The awk extraction and reporting language provides the toupper and tolower functions for converting strings to uppercase or to lowercase:
tolower(STRING)
The tolower function returns a lowercase version of the STRING argument. This function converts all letters to lowercase in the returned string. Only the returned string is converted, the provided argument remains unchanged:
BEGIN { mystring = "I Like Apples" print (tolower(mystring)) print mystring }
toupper(STRING)
The toupper function returns a lowercase version of the STRING argument. This function converts all letters to uppercase in the returned string. Only the returned string is converted, the provided argument remains unchanged:
BEGIN { mystring = "I Like AppLes" print (toupper(mystring)) print mystring }
These function are affected by the following locale environment variable settings.