Shell Read string from one file and replace in other file

Question

My requirement is to read the string from input file and replace all its occurrences with replaced string into output file. Example:

$ cat input
BOB_XYZ  "JOB.ABC"
ROB_LOLA  "TOT.XYZ"
$ cat output
{
BOB_XYZ is a BOB_XYZ
I am BOB_XYZ
}

Here, I need to replace "BOB_XYZ" with "JOB.ABC" from output file. I mean expected output as

$ cat output
{
"JOB.ABC" is a "JOB.ABC"
I am "JOB.ABC"
} 

Please let me know, how we do this

Answer 1

Using awk, here is one way to do it. Loop through input and output files, collecting the "variables" from input into an array a and applying field-by-field replacements on output

awk 'NR == FNR{a[$1]=$2; next};
    {for (i=1; i<=NF; ++i) if ($i in a) $i=a[$i]; print}' input output