$ awk -v OFS='t' 'NR==1 { print $0, "Remark1", "Remark2"; next }NR==FNR { a[$1]=$0; next }$1 in a { print a[$1], $2, $3 }' Test1.txt Test2.txtID Name Telephone Remark1 Remark21 John 011 Test1 Test22 Sam 013 Test3 Test43 Jena 014 Test5 Test64 Peter 015 Test7 Test8
