Man page - fctolower(3)
Packages contains this manual
Manual
FcToLower
NAMESYNOPSIS
DESCRIPTION
NAME
FcToLower - convert upper case ASCII to lower case
SYNOPSIS
#include <fontconfig/fontconfig.h>
FcChar8 FcToLower (FcChar8 c );
DESCRIPTION
This macro converts upper case ASCII c to the equivalent lower case letter.