_TOLOWER(3POSIX)                            POSIX Programmer's Manual                           _TOLOWER(3POSIX)

PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of this interface
       may differ (consult the corresponding Linux manual page for details of Linux behavior), or the  interface
       may not be implemented on Linux.

NAME

       _tolower — transliterate uppercase characters to lowercase

SYNOPSIS

       #include <ctype.h>

       int _tolower(int c);

DESCRIPTION

       The  _tolower() macro shall be equivalent to tolower(c) except that the application shall ensure that the
       argument c is an uppercase letter.

RETURN VALUE

       Upon successful completion, _tolower() shall return the lowercase letter corresponding  to  the  argument
       passed.

ERRORS

       No errors are defined.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       Applications should use the tolower() function instead of the obsolescent _tolower() function.

RATIONALE

       None.

FUTURE DIRECTIONS

       The _tolower() function may be removed in a future version.

SEE ALSO

       tolower(), isupper()

       The Base Definitions volume of POSIX.1‐2017, Chapter 7, Locale, <ctype.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of Electrical  and  Electronics
       Engineers, Inc and The Open Group.  In the event of any discrepancy between this version and the original
       IEEE  and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document.
       The original Standard can be obtained online at http://www.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are most likely to have  been  introduced
       during   the   conversion  of  the  source  files  to  man  page  format.  To  report  such  errors,  see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .

IEEE/The Open Group                                   2017                                      _TOLOWER(3POSIX)