Programming Perl, 4th Edition

ucfirst

ucfirst EXPR
ucfirst

This function returns a version of EXPR with the first character titlecased and other characters left alone. Titlecase is “Unicodese” for an initial capital that has (or expects to have) lowercase characters following it, not uppercase ones. Examples are the first letter of a sentence, of a person’s name, of a newspaper headline, or of most words in a title. Characters with no titlecase mapping return the uppercase mapping instead. This is the internal function implementing the \u escape in double-quoted strings.

For example, if someone used U+FB02 latin small ligature fl at the start of “flower” (that is, "\x{FB02}ower"), and you want to use it as the first word of a sentence, its titlecase mapping is “Flower”, not “FLower”. Its uppercase is still “FLOWER”, though.

To capitalize a string by mapping its first character to titlecase and the rest to lowercase, use:

ucfirst(substr($word, 0, 1)) . lc(substr($word, 1))

Do not (unless you’re into cultural imperialism) use:

ucfirst lc $word

or "\u\L$word", because that can produce a different and incorrect answer with certain characters. The titlecase of something that’s been lowercased doesn’t always produce the same thing titlecasing the original produces.

Because titlecasing only makes sense at the start of a string ...