find complete text in a one file and replace the string in another file

Question

I have data like this in Source_file.txt

5daee1ef55297ba2fac78933

And in Target_file.txt has

$$API_JOB_ID=5daed2a255297ba2fac78930
$$API_JOB_RES=succeeded
$$API_SERVER=awsabc1108

Now, I need to replace the Source_file.txt value in Target_file.txt.

Output should be like below

$$API_JOB_ID=5daee1ef55297ba2fac78933
$$API_JOB_RES=succeeded
$$API_SERVER=awsabc1108

Please note that Source_file.txt values are dynamically changing every time when other processes completed. Hence Target file has to be updated every time with correct $$API_JOB_ID

I would need the Unix command to resolve this.

Answer 1

Ok, this is kind of dirty, but it should work:

sed 's/\$\$API_JOB_ID=.*$/\$\$API_JOB_ID='"$(cat Source_file.txt)"'/' Target_file.txt

If you want to directly edit your target file instead of printing the modified version to your terminal, use this instead:

sed -i 's/\$\$API_JOB_ID=.*$/\$\$API_JOB_ID='"$(cat Source_file.txt)"'/' Target_file.txt

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It's dirty, mainly, because I'm making TOO MANY assumptions about the format of your files, and the command success, heavily depends on those assumptions; if we want to do this right, we need to know exactly what assumptions we can make, but your description was kinda vague. If you think that this can fail cause you can have other formats or more complex structure in your Source_file.txt and Target_file.txt files, we need to know about that.