Answer by unxnut for Link variables between two text files

I am surprised nobody has suggested using arrays. Here is my crude attempt (using the log3.txt idea from @Stephane above.

#!/bin/bashnl1=$( wc -l < log1.txt )nl2=$( wc -l < log2.txt )nlnums=$( wc -l < nums.txt )declare -a arr1[$nl1]declare -a arr2[$nl2]declare -a nums[$nlnums]for (( i=0; i < $nl1; i++ ))do    read arr1[$i]done < log1.txtfor (( i=0; i < $nl2; i++ ))do    read arr2[$i]done < log2.txtfor (( i=0; i < $nlnums; i++ ))do    read nums[$i]done < nums.txtj=0for (( i=0; i < $nl1; i++ ))do    echo "The ${nums[$i]} color ${arr1[$i]} is ${arr2[$j]}"    j=$(( (j+1) % $nl2 ))done

The file nums.txt is as follows:

firstsecondthirdfourthfifthsixthseventheighthninthtenth

The code needs to be cleaned a bit but illustrates the point.