.TH TOLOWER 3 .CT 2 data_man .SH NAME tolower, toupper \(mi force upper or lower case .SH SYNOPSIS .B tolower(character) .PP .B toupper(character) .SH DESCRIPTION If .I character is an upper case letter, .I tolower returns the same lower case letter, otherwise it returns the original character. .PP .I Toupper does the reverse. .SH SEE ALSO .IR ctype (3)