Skip to content

Instantly share code, notes, and snippets.

Created March 22, 2017 13:34
Show Gist options
  • Save judy2k/7656bfe3b322d669ef75364a46327836 to your computer and use it in GitHub Desktop.
Save judy2k/7656bfe3b322d669ef75364a46327836 to your computer and use it in GitHub Desktop.
Parse a .env (dotenv) file directly using BASH
# Pass the env-vars to MYCOMMAND
eval $(egrep -v '^#' .env | xargs) MYCOMMAND
# … or ...
# Export the vars in .env into your shell:
export $(egrep -v '^#' .env | xargs)
Copy link

LuanP commented Mar 18, 2021

Considering only the first =:

eval "$(grep -v '^#' .env | sed -E '0,/^(.+)=/s/^(.+)=(.*)$/export \1=${\1:-\2}/g' | xargs -L 1)"

Copy link

j0eii commented Mar 23, 2021

  echo $(grep -v '^#' .env | grep -e "$1" | sed -e 's/.*=//')

CUR_APP_ENV=$(read_var "APP_ENV")

Not to override APP_ENV caz it will breaks .env hot reload.

Copy link

Used export $(grep -v '^#' .env | xargs -d '\r\n') to trim \r from lines.

Copy link

ko1nksm commented Apr 12, 2021

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.

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.

Copy link

smac89 commented Apr 15, 2021

The following worked well for me in github actions:

eval "cat <<EOF
$(egrep -v '^#' .env)
" | tee --append $GITHUB_ENV

Tips for using this (things that bit me):

  • Don't quote anything unless absolutely necessary; the quotes will be taken literally
  • Avoid interpolation which uses a variable inside the .env file. So if your file contains FOO and you try to use in in another variable like FOOBAR=${FOO}bar, all you will get is FOOBAR=bar

Apart from these, it supports pretty much anything you can do regularly including using variables that store the output of a command

Copy link

adriancuadrado commented Apr 15, 2021

Here is my contribution, which I developed with no idea someone already did something similar (I saw too many comments and I decided to develop it instead of reading all of them):

eval "$(
    cat <(
        grep -vE -e '^\s*#' -e '^\s*$' < .env |
        grep -E "^[A-Z0-9_]+=['\"]"
    ) <(
        grep -vE -e '^\s*#' -e '^\s*$' -e "^[A-Z0-9_]+=['\"]" < .env |
        sed -r "s/^([A-Z0-9_]+=)(.*)/\\1'\\2'/"


  1. Remove all comments and empty lines:
    • Regex for comments: ^\s*#
    • Regex for empty lines: ^\s*$
    • Grep command:
      grep -vE -e '^\s*#' -e '^\s*$' < .env
  2. Get all variables that do not need treatment (i.e. those which are already inside quotes):
    grep -E "^[A-Z0-9_]+=['\"]"
  3. Pipe step 1 to step 2:
    grep -vE -e '^\s*#' -e '^\s*$' < .env |
    grep -E "^[A-Z0-9_]+=['\"]"
  4. Use process substitution to pass the result as a parameter to cat (I could have used a temporal file, but meh):
        grep -vE -e '^\s*#' -e '^\s*$' < .env |
        grep -E "^[A-Z0-9_]+=['\"]"
  5. Get all variables that do need treatment:
    grep -vE -e '^\s*#' -e '^\s*$' -e "^[A-Z0-9_]+=['\"]" < .env

    Notice how the 3 regular expressions are the same as in steps 1 and 2. The only difference here is that I reuse the -v option with the third regex.

