Show the environment variables of a running process in Linux

Tired of the privacy invasion of the Chrome webbrowser? Worried about the risk of seeing ads everywhere? Give the Brave Browser a try. It supports all the same Chrome extensions, with none of the telemetry. It auto-blocks ads and helps support content creators like me.

Give the Brave browser a try »

Profile image of Mattias Geniar

Mattias Geniar, January 11, 2017

Follow me on Twitter as @mattiasgeniar

A quick mental dump in case I forget it again next time. First, check your PID:

$ ps faux | grep 'your_process'
508   28818  0.0  0.3  44704  3584 ?  Sl   10:10   0:00  \_ /path/to/your/script.sh

Now, using that PID (in this case, 28818), check the environment variables in /proc/$PID/environ.

$ cat /proc/28818/environ
TERM=linuxPATH=/sbin:/usr/sbin:/bin:/usr/binrunlevel=3RUNLEVEL=3SUPERVISOR_GROUP_NAME=xxxPWD=/path/to/your/homedirLANGSH_SOURCED=1LANG=en_US.UTF-8previous=NPREVLEVEL=N

Now to get that output more readable, you can do two things. Either parse the null character (\0) and replace them by new lines (\n) or use the strings tool that does this for you.

Let’s take the hard path first, to see what’s going on.

$ cat /proc/28818/environ | tr '\0' '\n'
TERM=linux
PATH=/sbin:/usr/sbin:/bin:/usr/bin
runlevel=3
RUNLEVEL=3
SUPERVISOR_GROUP_NAME=xxx
PWD=/path/to/your/homedir
LANGSH_SOURCED=1
LANG=en_US.UTF-8
previous=N
PREVLEVEL=N

Alternatively, you can use strings directly on the file.

$ strings /proc/28818/environ
TERM=linux
PATH=/sbin:/usr/sbin:/bin:/usr/bin
runlevel=3
RUNLEVEL=3
SUPERVISOR_GROUP_NAME=xxx
PWD=/path/to/your/homedir
LANGSH_SOURCED=1
LANG=en_US.UTF-8
previous=N
PREVLEVEL=N

You could also add the e modifier to ps to also show all environment variables. Personally, I find /proc easier to interpret, since it only shows the environment variables.

$ ps e -ww -p 28818
PID TTY      STAT   TIME COMMAND
28818 ?   Sl   0:00 /path/to/your/script.sh TERM=linux PATH=/sbin:/usr/sbin:/bin:/usr/bin runlevel=3 RUNLEVEL=3 SUPERVISOR_GROUP_NAME=xxx PWD=/var/www/vhosts/worker.nucleus.be/cron-tasks LANGSH_SOURCED=1 LANG=en_US.UTF-8 previous=N

If you’ve got other tricks, I’d love to hear about them!



Want to subscribe to the cron.weekly newsletter?

I write a weekly-ish newsletter on Linux, open source & webdevelopment called cron.weekly.

It features the latest news, guides & tutorials and new open source projects. You can sign up via email below.

No spam. Just some good, practical Linux & open source content.