 PM

man apt:

Code:

SCRIPT USAGE AND DIFFERENCES FROM OTHER APT TOOLS
       The apt(8) commandline is designed as an end-user tool and it may change
       behavior between versions. While it tries not to break backward
       compatibility this is not guaranteed either if a change seems beneficial
       for interactive use.

       All features of apt(8) are available in dedicated APT tools like apt-
       get(8) and apt-cache(8) as well.  apt(8) just changes the default value
       of some options (see apt.conf(5) and specifically the Binary scope). So
       you should prefer using these commands (potentially with some additional
       options enabled) in your scripts as they keep backward compatibility as
       much as possible.