TOLOWER(3) Library Functions Manual TOLOWER(3)
NAME
tolowerupper 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
STANDARDS
The tolower() function conforms to ANSI X3.159-1989 (“ANSI C”).
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.