gnulib/doc/c-strcaseeq.texi

@c Documentation of gnulib module 'c-strcaseeq'.

@c Copyright (C) 2008--2025 Free Software Foundation, Inc.

@c Permission is granted to copy, distribute and/or modify this document
@c under the terms of the GNU Free Documentation License, Version 1.3 or
@c any later version published by the Free Software Foundation; with no
@c Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.  A
@c copy of the license is at <https://www.gnu.org/licenses/fdl-1.3.en.html>.

@mindex c-strcaseeq
The @code{c-strcaseeq} module contains an optimized case-insensitive
string comparison function operating on single-byte character strings, that
operate as if the locale encoding was ASCII.
(The "C" locale on many systems has the locale encoding "ASCII".)

The functions is actually implemented as a macro:
@smallexample
extern int STRCASEEQ (const char *s1, const char *s2,
                      int s20, int s21, int s22, int s23, int s24, int s25,
                      int s26, int s27, int s28);
@end smallexample

@var{s2} should be a short literal ASCII string, and @var{s20}, @var{s21}, ...
the individual characters of @var{s2}.

For case conversion here, only ASCII characters are considered to be
upper case or lower case.