  6. Put the single quotes to avoid problems with special characters:
    • Regex for the variable with '=': ^([A-Z0-9_]+=)
    • Regex for the rest of the contents that must be inside single quotes: (.*)
    • Put the first group as is and the second between quotes: \\1'\\2'
    • Sed command:
      sed -r "s/^([A-Z0-9_]+=)(.*)/\\1'\\2'/"
  7. Pipe step 5 to step 6:
    grep -vE -e '^\s*#' -e '^\s*$' -e "^[A-Z0-9_]+=['\"]" < .env |
    sed -r "s/^([A-Z0-9_]+=)(.*)/\\1'\\2'/"
  8. Do pretty much the same as step 4:
        grep -vE -e '^\s*#' -e '^\s*$' -e "^[A-Z0-9_]+=['\"]" < .env |
        sed -r "s/^([A-Z0-9_]+=)(.*)/\\1'\\2'/"
  9. Concat and eval:
eval "$(
    cat <(
        grep -vE -e '^\s*#' -e '^\s*$' < .env |
        grep -E "^[A-Z0-9_]+=['\"]"
    ) <(
        grep -vE -e '^\s*#' -e '^\s*$' -e "^[A-Z0-9_]+=['\"]" < .env |
        sed -r "s/^([A-Z0-9_]+=)(.*)/\\1'\\2'/"

This is basically what @kolypto does here, but more complex and worse because it doesn't take into consideration the variables that contain single or double quotes inside them, because I should have been able to reuse the result of some grep commands and because maybe there is also a way to not have to feed 2 commands with the contents of the same file (I wrote < .env twice). I had some fun coding this at least ;)

Copy link

adriancuadrado commented Apr 15, 2021

If you are seeking for an aswer and have scrolled to the bottom to find it, here it is (thanks to @abij. You can see his answer here):

set -o allexport
eval $(cat '.env' | sed -e '/^#/d;/^\s*$/d' -e 's/\(\w*\)[ \t]*=[ \t]*\(.*\)/\1=\2/' -e "s/=['\"]\(.*\)['\"]/=\1/g" -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
eval $(cat '.env.local' | sed -e '/^#/d;/^\s*$/d' -e 's/\(\w*\)[ \t]*=[ \t]*\(.*\)/\1=\2/' -e "s/=['\"]\(.*\)['\"]/=\1/g" -e "s/'/'\\\''/g" -e "s/=\(.*\)/='\1'/g")
set +o allexport

Just make sure you execute that monster in the same folder that you have your .env file.
The second eval is to read the .env.local file, whose variables should override the ones in .env

Copy link

mopcweb commented Apr 19, 2021


local result=$(grep ^VAR_NAME=.* path/to/.env | cut -d "=" -f 2);

More protected function to get necessary var and throw error if VAR not found, or invalid path provided.


local port=`getEnvVar --var PORT --path ./some-project/.env`;
echo "port = $port";


# Throws error - if it is.
# @example: exitIfError $? "Your error text".
# @example: exitIfError $1 "Your error text".
function exitIfError() {
  local exit_code=$1
  [[ $exit_code ]] &&
    ((exit_code != 0)) && {
      echo "ERROR. $@" >&2;
      exit "$exit_code";

# Gets ENV property from provided .env file
# @param var - Variable name
# @param path - Path to env file.
# @param [file] - Optional fileName param. @default .env.
function getEnvVar() {
  # This line is necessary to parse function named args
  # @see
  while [[ $# -gt 0 ]]; do if [[ $1 == *"--"* ]]; then if [[ $2 != *"--"* ]]; then local "${1/--/}"="${2:-true}"; else local "${1/--/}"=true; fi; fi; shift; done;
  [[ -n $file ]] && local fileName=$file || local fileName=".env";

  [[ -z $var || -z $path ]] && exitIfError 1 "getEnvVar: --var & --path are required.";
  [[ ! -d $path ]] && exitIfError 1 "getEnvVar: --path should be a valid dir.";

  local result=$(grep ^$var=.* $path/$fileName | cut -d "=" -f 2);

  [[ -z $result ]] && exitIfError 1 "getEnvVar: there is no such $var var in $path/$fileName file.";

  echo $result;

Copy link

abij commented Apr 19, 2021

@mopcweb Can you update with input and output, what is supported in the .env file?
And how much fun did you have, creating your own solution ;)?

# INPUT                     Expected:
'FOO=value'                 FOO='value'
"FOO=#value # comment"      FOO='#value # comment'
"FOO=value   "              FOO='value   '
'FOO='                      FOO=''
'export FOO=value'          export FOO='value'
"FOO=foo bar"               FOO='foo bar'
"FOO=   foo"                FOO='   foo'

Test cases from @ko1nksm:
Note: check his awesome script: !

