center                   center string
copies                   copy string
deletec                  delete characters
gsub                     global substitution
index                    index of string
insert                   insert string
justify                  justify line
length                   input length
match                    match regular expression
overlay                  overlay s2 on s1
remove                   remove characters
replace                  replace sub-expressions
sdate                    system date
split                    split string
srange                   range string
srev                     reverse string
stime                    system time
stran                    translate characters
strim                    trim characters
strlwr                   lower case
strupr                   upper case
sub                      substitute
substr                   sub-string