Convert character string to lowercase characters. This does not affect non-alpha characters outside the 26 alphabets.
Convert the values in column to lowercase characters.
$ more dat1.csv id,str 1,ABC 2,aB$12!Cd 3, 4,cBA $ mcal c='tolower($s{str})' a=rsl i=dat1.csv o=rsl1.csv #END# kgcal a=rsl c=tolower($s{str}) i=dat1.csv o=rsl1.csv $ more rsl1.csv id,str,rsl 1,ABC,abc 2,aB$12!Cd,ab$12!cd 3,, 4,cBA,cba