|| POSIX Programmer's Manual
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
tolower() function has as a domain a type
int, the value of which is representable as an
unsigned char or the value of EOF. If the argument has any other value, the behavior is undefined. If the argument of
tolower() represents an uppercase letter, and there exists a corresponding lowercase letter (as defined by character type information in the program locale category
LC_CTYPE ), the result shall be the corresponding lowercase letter. All other arguments in the domain are returned unchanged.
RETURN VALUE Upon successful completion,
tolower() shall return the lowercase letter corresponding to the argument passed; otherwise, it shall return the argument unchanged.
No errors are defined.
The following sections are informative.
APPLICATION USAGE None.
FUTURE DIRECTIONS None.
setlocale(), the Base Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale,
COPYRIGHT Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 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 .