NAME
foldup, folddown - perform case-folding on strings

SYNOPSIS
char *foldup (out,in);
char *out;
const char *in;

char *folddown (out,in);
char *out;
const char *in;

DESCRIPTION
Foldup and folddown perform case-folding (to upper or lower case,
respectively) on strings. The string at in is copied to the buffer
at out, changing letters as appropriate. Only letters are
affected.

It is specifically allowed for out and in to specify the same
string; in this manner, in-place case folding is possible. Both
folding routines return out as their value, for convenience.

BUGS
No "inversion" mode is provided. In-place case folding is
accomplished by specifying out and in as the same string; this is a
rather cumbersome way to specify the most common manner of case-
folding.