326

How to list all variables names and their current values?

Including not only $HOME, $PWD etc but any other you have defined.

454

For bash: (the standard shell in Ubuntu)

Enter the following command in a terminal to print all the environment variables:

printenv

For further information about this command, read the printenv man page.


To show a list including the "shell variables" you can enter the next command:

( set -o posix ; set ) | less

This will show you not only the shell variables, but the environment variables too.

For more information related with this topic read:


For zsh: (an advanced shell)

Use the following command:

( setopt posixbuiltin; set; ) | less

For more information about ZSH options, see zshoptions man page.

  • 13
    If I go to the terminal and write MYNEWVARIABLE=Ubuntu and execute printenv it doesn't show there. Why is that, and how do those others show up? – Strapakowsky Mar 30 '13 at 3:30
  • 4
    Probably you are seeing the difference between a shell variable and an environment variable. Try export MYNEWVARIABLE=Ubuntu and it will work as you expect. – Rmano Oct 12 '13 at 0:41
  • 3
    if you simply execute set, it lists the variable created by you as well. Or do set | grep myvar – Sergiy Kolodyazhnyy Jan 4 '15 at 15:01
  • 4
    printenv is an external command, so it only knows about (and prints) exported environment variables. set is an internal bash command, so it shows all the "shell variables" (unexported environment variables) as well as the exported environment variables. – Dan Pritts Jul 30 '15 at 15:33
  • 1
    To expand on @Rmano's reply to @Strapakowsky... This will not work unset MYNEWVARIABLE; MYNEWVARIABLE=Ubuntu; printenv | grep MYNEW, but this will unset MYNEWVARIABLE; export MYNEWVARIABLE=Ubuntu; printenv | grep MYNEW, and this will unset MYNEWVARIABLE; MYNEWVARIABLE=Ubuntu printenv | grep MYNEW. Using export says "the variable I'm setting should be part of the environment that gets passed to processes, not just a variable in this shell." My third example says "the variable should be part of the environment that gets passed to THIS process, but not stick around afterward." – Bruno Bronosky Aug 26 '16 at 17:39
49

I know that this question is quite old and answered, but I think I can add a bit of useful information.

In all the methods described above, the procedure that is suggested is:

  • launch a terminal
  • show the environment variables using env, or printenv or whatever

The problem of these solutions are that you are seeing the environment variables of the shell that is running into the terminal. You are not seeing the environment variables available to an application run, for example, directly by the graphic interface.

This is noticeable if, for example, you use your ~/.profile, or .bashrc, or .zshenv (depending on your shell) to modify the environment variables --- like the classic addition of directories to the path.

To see the environment variables available to the application started directly in the graphic environment, you can do the following (in Gnome Shell, I am sure there is an equivalent method in all the other DE):

  • press Alt-F2
  • run the command xterm -e bash --noprofile --norc

(Or, if you do not have xterm, gnome-terminal -- bash --noprofile --norc --- thanks to @Mike Nakis for the comment).

You now have a terminal with a shell that did not add any environment variables. You can use env here to list all your environment variables:

Example of the bare shell

Obviously the new shell will have the environment variables added by the system files, but that variables should be available (by inheritance) to all programs in the system anyway.

I am posting this because it's the fourth time I have to search this trick again, checking my .pam_environment file. So now I will find it faster (and in the process, I hope helping someone else...)

  • Requires you have a desktop environment, not useful for server CLI-only folk. – K7AAY Oct 21 '13 at 18:21
  • 4
    Yes --- but then for CLI only the previous answer is ok. I was just pointing out that sometime you need to check environment variables available to application started by the graphical environment, which is not the same set you see when you start a terminal in it. For example, if you are trying to understand why your Kile app can't compile a LaTeX file, while in a terminal you can, the trick I posted here will help a lot. – Rmano Oct 21 '13 at 20:36
  • 3
    Thanks for a very useful answer! I just linked to it from help.ubuntu.com/community/… – Gunnar Hjalmarsson Jan 2 '14 at 17:06
  • Thanks. Did you recommend xterm -e bash --noprofile --norc because the startup files are not read and executed when Ubuntu is started with graphical interface ? See askubuntu.com/q/1025845/1471 – Tim Apr 17 '18 at 14:49
  • 1
    the right command to execute nowadays (Ubuntu 18.04) is gnome-terminal -- bash --noprofile --norc – Mike Nakis Apr 28 at 11:10
36

You can see all variables with the declare builtin.

declare -p

If you're only interested in environment variables, use

declare -xp

Run help declare to see what the other options are.

  • this is far neat-er solution than POSIXLY_CORRECT=1 set and it is also worthy of mention that declare is alias (in that context) for typeset, another bash builtin. – user359096 Feb 7 '18 at 16:50
11

To list the environment variables in terminal with CTRL+ALT+T you can use env command.

for example :

[raja@localhost ~]$ env
XDG_VTNR=1
SSH_AGENT_PID=3671
XDG_SESSION_ID=3
HOSTNAME=localhost.localdomain
IMSETTINGS_INTEGRATE_DESKTOP=yes
GPG_AGENT_INFO=/home/raja/.gnupg/S.gpg-agent:3691:1
GLADE_PIXMAP_PATH=:
TERM=xterm-256color
SHELL=/bin/bash
XDG_MENU_PREFIX=xfce-
DESKTOP_STARTUP_ID=
HISTSIZE=1000
XDG_SESSION_COOKIE=0250277dd805498381e96c05d88068b0-1364679772.845276-1676152201
WINDOWID=65011716
GNOME_KEYRING_CONTROL=/home/raja/.cache/keyring-N3QoQ2
IMSETTINGS_MODULE=none
QT_GRAPHICSSYSTEM_CHECKED=1
USER=raja

etc.

hope that helps.

5

In bash using compgen:

compgen -v | while read line; do echo $line=${!line};done  
  • 1
    This should be the accepted answer, as all others list more than just the name itself. In my case some variables contain multiline values which makes the other solutions not feasable. – Mene Nov 9 '17 at 15:20
  • A variant: compgen -v | while read line; do declare -p $line; done – Eljay Dec 13 '18 at 17:58
2

env is a POSIX 7 way:

export asdf=qwer
env | grep asdf

Sample output:

asdf=qwer

It only shows exported variables: non-exported variables are not usually considered "environment variables".

Prefer that over printenv, which is not POSIX. Both seem to do the same thing without arguments: https://unix.stackexchange.com/questions/123473/what-is-the-difference-between-env-and-printenv

2

If you want a specific environment variable, rather than printing them all with printenv, you can for example print it by doing echo "$PWD"

2

Most solutions here either print only environment variables, or have the drawback that env or (set -o posix; posix) do not print values in parseable form (try to print variable A=$'a\r\nb'...).

Here is a function that will print all variables, one variable per line, in the POSIX escaped form:

function dump_vars {
    local VARNAME
    compgen -v | while read -r VARNAME; do
        printf "$VARNAME=%q\n" "${!VARNAME}"
    done
}

Thanks to @tmgoblin for pointing out the use of compgen -v.

  • 1
    Excellent first answer! +1 Keep up the good work! – Fabby Dec 15 '18 at 16:29
0

printenv only lists exported variables, command+alt+$ ( "\e$": complete-variable ) will list all variables.

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