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how to expand environment variables in a file?


 
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# 1  
how to expand environment variables in a file?

I am new to unix and would appreciate if someone could help.

I have an environment variable SourceFilePath=/db1/Src/test set on the unix server.

I want to expand this SHELL variable in a file using any command sed, awk etc

File contents is as follows:

var=$SourceFilePath/file.txt

The command should create a new file by subsituting the environment variable with the actual value.

The output should look like this.

var=/db1/Src/test/file.txt
# 2  
I think you mean to 'get the value of' a variable or maybe dereference it.

Do you mean you want to create a file using a variable as a filename?
Code:
SourceFilePath=/db1/Src/test 
var=${SourceFilePath}/file.txt
> $var     # this creates an empty file named /db1/Src/test/file.txt

# 3  
Hi Jim,
I want to substitute the value for ${SourceFilePath} and not create a file with the variable name. file.txt is already existing.

My scenario is like this.

file.txt is present on the TEST & DEV
I want to use the environment variable to point either to TEST or DEV.
So i will have one parameter file
PATH=$SourceFilePath/file.txt

I want to write a script which will generate a new file for the following system
TEST server should create a new file abc.txt with the following content

PATH=/db1/Src/test/file.txt

DEV server should create a new file xyx.txt with the following content

PATH=/db1/Src/dev/file.txt

The command or script must only substitute the value for the environment variable.

Thanks for your input.
 

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