Copy link

lzkill commented May 5, 2021

Why not dotenv-cli?

$ dotenv <command with arguments> 
# or
$ dotenv -e .env.custom <command with arguments>

Copy link

loopmode commented May 5, 2021

Because not every system has nodejs on it. And it's good that way.

Copy link

geoffjukes commented May 11, 2021

One-liner that allows unquoted variables that contain spaces:

OLD_IFS=$IFS; IFS=$'\n'; for x in `grep -v '^#.*' .env`; do export $x; done; IFS=$OLD_IFS

Copy link

ead_var() {
VAR=$(grep $1 $2 | xargs)
IFS="=" read -ra VAR <<< "$VAR"
echo ${VAR[1]}

MY_VAR=$(read_var MY_VAR .env)

Perfect, thanks

Copy link

What about this

# save the existing environment variables

# if the .env file exists, source it
[ -f .env ] && . .env

# re-export all vars from the env so they override what ever was set in .env
for e in $prevEnv
    export $e

Copy link

wieczorek1990 commented Jan 21, 2022

I wrote my own because was using forbidden symbols in envs.

This basically adds apostrophes so that all variables will be treated as strings. This way you can use your Docker env files and source them with source

import sys

def main(input_path, postfix='.sh'):
    with open(input_path, 'r') as file_handle:
        lines = file_handle.readlines()
        envs = {}
        for line in lines:
                parts = line.split('=')
                name = parts[0]
                value = ''.join(parts[1:]).rstrip('\n')
            except ValueError:
                envs[name] = value

    output_path = f'{input_path}{postfix}'
    with open(output_path, 'w') as file_handle:
        lines = []
        for name, value in envs.items():
            line = f'{name}=\'{value}\'\n'

if __name__ == '__main__':
    # Passes first argument as input path.

Copy link

andylamp commented Mar 12, 2023

The solution proposed by @arizonaherbaltea will not work correctly when the file is not terminated with a newline. For example using this .env example,

# test.env

Will not work properly, whereas the following will,

# test.env

The only change is adding a newline at the end of the file. This is because read requires a newline to parse the line correctly. Thus, in order to ensure everything works properly we can add a check to see if the file ends with newline and if not append it before parsing it. Doing this will ensure all lines are parsed correctly.


function export_envs() {
  local env_file=${1:-.env}
  local is_comment='^[[:space:]]*#'
  local is_blank='^[[:space:]]*$'
  echo "trying env file: ${env_file}"

  # ensure it has a newline that the end, if it does not already
  tail_line=`tail -n 1 "${env_file}"`
  if [[ "${tail_line}" != "" ]]; then
      echo "No Newline at end of ${env_file}, appending!"
      echo "" >> "${env_file}"

  while IFS= read -r line; do
    echo "${line}"
    [[ $line =~ $is_comment ]] && continue
    [[ $line =~ $is_blank ]] && continue
    key=$(echo "$line" | cut -d '=' -f 1)
    # shellcheck disable=SC2034
    value=$(echo "$line" | cut -d '=' -f 2-)
    # shellcheck disable=SC2116,SC1083
    echo "The key: ${key} and value: ${value}"
    eval "export ${key}=\"$(echo \${value})\""
  done < <(cat "${env_file}")

export_envs ${1}

Then it results,

✗ ./ test.env
trying env file: test.env
The key: MY_VAR and value: a
The key: MY_VAR and value: b

Hope this helps someone out there :)

Copy link

I've been using shdotenv from @ko1nksm and it's been great.

You can do shdotenv my-command to parse and run a command.
If you want to export the variables to the shell session, use eval $(shdotenv).

Copy link

tgrushka commented Feb 6, 2024

What's wrong with:

if [ -f .env ]; then
    set -o allexport
    source .env

Works on macOS with my .env that works with docker compose and does not have quotes around every string.

Test with:

envsubst < "$secret_file" | cat

later in the same script.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment