Bash script with export variables

UNIX for Advanced & Expert Users
1

Hi all guys,

how you can read in thread title, I'm deploying a bash script in which I have to export some variables inside it.
But (I think you know) the export command works only inside the script and so, on exit command, the variables aren't set like I set inside the script.
Consequently in env file, variables are set like before the run of the script.

So, the question is easy: how can I set permanently the variables inside the script with export command?

Thx, bye.
Fabio

2

Source the script in the current shell:

. ./script_name

Note the dot `.` shell builtin at the beginning of the line.

3

Ok, but I need to do a similar thing inside the script.

4

So do it.

5

I'm sorry, but you intend for example, if my script is Test.sh e inside the code is:

#!/bin/bash
echo $1 > /tmp/output
bin_dir=$1
export bin_dir
exit 0

you mean I have to do:

#!/bin/bash
echo $1 > /tmp/output
bin_dir=$1
. ./Test.sh
export bin_dir
exit 0

right or not?

6

No.
if you have a script that sets and/or exports variables that are needed by another script,
you need to source the script that sets the environment inside the script that needs the new environment.

For example:

env_script.sh

export var1=value1 var2=value2 ...

main_script.sh

# source the env script
. /path/to/env_script.sh
# here the values of var1 and var2 are available

If you need to do something different, please be more specific.

7

see this post

8

Another approach if you just want to make the results of a called script available to the parent. Echo the results at the end of the called script and read the results in the parent script:

# abc01 - Top level script
var1="fred"
var2="joe"
var3="nothing"
var4="nothing"
./abc011 "${var1}" "${var2}" | read var3 var4
echo "var3=${var3}"
echo "var4=${var4}"


# abc011 - Script called from abc01
var5="${1}"
var6="${2}"
var7="${var5}-modified"
var8="${var6}-modified"
#
echo "${var7} ${var8}"


./abc01
var3=fred-modified
var4=joe-modified
9

idro, if I'm understanding the source of your confusion:

Environment variables are not global variables. You can't permanently set them for every other program, from one program. The closest thing there is to setting them globally is /etc/profile, and processes don't automatically get changes when you alter that -- it's read by shells on login and so forth.

How env vars work is child processes get copies from their parent on creation and thereafter are independent -- changes in the parent don't affect the child and vice versa.