192

If I use apt-get install -qq mono-devel, I expect it to be quiet except for errors, according to the help:

-qq No output except for errors

Instead I get:

Extracting templates from packages: 100%
Selecting previously unselected package binfmt-support.
(Reading database ... 84711 files and directories currently installed.)
Unpacking binfmt-support (from .../binfmt-support_2.0.8_i386.deb) ...
Selecting previously unselected package cli-common.
Unpacking cli-common (from .../cli-common_0.8.2_all.deb) ...
Selecting previously unselected package libgdiplus.
Unpacking libgdiplus (from .../libgdiplus_2.10-3_i386.deb) ...
Selecting previously unselected package libmono-2.0-1.
Unpacking libmono-2.0-1 (from .../libmono-2.0-1_2.10.8.1-1ubuntu2.2_i386.deb) ...
Selecting previously unselected package libmono-2.0-dev.
Unpacking libmono-2.0-dev (from .../libmono-2.0-dev_2.10.8.1-1ubuntu2.2_i386.deb) ...
Selecting previously unselected package libmono-corlib4.0-cil.
Unpacking libmono-corlib4.0-cil (from .../libmono-corlib4.0-cil_2.10.8.1-1ubuntu2.2_all.deb) ...
Selecting previously unselected package libmono-system-xml4.0-cil.
Unpacking libmono-system-xml4.0-cil (from .../libmono-system-xml4.

and more...

In fact, a couple hundred lines worth of output. This does not appear to match up with no output except for errors.

How do I actually get apt-get install to print out only when there are errors keeping it from installing?

6
  • Have you tried using -q=# where # is a quiet level? (It's in the manual.) You may want to raise a bug report against this. Feb 26, 2013 at 9:26
  • @PaddyLandau I did indeed. I don't know why it's talking about selecting previously unselected package either or why that would be important, and I'm not sure if it's related to the state of the vms I'm running this on these on either, travis-ci. But the answer worked well.
    – jbtule
    Feb 26, 2013 at 13:38
  • "Selecting previously unselected package" simply means that the package manager is including a package required to satisfy dependencies. As I previously wrote, you may want to raise a bug report about the --quiet option appearing not to be working correctly. Feb 26, 2013 at 17:35
  • I'm unhappy to report that same symptom in Ubuntu 15.04 20150709. Aug 7, 2015 at 21:02
  • 2
    Looks like this relates to 2009 dpkg issue report: bugs.debian.org/cgi-bin/bugreport.cgi?bug=539617 . Aug 7, 2015 at 21:18

7 Answers 7

136

The man page for apt-get is as follows:

NAME
       apt-get - APT package handling utility -- command-line interface

SYNOPSIS
       apt-get [-asqdyfmubV] [-o=config_string] [-c=config_file] [-t=target_release]
               [-a=architecture] {update | upgrade | dselect-upgrade | dist-upgrade |
               install pkg [{=pkg_version_number | /target_release}]...  | remove pkg...  |
               purge pkg...  | source pkg [{=pkg_version_number | /target_release}]...  |
               build-dep pkg [{=pkg_version_number | /target_release}]...  |
               download pkg [{=pkg_version_number | /target_release}]...  | check | clean |
               autoclean | autoremove | {-v | --version} | {-h | --help}}

The -q or -qq flag should go before the command, like so:

apt-get -qq upgrade

13
  • 3
    This is the correct answer! Any practical implementation needs to preserve prompts. Used correctly, -q absolutely works (no "animated" output) as well as -qq (no output except errors). Please upvote! Aug 19, 2015 at 19:18
  • 70
    No, it doesn't work. Even with -qq before the install command I still get tons of junk everything from reading database to unpacking and setting up messages.
    – CrazyCasta
    Jun 20, 2016 at 23:55
  • 4
    This is Ubuntu 16.04.1, running as a Docker container. My guess is that the messages are actually from dpkg, which is called by apt-get. The command is apt-get -qq update && apt-get -qq upgrade && apt-get -qq install build-essential. See gist.github.com/stefanlasiewski/… Dec 8, 2016 at 19:13
  • 4
    In Docker you have 2 alternatives: (1) run each command separately rather than with && joining them (might work, but it's not the "docker way") (2) redirect the output to /dev/null like in the other answer. Option 2 is probably your best bet while there is this bug.
    – Mike
    Dec 9, 2016 at 8:44
  • 4
    Same here: I tried putting the -qq before install as well as after install, and both scenarios still resulted in the Unpacking ..., Selecting ..., Preparing ..., etc. messages that I do not want to see. I am using the ubuntu:20.04 Docker container Feb 9, 2022 at 0:15
99

We faced the same problem. apt-get install -qq removes most of the outputs but annoying "(Reading database ..." still persist.

