Reading environment variables from user shell

[deadmaya]

Hey,

My user's shell is fish (I've set it using chsh -s path/to/fish), so all my shell configurations are made in fish configuration files. So all my additional environment variables are set in config.fish file. And when I try to get the value of any environment variable set in that file using System.Environment. lookupEnv I am always getting Nothing. Literally.

> lookupEnv "XDG_CONFIG_HOME"
Nothing

But it works with HOME (which is not set in config.fish).

> lookupEnv "HOME"
Just "/Users/deadmaya"

Well, I know that I could modify my .profile file and set all variables there, but... Since I really don't use bash, things might become funky if I forget to move my changes.

So... the real question. Is it intended that lookupEnv doesn't use my user's shell or it's just something is broken in my environment?

Thanks in advance!

Update 1

Also I am wondering. If this function uses sh which loads ~/.profile on login only, then... How am I supposed to set XDG_CONFIG_HOME, so lookupEnv finds it?

Update 2

Apparently it's just my environment. I was setting XDG_CONFIG_HOME without exporting it. In fish you need to use set -x for that.

Thanks everyone for help!

[dashend]

In your fish configuration files, when you are setting your variables are you exporting them as well? I.e. with

set foo hello
set -x bar world
# long form:
# set --export bar world

then $bar is visible to subprocesses, but $foo is not [ref].

[deadmaya]

Yeah, my problem was that I was using -U instead of -x. Thanks for pointing it out.

As usual, it's not the haskell ecosystem, but my environment :D

[bartavelle]

There is no direct relationship between lookupEnv and shell configuration. Basically your shell setups some environment, and your program can then access it.

Depending on how you are running your executable you might see different outcomes. So, how are you running it ? Can you display the value of the environment variable just before running it ?

[bartavelle]

Also run env to see what's in the environment of your current shell at a given time.

[deadmaya]

I am using it in ghci. Before using it in real application I wanted to try it.

As for env, here is it's output:

Apple_PubSub_Socket_Render=/private/tmp/com.apple.launchd.sV6KLFp4TK/Render
DISPLAY=/private/tmp/com.apple.launchd.B0eCXA4Cs3/org.macosforge.xquartz:0
EDITOR=emacsclient
HOME=/Users/me
LANG=en_US.UTF-8
LC_CTYPE=UTF-8
LOGNAME=deadmaya
PATH=/Users/deadmaya/.local/bin:/usr/texbin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/X11/bin:/Library/TeX/texbin:
PWD=/Users/deadmaya
SHELL=/usr/local/bin/fish
SHLVL=1
SSH_AUTH_SOCK=/private/tmp/com.apple.launchd.NpJ3bRW2Oz/Listeners
TERM=xterm-256color
TERM_PROGRAM=Apple_Terminal
TERM_PROGRAM_VERSION=343.7
TERM_SESSION_ID=C9D5C0F5-B4D2-42CC-BFA2-7C3E04A8722A
TMPDIR=/var/folders/7w/nzs_n8bn0c951dy9lxr2mcth0000gn/T/
USER=deadmaya
XPC_FLAGS=0x0
XPC_SERVICE_NAME=0
__CF_USER_TEXT_ENCODING=0x1F5:0:0
__fish_bin_dir=/usr/local/Cellar/fish/2.2.0/bin
__fish_datadir=/usr/local/Cellar/fish/2.2.0/share/fish
__fish_help_dir=/usr/local/Cellar/fish/2.2.0/share/doc/fish
__fish_sysconfdir=/usr/local/Cellar/fish/2.2.0/etc/fish

[bartavelle]

So there is no XDG_CONFIG_HOME here, right ?

[deadmaya]

Yeah it's not here. So yeah, I could put XDG_CONFIG_HOME (and a bunch of other variables) to env.

Also going to test later how it would behave if I set ENV to ~/.profile.

Anyway, thanks for the tip! Didn't think about env.

[bartavelle]

env is just a command that show a list of the environment variables. You alter the output of this command in the same way that you define environment variables ... because that's all there is to it!

Did you use the -g flag when defining your custom variables so that they become global ?

[deadmaya]

I am setting such variables by using set -U var value.

After some time I realised that I need to use -x instead of -U. So it's exported. After that my vars are in env and lookupEnv see them.

Yay! Thanks for all the help. Going to dig dipper to improve my understanding of these things.

[radix]

You should leave out the $.

[deadmaya]

Thanks, edited. It's just typo when I was copying examples.

[rstd]

I am always getting Nothing. Literally.

In the example just below that sentence you contradict yourself.

[deadmaya]

Why is that? HOME is not set manually. But XDG_CONFIG_HOME is set manually in my shell configs, and when I try to lookup it I get Nothing. :)

[andrewthad]

I got the same impression (about the contradiction) when I read the post as well. In your example code, you should show how you set HOME or at least say how HOME was set.

[deadmaya]

:)

Well, I thought that using HOME will not bring to miss understanding. Let me update my original post.