| TOLOWER(3) | Library Functions Manual | TOLOWER(3) | 
NAME
 tolower — upper case to lower case letter conversion
LIBRARY
 Standard C Library (libc, -lc)
SYNOPSIS
 #include <ctype.h>
int
tolower(int c);
 
DESCRIPTION
 The tolower() function converts an upper-case letter to the corresponding lower-case letter.
RETURN VALUES
 If the argument is an upper-case letter, the tolower() function returns the corresponding lower-case letter if there is one; otherwise the argument is returned unchanged.
SEE ALSO
 ctype(3), 
isalnum(3), 
isalpha(3), 
isascii(3), 
iscntrl(3), 
isdigit(3), 
isgraph(3), 
islower(3), 
isprint(3), 
ispunct(3), 
isspace(3), 
isupper(3), 
isxdigit(3), 
stdio(3), 
toascii(3), 
toupper(3), 
ascii(7) 
STANDARDS
 The tolower() function conforms to ANSI X3.159-1989 (“ANSI C89”).
CAVEATS
 The argument to 
tolower() must be 
EOF or representable as an 
unsigned char; otherwise, the behavior is undefined. See the 
CAVEATS section of 
ctype(3) for more details.