We took a look in the source of apt and discover that the output is produced by dpkg that was forked by apt. Then the source of dpkg shows that the annoying soutput is only issued when isatty(1) is true. This is only the case when the fork uses pty instead pipe. Back to apt, there is a undocumented configuration variable that allows to use pipe instead pty which then solve the problem:

apt-get install -qq -o=Dpkg::Use-Pty=0 <packages>

Expecting that can help others.

15
  • 4
    Actually this is full correct answer. It's also allow to run apt-get with single -q and see some output and don't see annoying "Reading database"
    – valodzka
    Sep 30, 2015 at 20:26
  • 2
    I'm trying this on gcloud debian jessie (8) and I still get reading database lines and unpacking/setting up lines.
    – CrazyCasta
    Jun 21, 2016 at 0:09
  • 6
    This answer does not work for Ubuntu 18.04. May 10, 2018 at 16:06
  • 5
    The -o=Dpkg::Use-Pty=0 worked perfect on Ubuntu 18.04. It only shows one "Reading database" instead of multiple ones with progress updates every 5%.
    – wisbucky
    Jul 18, 2019 at 22:24
  • 4
    It seems that -o=Dpkg::Use-Pty=0 doesn't affect the output in Ubuntu 20.04.
    – alfC
    Mar 15, 2021 at 9:43
66

A simple redirection could do this. It's not exactly what you had in mind, I'm sure, but it sure as hell works :)

In short, just whack > /dev/null on the end of any command where you want to redirect all the stdout into nothingness. Things outputted on stderr will still show in the console.

$ sudo apt-get update > /dev/null
[sudo] password for oli: 
$ 

No junk! And here's what happens if we're silly and break something:

$ apt-get cheese > /dev/null
E: Invalid operation cheese
$
9
  • 10
    That's a bit of a problem if you get a prompt...
    – l0b0
    Feb 19, 2013 at 16:44
  • 1
    If this is part a script, you wouldn't put a sudo in front of apt-get. You would just sudo when running the script instead.
    – Xion
    Feb 19, 2013 at 16:49
  • 7
    @Oli If you're absolutely sure you're not going to make your system catch on fire, you could always sudo apt-get upgrade -qq --force-yes > /dev/null. -qq implies -y, as WulfHart said, and --force-yes makes it plow through just about anything. Feb 26, 2013 at 13:46
  • 2
    @Vorac No it's just redirecting stdout (seeing the errors is a desirable thing IMO).
    – Oli
    Mar 27, 2013 at 13:34
  • 6
    This is not the answer to the question; it's a workaround. Aug 19, 2015 at 19:19
6

As you can see here and here
You can do:

export DEBIAN_FRONTEND=noninteractive
apt-get -yq install [packagename]
export DEBIAN_FRONTEND=dialog

Or one line:

DEBIAN_FRONTEND=noninteractive apt-get -yq install [packagename]
3

With apt-get -qq install -y PACKAGE 2> /dev/null you can:

  1. Show only the errors with -qq.
  2. Send the errors to /dev/null (not show) so with that you can install a package with zero output.
1
  • 2
    This is not what OP is asking. OP explicitly says they want errors to print, whereas this will hide errors Feb 9, 2022 at 0:19
1

For me this works perfectly for fully silent/zero output while installing cause NULL STDIN and STDOUT.

DEBIAN_FRONTEND=noninteractive apt-get install -qq [packagename] < /dev/null > /dev/null

Hope it helps!!

-1

You can use a python script to do literally anything with the stdout and stderr of every command. For example, if you want to see a dynamic output including only the last line of the output, you can use the following script :

#!/usr/bin/python3
import subprocess, sys
process = subprocess.Popen(sys.argv[1:], stdout=subprocess.PIPE)
while process.poll() is None:
  stdout = process.stdout.readline().decode()[:-1]
  print(stdout,end='\r')
print()

If you know how to work with strings in python, you can tweak the script to print only the lines you want to be printed, in whatever format you wish.

Save the above code in a file such as run.py. Then you can run any command to see only the last line of the output dynamically. For example:

./run.py sudo apt-get install <package>

or:

./run.py sudo apt-get update
Note 1: Don't forget to give exec permission to your script:
chmod +x run.py
Note 2: You can make a proper symlink for a more convenient usage (or alternatively add the script path to $PATH environment variable which I do not suggest):
sudo ln -s <path/to/yourscript.py> /usr/bin/run

Afterwards, you can only use:

run <command-with-desired-output-format>

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