opensolaris man page for tolower

tolower(3C)						   Standard C Library Functions 					       tolower(3C)

NAME
       tolower - transliterate upper-case characters to lower-case

SYNOPSIS
       #include <ctype.h>

       int tolower(int c);

DESCRIPTION
       The  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 argument is returned unchanged. If the argument of tolower() represents an upper-case letter,	and  there
       exists  a  corresponding lower-case letter (as defined by character type information in the program locale category LC_CTYPE),	the result
       is the corresponding lower-case letter. All other arguments in the domain are returned unchanged.

RETURN VALUES
       On successful completion, tolower() returns the lower-case letter corresponding to the argument passed. Otherwise, it returns the  argument
       unchanged.

ERRORS
       No errors are defined.

ATTRIBUTES
       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |ATTRIBUTE TYPE		     |ATTRIBUTE VALUE		   |
       +-----------------------------+-----------------------------+
       |CSI			     |Enabled			   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |MT-Safe			   |
       +-----------------------------+-----------------------------+

SEE ALSO
       _tolower(3C), setlocale(3C), attributes(5), standards(5)

SunOS 5.11							    14 Aug 2002 						       tolower(3C)