SIMULATION - Find the rows that contain abcde from file /etc/testfile, and write it to the file/tmp/testfile, and the sequence is requested as the same as /etc/testfile.
Answer correct:
See explanation below.
# cat /etc/testfile | while read line; do echo $line | grep abcde | tee -a /tmp/testfile done OR - grep `abcde` /etc/testfile > /tmp/testfile