Load environment variables from dotenv / .env file in Bash

load_dotenv.sh

# The initial version
if [ ! -f .env ]
then
  export $(cat .env | xargs)
fi

# My favorite from the comments. Thanks @richarddewit & others!
set -a && source .env && set +a

The Problem

The problem with .env files is that they're like bash, but not completely.
While in bash you'd sometimes put quotes around values:

name='value ! with > special & characters'

in .env files there are no special characters, and quotes are not supported: they're part of the value. As a result, such a string has to be escaped when imported into bash.

The Solution

This version withstands every special character in values:

set -a
source <(cat development.env | sed -e '/^#/d;/^\s*$/d' -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
set +a

Explanation:

• -a means that every bash variable would become an environment variable
• /^#/d removes comments (strings that start with #)
• /^\s*$/d removes empty strings, including whitespace
• "s/'/'\\\''/g" replaces every single quote with '\'', which is a trick sequence in bash to produce a quote :)
• "s/=\(.*\)/='\1'/g" converts every a=b into a='b'

As a result, you are able to use special characters :)

To debug this code, replace source with cat and you'll see what this command produces.

@kolypto this doesn't work on comments after the assignment:
c=3 # three is prime

or with assignments to previously defined variables:
q='this string'
s=$q

export $(echo $(cat .env | sed 's/#.*//g'| xargs) | envsubst)

This is the best one for me as I desperately needed POSIX variable substitution to work

@drjasonharrison the examples that you show are not a .env file; it's a bash file :)
If you want comments, and assigmnents, in the file that you're going to load, you don't need this thread at all ))) Just source it! bash can source bash )

The cleanest solution I found for this was using allexport and source like this

set -o allexport
source .env set
+o allexport

For anyone researching in search engines (as that's how I came across this), here's my take on it, combining @kolypto addition of substitution + fixes, original poster's use of confirming the .env file exists, several mentioning the use of set -a

# Confirm .env file exists
if [ -f .env ]; then

    # Create tmp clone
    cat .env > .env.tmp;

    # Subtitutions + fixes to .env.tmp2
    cat .env.tmp | sed -e '/^#/d;/^\s*$/d' -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g" > .env.tmp2

    # Set the vars
    set -a; source .env.tmp2; set +a

    # Remove tmp files
    rm .env.tmp .env.tmp2

fi

I'm favorable of cases with incorrect variable usage in .env
test=hi there

Using the above method will fix the issue automatically.

FWIW If you need to just run a command with environment from an env file, this could help:

env $(cat .env|xargs) CMD

provided there are no other lines except env definitions in form of VAR=VALUE. Don't remember where I found it, but does the trick for me.

FWIW If you need to just run a command with environment from an env file, this could help:

env $(cat .env|xargs) CMD

provided there are no other lines except env definitions in form of VAR=VALUE. Don't remember where I found it, but does the trick for me.

Well that could have saved me an hour or two. 😁 The main reason for my answer was to incorporate the fixes that @kolypto mentioned.

Thanks for the info.

I had some problems with carriage return (\r) with dotenv files created via VS Code, so i'd like to share the code i used that resolved it:

export $(echo $(cat .env | sed 's/#.*//g' | sed 's/\r//g' | xargs) | envsubst)

I had some problems with carriage return (\r) with dotenv files created via VS Code, so i'd like to share the code i used that resolved it:

export $(echo $(cat .env | sed 's/#.*//g' | sed 's/\r//g' | xargs) | envsubst)

Thank you, great addition!

Since .env is so widely used, I think it would be a great addition to native Linux. Any clue how we could submit this as an addition to different distros? I mean integrated into the OS itself. I'm familiar with Linux and its commands but not how to submit an idea. I suppose it would be something I could fork and submit a pull request for.

Seeing that this thread has been going on for long years, I figured we need a dotenv tool for the shell.

And I wrote it.
https://github.com/ko1nksm/shdotenv

There is no formal specification for .env, and each is slightly different, but shdotenv supports them and correctly parses comments, whitespace, quotes, etc. It is a single file shell script that requires only awk and runs lightly.

There is no need to waste time on trial and error anymore.

Seeing that this thread has been going on for long years, I figured we need a dotenv tool for the shell.

And I wrote it.
https://github.com/ko1nksm/shdotenv

There is no formal specification for .env, and each is slightly different, but shdotenv supports them and correctly parses comments, whitespace, quotes, etc. It is a single file shell script that requires only awk and runs lightly.

