Question

I want to replace a lines that ends with ‘YES’ with ‘YES’ and replace lines that ends with ‘NO’with ‘NO’. I have to apply for a large file.

Input:

 max. C    13       0.457   0.32   YES
 max. Y    13       0.232   0.33   NO
 max. S     1       0.315   0.87   NO  

Output:

YES
NO
NO

Answer 1

perl -p -e 's/.*(YES|NO)\s*$/$1/;' 

If you want Y and N instead of YES and NO then change it to

s/.*(Y|N)[ESO]+$/$1/;

To read more about perl regular expressions, substitions, etc. check out “perldoc perlre” from the command line of your system where perl is installed