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I want my cron-run reporting script to notify me in case there are updates for my packages. Is the a way to make apt-get give me the list of available updates but don't do anything more?

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9 Answers 9

The -u switch shows a list of packages that are available for upgrade:

# apt-get -u upgrade

From the apt-get man page:

 Show upgraded packages; Print out a list of all packages that are to be upgraded. Configuration Item: APT::Get::Show-Upgraded.
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apt-get -u upgrade --assume-no if you don't want it to ask if you want them installed. Does this on 12.10. –  slm Dec 17 '13 at 3:47
I was hoping this could be done without root –  ThorSummoner Feb 6 at 17:33
apt-get --just-print upgrade

Is not read that easily, below is a perl one liner to parse apt-get's output:

apt-get --just-print upgrade 2>&1 | perl -ne 'if (/Inst\s([\w,\-,\d,\.,~,:,\+]+)\s\[([\w,\-,\d,\.,~,:,\+]+)\]\s\(([\w,\-,\d,\.,~,:,\+]+)\)? /i) {print "PROGRAM: $1 INSTALLED: $2 AVAILABLE: $3\n"}'

This should output something like:

PROGRAM: grub-pc INSTALLED: 1.99-21ubuntu3.1 AVAILABLE: 1.99-21ubuntu3.9

Hopefully it will help someone else,

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just for the laugh: apt-get -s upgrade| awk -F'[][() ]+' '/^Inst/{printf "Prog: %s\tcur: %s\tavail: %s\n", $2,$3,$4}' –  tink May 17 '13 at 3:19

You can run

aptitude -F%p --disable-columns search ~U

or the undocumented

/usr/lib/update-notifier/apt-check -p; echo

Another method using an apt-get simulation:

apt-get -s dist-upgrade | awk '/^Inst/ { print $2 }'
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Take a look at package "apticron":

apticron - Simple tool to mail about pending package updates


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apt-get update && apt-get -s upgrade

will list available updates without actually installing.

First command updates package index files before simulated (thus -s) upgrade is done. "-s" will do a simulated upgrade showing packets that would be installed but will not actually install anything.

On the contrary "-u" instead of "-s" would actually install after confirmation.

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Another option, inspired by enzotib :

aptitude search '~U' | wc -l

This command will use aptitude to output the new packages and then wc to just count the lines.

On a sidenote, I found that enzotib's solution without the single quotes around the ~U didn't work for me. (Wheezy, ZSH, aptitude

Update :

With the new apt you can do now :

apt list --upgradable
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I needed full version information on possible upgrades, so I used a modification of jasonwryan's answer:

apt-get -V -u upgrade

It's simple and IMO reasonably formatted output.

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Jet another on-liner, inspired by this answer:

function a { read input;dpkg -l ${input} | grep " ${input} " | awk '{$1=$2=$3=$4="";print $0}' | sed 's/^ *//';unset input;};{ apt-get --just-print upgrade 2>&1 | perl -ne 'if (/Inst\s([\w,\-,\d,\.,~,:,\+]+)\s\[([\w,\-,\d,\.,~,:,\+]+)\]\s\(([\w,\-,\d,\.,~,:,\+]+)\)? /i) {print "$1 (\e[1;34m$2\e[0m -> \e[1;32m$3\e[0m)\n"}';} | while read -r line; do echo -en "$line $(echo $line | awk '{print $1}' | a )\n"; done;

The output looks like this (colored):

locales (2.13-38+deb7u7 -> 2.13-38+deb7u8) Embedded GNU C Library: National Language (locale) data [support]
linux-headers-3.2.0-4-amd64 (3.2.65-1+deb7u1 -> 3.2.65-1+deb7u2) Header files for Linux 3.2.0-4-amd64
linux-headers-3.2.0-4-common (3.2.65-1+deb7u1 -> 3.2.65-1+deb7u2) Common header files for Linux 3.2.0-4
sudo (1.8.5p2-1+nmu1 -> 1.8.5p2-1+nmu2) Provide limited super user privileges to specific users

If you dont want the short description use this one:

{ apt-get --just-print upgrade 2>&1 | perl -ne 'if (/Inst\s([\w,\-,\d,\.,~,:,\+]+)\s\[([\w,\-,\d,\.,~,:,\+]+)\]\s\(([\w,\-,\d,\.,~,:,\+]+)\)? /i) {print "$1 (\e[1;34m$2\e[0m -> \e[1;32m$3\e[0m)\n"}';} | while read -r line; do echo -en "$line\n"; done;


locales (2.13-38+deb7u7 -> 2.13-38+deb7u8)
linux-headers-3.2.0-4-amd64 (3.2.65-1+deb7u1 -> 3.2.65-1+deb7u2)
linux-headers-3.2.0-4-common (3.2.65-1+deb7u1 -> 3.2.65-1+deb7u2)
sudo (1.8.5p2-1+nmu1 -> 1.8.5p2-1+nmu2)
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Just filter the output of

apt-get update && apt-get -s -V -u upgrade

to have only the preferred information in your log.

Most likely, you'll need the beautiful part after the line


The following packages will be upgraded:


that has few spaces in the beginning.

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Hi and welcome to the site. As it stands, your answer is basically a rehash of existing ones and so does not add anything new. You could improve it by, for example, explaining how to filter the output, adding an explanation of what the various switches do etc. –  terdon Nov 19 '14 at 17:29

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