if [ ! -f .env ] | |
then | |
export $(cat .env | xargs) | |
fi |
I had troubles with a (Docker) setup where environment variables had spaces in their value without quotes and I needed to get the container's env. vars. in a script called during the container execution/runtime.
I ended getting the variables in the entrypoint, exporting them to a file and them reading them when needed.
# In entrypoint
export -pn \
| grep "=" \
| grep -v -e PATH -e PWD -e OLDPWD \
| cut -d ' ' -f 3- \
> /docker-container.env
The export
command fixes issues with missing quotes, avoiding errors where the shell interpreter tries to execute parts of the variable value as commands.
# In script
set -o allexport
. /docker-container.env
set +o allexport
(I had to use /bin/sh
so not using source file
but . file
)
Posix compliant version built around set
, [ ]
and .
Many thanks to the prior posters who brought up set -o a
and set -a
/ set +a
This snippet will source a dotenv file, exporting the values into the environment. If allexport
is already set, it leaves it set, otherwise it sets, reads, and unsets.
if [ -z "${-%%*a*}" ]; then
set -a
. ./.env
set +a
else
. ./.env
fi
double brackets [[
, source
, setopt
are not available in posix. Nor is the test [[ -o a ]]
to check for set options. And we need to quote our comparison strings to deal with empty vars.
The code to check if an option is set is a bit of a pain. It could be a case statement or a grep on set -o
like set -o | grep allexport | grep -q yes
, but blech. Instead I've used parameter expansion with pattern matching to remove a maximum match from the $-
variable containing a single line of the set options.
${-%%*a*}
uses %%
parameter expansion to remove the longest suffix matching the pattern *a*
. If $-
contains a
then this expansion produces and empty string which we can test with -z or -n.
subtle bug if no options are set, so the comparison "$-" = "${-%%a*}"
will check that the expansion changed the string. allexport
is set if the two strings differ. And even % will work as we don't need a maximal match and can remove the leading *
from our pattern match.
if [ "$-" = "${-%a*}" ]; then
# allexport is not set
set -a
. ./.env
set +a
else
. ./.env
fi
When the values have newline chars \n
, spaces or quotes, it can get messy.
After a lot of trial and error, I ended up with a variation of what @bergkvist proposed in https://gist.github.com/mihow/9c7f559807069a03e302605691f85572?permalink_comment_id=4245050#gistcomment-4245050 (thank you very much!).
ENV_VARS="$(cat .env | awk '!/^\s*#/' | awk '!/^\s*$/')"
eval "$(
printf '%s\n' "$ENV_VARS" | while IFS='' read -r line; do
key=$(printf '%s\n' "$line"| sed 's/"/\\"/g' | cut -d '=' -f 1)
value=$(printf '%s\n' "$line" | cut -d '=' -f 2- | sed 's/"/\\\"/g')
printf '%s\n' "export $key=\"$value\""
done
)"
env $(cat .env)
this does not work for me but this one works
env $(cat .env|xargs) CMD
my .env has some special value such as FOO='VPTO&wH7$^3ZHZX$o$udY4&i'
@NatoBoram
A simple solution that works for bash
, zsh
, and fish
:
eval export $(cat .env)
Use this to create the file
export -p > .env
and just
. .env
to read it back in
From man export
:
The shell shall format the output, including the proper use of quoting, so that it is suitable for reinput to the shell as commands that achieve the same exporting results
Although set -a; source .env; set +a
is elegant and short, one feature which I missed is this overwrite existing exported variables.
I my use case I have a script, which connects to postgres with a predefined user. This user is stored in .env
file as PG_USER=myuser
. So the script does the magical set -a; source .env; set +a
and everything works. But sometimes I need ad-hoc change the user. So what I'd do is PG_USER=postgres ./my_script.sh
. In order not to over write the existing var I did this horrendous piece of code:
IFS=$'\n'
for l in $(cat /etc/my_service/.env); do
IFS='=' read -ra VARVAL <<< "$l"
# If variable with such name already exists, preserves it's value
eval "export ${VARVAL[0]}=\${${VARVAL[0]}:-${VARVAL[1]}}"
done
unset IFS
The cleanest solution I found for this was using
allexport
andsource
like thisset -o allexport source .env set +o allexportThis was by far the best solution here for me, removed all the complexity around certain chars, spaces comments etc. Just needed a tweak on formatting to prevent others being tripped up, should be:
set -o allexport source .env set +o allexport
work like a charm. ty
this read line by line, allowing to use previous set variables
while read -r LINE; do if [[ $LINE == *'='* ]] && [[ $LINE != '#'* ]]; then ENV_VAR="$(echo $LINE | envsubst)" eval "declare $ENV_VAR" fi done < .env
this was working the best for me but this still has 2 problems
- code breaks if the value has
()
characters inside it - can not be used inside a function
here is my solution:
read_env() {
local filename="${1:-.env}"
if [ ! -f "$filename" ]; then
echo "missing ${filename} file"
exit 1
fi
echo "reading .env file..."
while read -r LINE; do
if [[ $LINE != '#'* ]] && [[ $LINE == *'='* ]]; then
export "$LINE"
fi
done < "$filename"
}
thank you this was better