Can I Export A Variable To The Environment From A Bash Script Without Sourcing It?
Answer :
Is there any way to access to the
$VAR
by just executingexport.bash
without sourcing it ?
Quick answer: No.
But there are several possible workarounds.
The most obvious one, which you've already mentioned, is to use source
or .
to execute the script in the context of the calling shell:
$ cat set-vars1.sh export FOO=BAR $ . set-vars1.sh $ echo $FOO BAR
Another way is to have the script, rather than setting an environment variable, print commands that will set the environment variable:
$ cat set-vars2.sh #!/bin/bash echo export FOO=BAR $ eval "$(./set-vars2.sh)" $ echo "$FOO" BAR
A third approach is to have a script that sets your environment variable(s) internally and then invokes a specified command with that environment:
$ cat set-vars3.sh #!/bin/bash export FOO=BAR exec "$@" $ ./set-vars3.sh printenv | grep FOO FOO=BAR
This last approach can be quite useful, though it's inconvenient for interactive use since it doesn't give you the settings in your current shell (with all the other settings and history you've built up).
In order to export out the VAR variable first the most logical and seems working way is to source the variable:
. ./export.bash
or
source ./export.bash
Now when echoing from main shell it works
echo $VAR HELLO, VARABLE
We will now reset VAR
export VAR="" echo $VAR
Now we will execute a script to source the variable then unset it :
./test-export.sh HELLO, VARABLE -- .
the code: cat test-export.sh
#!/bin/bash # Source env variable source ./export.bash # echo out the variable in test script echo $VAR # unset the variable unset VAR # echo a few dotted lines echo "---" # now return VAR which is blank echo $VAR
Here is one way
PLEASE NOTE: The exports are limited to the script that execute the exports in your main console - so as far as a cron job I would add it like the console like below... for the command part still questionable: here is how you would run in from your shell:
On your command prompt (so long as the export.bash has multiple echo values)
IFS=$'\n'; for entries in $(./export.bash); do export $entries; done; ./v1.sh HELLO THERE HI THERE
cat v1.sh
#!/bin/bash echo $VAR echo $VAR1
Now so long as this is for your usage - you could make the variables available for your scripts at any time by doing a bash alias like this:
myvars ./v1.sh HELLO THERE HI THERE echo $VAR .
add this to your .bashrc
function myvars() { IFS=$'\n'; for entries in $(./export.bash); do export $entries; done; "$@"; for entries in $(./export.bash); do variable=$(echo $entries|awk -F"=" '{print $1}'); unset $variable; done }
source your bashrc file and you can do like above any time ...
Anyhow back to the rest of it..
This has made it available globally then executed the script..
simply echo it out then run export on the echo !
cat export.bash
#!/bin/bash echo "VAR=HELLO THERE"
Now within script or your console run:
export "$(./export.bash)"
Try:
echo $VAR HELLO THERE
Multiple values so long as you know what you are expecting in another script using above method:
cat export.bash
#!/bin/bash echo "VAR=HELLO THERE" echo "VAR1=HI THERE"
cat test-export.sh
#!/bin/bash IFS=$'\n' for entries in $(./export.bash); do export $entries done echo "round 1" echo $VAR echo $VAR1 for entries in $(./export.bash); do variable=$(echo $entries|awk -F"=" '{print $1}'); unset $variable done echo "round 2" echo $VAR echo $VAR1
Now the results
./test-export.sh round 1 HELLO THERE HI THERE round 2 .
and the final final update to auto assign read the VARIABLES:
./test-export.sh Round 0 - Export out then find variable name - Set current variable to the variable exported then echo its value $VAR has value of HELLO THERE $VAR1 has value of HI THERE round 1 - we know what was exported and we will echo out known variables HELLO THERE HI THERE Round 2 - We will just return the variable names and unset them round 3 - Now we get nothing back
The script: cat test-export.sh
#!/bin/bash IFS=$'\n' echo "Round 0 - Export out then find variable name - " echo "Set current variable to the variable exported then echo its value" for entries in $(./export.bash); do variable=$(echo $entries|awk -F"=" '{print $1}'); export $entries eval current_variable=\$$variable echo "\$$variable has value of $current_variable" done echo "round 1 - we know what was exported and we will echo out known variables" echo $VAR echo $VAR1 echo "Round 2 - We will just return the variable names and unset them " for entries in $(./export.bash); do variable=$(echo $entries|awk -F"=" '{print $1}'); unset $variable done echo "round 3 - Now we get nothing back" echo $VAR echo $VAR1
Execute
set -o allexport
Any variables you source from a file after this will be exported in your shell.
source conf-file
When you're done execute. This will disable allexport mode.
set +o allexport
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