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set command displays all the local variables like below. How do I export these variables all at once?

>set
a=123
b="asd asd"
c="hello world"
Kusalananda
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Neerav
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  • what do you mean export all at once? you can use semi colons to define in one line...like a=123;b="asd asd";c="hello world" – Raza Jun 11 '13 at 20:57
  • Very similar to http://unix.stackexchange.com/q/79064/4667 – glenn jackman Jun 11 '13 at 21:00
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    `set` also displays functions and system variables like BASH_VERSION – glenn jackman Jun 11 '13 at 21:02
  • Your question is unclear. Is that an excerpt of `set` output you're showing? If so, then it's not `bash`'s. Do you want to export all the currently set variable including the special shell variables? Or only those 3 variables like in `export a b c`? – Stéphane Chazelas Jun 11 '13 at 21:07
  • `export ${!T*}` would export any defined parameter whose name starts with `T`. Unfortunately, there doesn't seem to be a way to easily generate a list of *all* defined parameters. – chepner Jun 13 '13 at 15:43

5 Answers5

140

Run the following command, before setting the variables:

set -a
set -o allexport  # self-documenting version

man page:

-a
When this option is on, the export attribute shall be set for each variable to which an assignment is performed

-o option-name
Set the option corresponding to option-name:

  • allexport
    Same as -a.

To turn this option off, run set +a or set +o allexport afterwards.

Example:

set -a  # or: set -o allexport 
. ./environment
set +a

Where environment contains:

FOO=BAR
BAS='quote when using spaces, (, >, $, ; etc'
Stéphane Chazelas
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Nitin4873
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8

Same preliminary requirement as chosen answer ... either explicitly export each variable as per

export aaaa=1234

or prior to any variable assignment issue

set -a  #  for details see answer by @nitin

then this works if your shell is bash ( possibly other shells as well )

export > /my/env/var/file

your new file will contain a dump of all currently defined variables ... with entries like

declare -x PORT="9000"
declare -x PORT_ADMIN="3001"
declare -x PORT_DOCKER_REGISTRY="5000"
declare -x PORT_ENDUSER="3000"
declare -x PRE_BUILD_DIR="/cryptdata6/var/log/tmp/khufu01/loud_deploy/curr/loud-build/hygge"
declare -x PROJECT_ID="hygge"
declare -x PROJECT_ID_BUSHIDO="bushido"

then to jack up current shell with all those env vars issue

source  /my/env/var/file
Scott Stensland
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    I believe `export` only prints variables that are already (marked to be) exported, while I believe the question is about variables that are set, but not marked to be exported. I just tested this on bash, which prints nothing: `FOOBAR=x; export | grep FOOBAR`. – Matthijs Kooijman Mar 09 '22 at 15:58
  • @MatthijsKooijman good catch I updated to qualify my answer – Scott Stensland Mar 10 '22 at 12:07
5
`echo "export" $((set -o posix ; set)|awk -F "=" 'BEGIN{ORS=" "}1 $1~/[a-zA-Z_][a-zA-Z0-9_]*/ {print $1}')`

  1. First, get all set environment variables: (set -o posix ; set) Reference: https://superuser.com/questions/420295/how-do-i-see-a-list-of-all-currently-defined-environment-variables-in-a-linux-ba

  2. Get all environment variable names, separated by space: awk -F "=" 'BEGIN{ORS=" "}1 $1~/[a-zA-Z_][a-zA-Z0-9_]*/ {print $1}' Reference: awk-Printing column value without new line and adding comma and https://stackoverflow.com/questions/14212993/regular-expression-to-match-a-pattern-inside-awk-command

  3. Now, we need to export these variables, but xargs can not do this because it forks child process, export have to be run under current process. echo "export" ... build a command we want, then use `` to run it. That's all :p.

Wil Moore III
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Bear Huang
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  • Welcomme to U&L SE. Maybe you can edit your post and give some explication. – Archemar Mar 06 '15 at 12:09
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    It's not correct to assume environment variable names will consist solely of a-z and A-Z. They commonly include underscores and digits as well, so the pattern would be `[a-zA-Z_][a-zA-Z0-9_]*`. There are some variations on this based on the shell you're using, but this is the safe / portable approach. – Chris Johnson May 05 '17 at 17:27
  • Good point @ChrisJohnson - updated! – Wil Moore III Aug 29 '17 at 15:52
3

compgen -v will print a list of all variable names so you can export them all with

export $(compgen -v)

This will have various effects depending on the variables you have defined (ex: BASHOPTS will get exported by this). Be wary of how you use this.

johncs
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  • Or just `export $(compgen -v)` (also assuming an unmodified `$IFS`), bearing in mind that exporting bash builtin variables such as `SHELLOPTS` or `BASHOPTS` can have nasty consequences. – Stéphane Chazelas Feb 06 '22 at 15:01
  • Thanks, I never realized `export` accepts multiple symbols. I've incorporated most of your comment into the answer. – johncs Feb 12 '22 at 00:54
2

You can prepend export to the variable name via awk and eval the resulting output:

eval $(printenv | awk -F= '{ print "export " $1 }')
muru
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Wil Moore III
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    `printenv` prints the variables that are already exported. That also won't work properly if there are variables that contain newline characters. – Stéphane Chazelas Aug 29 '17 at 10:57