_TOLOWER(3POSIX) - man page online | library functions
Transliterate uppercase characters to lowercase.
_TOLOWER(3POSIX) POSIX Programmer's Manual _TOLOWER(3POSIX)
PROLOGThis 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);
DESCRIPTIONThe _tolower() macro shall be equivalent to tolower(c) except that the application shall ensure that the argument c is an uppercase letter.
RETURN VALUEUpon successful completion, _tolower() shall return the lowercase letter corresponding to the argument passed.
ERRORSNo errors are defined. The following sections are informative.
APPLICATION USAGEApplications should use the tolower() function instead of the obsolescent _tolower() func‐ tion.
FUTURE DIRECTIONSThe _tolower() function may be removed in a future version.
SEE ALSOtolower(), isupper() The Base Definitions volume of POSIX.1‐2008, Chapter 7, Locale, <ctype.h>
IEEE/The Open Group 2013 _TOLOWER(3POSIX)
COPYRIGHTPortions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 7, Copyright (C) 2013 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the event of any discrep‐ ancy 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.unix.org/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 .