Question

This is the continuation of my previous question.
deleting lines from text files based on the last character which are in another file using awk or sed

I am trying to get the following output using my previous example? I am new to awk.Please give suggestions.

 csh    1      A   1      27.704   6.347   
 csh    2      A   1      28.832   5.553
 csh    3      A   1      28.324   4.589
 csh    6      A   1      28.378   4.899

Answer 1

Taking some code from previous answers, you can use this code:

while read word; do
    if [[ $word =~ ^(....)(.)$ ]]; then
        filename="yy/${BASH_REMATCH[1]}.txt"
        letter=${BASH_REMATCH[2]}
        [[ -f $filename ]] && sed -i.bak -n "/^ *csh.*$letter/p" $filename
    fi
done < xx.txt