Do you see any difference between:

Code:

> report.txt 
while read -r usr
do      finger "$usr" >> report.txt
done < sample.out

and:

Code:

while read -r `${usr}`
do
finger `${usr}`>> report.txt
done < sample.out

Reading into a variable name (usr) and reading into a variable named by the output of the command substitution of the expansion of a variable name (`${usr}`) are two COMPLETELY different things.

Passing the expansion of a variable name as an argument ("${usr}") and passing the output of the command substitution of the expansion of a variable name (`${usr}`) are two COMPLETELY different things.

Single quotes, back quotes, and double quotes all have meaning to the shell; and they all mean different things. Back quotes and double quotes ARE NOT INTERCHANGEABLE! Please try running the script I suggested (without changing it) and see if the results are different.

And, no, that is not what your script was doing. Your originally posted script executed the command:

Code:

finger > report.txt

once for each word in sample.out. (It sets the variable i to a different word in sample.out each time through the loop, but after setting the variable i, you never referenced it. It never set the variable usr, so the expansion of that variable ($usr) expanded to nothing.)