There is no need to waste time on trial and error anymore.

This is great!

Wow @ko1nksm! This looks incredibly thorough. I look forward to using it, thank you.

FWIW - I found this helpful, but it didn't do what I had expected. Modified it slightly to result in the following.

if [ -f .env ]
then
  export $(cat .env | sed 's/#.*//g' | xargs)
fi

👍 * 100

Thank you so much for your solution .

source .env

works for me

source .env

works for me

wont work if you have # in your .env

@abhidp sorry, i didn't check that case...

# Local .env
if [ -f .env ]; then
    # Load Environment Variables
    export $(cat .env | grep -v '#' | sed 's/\r$//' | awk '/=/ {print $1}' )
fi

is what I use.. <.< it allows me to comment inside of the .env file :X and handles /r proper.. hope that helps everyone <3

Here is a modified version of this code that allows for variable expansion

if [ -f .env ]; then
  export $(echo $(cat .env | sed 's/#.*//g'| xargs) | envsubst)
fi

This worked for me. Thanks

Went for:

loadEnv() {
  local envFile="${1?Missing environment file}"
  local environmentAsArray variableDeclaration
  mapfile environmentAsArray < <(
    grep --invert-match '^#' "${envFile}" \
      | grep --invert-match '^\s*$'
  ) # Uses grep to remove commented and blank lines
  for variableDeclaration in "${environmentAsArray[@]}"; do
    export "${variableDeclaration//[$'\r\n']}" # The substitution removes the line breaks
  done
}

It does not glob or swallow quotes, tested with:

WITH_QUOTES=''

# Comment
WITNESS=whatever

WITH_GLOB=*.sh

In this folder (so the glob matches the shell file):

.
├── .env
└── loadEnvTest.sh

With command:

source ./loadEnvTest.sh; loadEnv .env; echo "$WITH_QUOTES $WITH_GLOB"

Outputs:

'' *.sh

darbe habercisi

One I use (bash specific) which behaves correctly in presence of calling environment override:

. <(sed -n 's/^\([^#][^=]*\)=\(.*\)$/\1=${\1:-\2}/p' .env 2>/dev/null) || true

if [ ! -f .env ]
then
  export $(cat .env | xargs)
fi

I hate bash so much...... it took me 30 minutes to understand it should be if [ -f .env ] instead of if [ ! -f .env ] 😢

[ ! -f .env ] || export $(sed 's/#.*//g' .env | xargs)

Update:
TEXT="abc#def" not work as expected, so just replace line begin with #.

[ ! -f .env ] || export $(grep -v '^#' .env | xargs)

@chengxuncc

using export $(grep -v '^#' .env | xargs) could not export the following,

A=10
B=$A
C=${A}

now, echo $B produces $A while it should print 10

@chengxuncc

using export $(grep -v '^#' .env | xargs) could not export the following,

A=10
B=$A
C=${A}

now, echo $B produces $A while it should print 10

@ShivKJ Of course, it will equal to export A=10 B=$A C=${A} and doesn't work like shell script. Another example is /etc/environment have same behavior and don't accept variable definition.

If you're wondering how to load a .env file with direnv: direnv already supports that :)

dotenv "testing.env"

Docs: https://direnv.net/man/direnv-stdlib.1.html

The Problem

The problem with .env files is that they're like bash, but not completely.
While in bash you'd sometimes put quotes around values:

name='value ! with > special & characters'

in .env files there are no special characters, and quotes are not supported: they're part of the value. As a result, such a string has to be escaped when imported into bash.

The Solution

This version withstands every special character in values:

set -a
source <(cat development.env | sed -e '/^#/d;/^\s*$/d' -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
set +a

Explanation:

• -a means that every bash variable would become an environment variable
• /^#/d removes comments (strings that start with #)
• /^\s*$/d removes empty strings, including whitespace
• "s/'/'\\\''/g" replaces every single quote with '\'', which is a trick sequence in bash to produce a quote :)
• "s/=\(.*\)/='\1'/g" converts every a=b into a='b'

As a result, you are able to use special characters :)

To debug this code, replace source with cat and you'll see what this command produces.

Thank you! I have some long and unusually formatted environment variables, and this was the only solution which didn't choke on them.

~/bin/envs

set -a
source .env
set +a
exec $@

$> envs go run .