Shell Programming and Scripting

Hi Experts,

I have one scenario here. I want to extract the value of a variable as mentioned below using a shell script (bash).

I am having a file say File A. Inside the file, I have a variable assigned a string value.
File A:
Var1="value of the variable"

In a particular script "variable_name.sh", I am getting the input as Var1. Inside the script I am sourcing the File as well.
Executed as ./variable_name.sh Var1

I want to store the Var1's value inside another variable in the script as mentioned below.
Var_val=$1
extracted_variable=`echo "$[$Var_val]"`

Output required:
value of the variable

But when I try this, it is returned as 0. If I assign any number to Var1 (say Var1=100) then it is returning the value as 100.

Could you please help me in extracting the string value that is stored in Var1?

Regards & Thanks,
Vivek

Not sure if this is what you are after:-
Longhand using OSX 10.7.5, default bash terminal...

Code:

Last login: Tue Sep 15 09:01:15 on ttys000
AMIGA:barrywalker~> echo "VAR1='This is a test.'" > /tmp/variable
AMIGA:barrywalker~> source /tmp/variable
AMIGA:barrywalker~> VAR_VAL=$VAR1
AMIGA:barrywalker~> echo "$VAR_VAL"
This is a test.
AMIGA:barrywalker~> _

man bash: If you evaluate a text variable, it will evaluate to 0. Quote the variable when used as a parameter to a function as it contains spaces. You don't need the echo when assigning to a new variable.

Hi Wisecracker,

I am not assigning as such.
AMIGA:barrywalker~> VAR_VAL=$VAR1

I am assigning like VAR_key=$1 ($1 is the input to the script)
$1 will be VAR1

I want to retrieve the string that is present in VAR_key. That is what I am trying to do here,
extracted_variable=`echo "$[$Var_key]"`

<B>@RudiC </B> : Variable will not have a text with spaces. It will be a string like this.
"THIS_IS_A_TEXT".

Thanks.

The way to "retrieve" a variable in shell is $.

Code:

# VAR="value"
# echo $var

value

#

My requirement in simple words,

Var1="Value"
Var2=Var1

I want to assign "Value" to Var2. As per my original post, If I have a number instead of "value" then I am able to retrieve it.

Thanks

Do you mean like this:-
OSX 10.7.5, default terminal using 'sh'...

Code:

#!/bin/sh
# value
$1
echo $VAR1

Manually generate another file, (your File A), for testing and run 'value' file...

Code:

Last login: Tue Sep 15 19:47:17 on ttys000
AMIGA:barrywalker~> cd Desktop/Code/Shell
AMIGA:barrywalker~/Desktop/Code/Shell> chmod 755 value
AMIGA:barrywalker~/Desktop/Code/Shell> echo "VAR1=125" > /tmp/variable
AMIGA:barrywalker~/Desktop/Code/Shell> ./value 'source /tmp/variable'
125
AMIGA:barrywalker~/Desktop/Code/Shell> _

If this is NOT what you want the I have no idea what you have in mind...