TOLOWER(3) |
FreeBSD 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. The argument must be representable as an
unsigned char or the value of
EOF.
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.
COMPATIBILITY
The
4.4BSD extension of accepting arguments outside of the range of the
unsigned char type in locales with large character sets is considered obsolete and may not be supported in future releases. The
towlower() function should be used instead.
STANDARDS
The
tolower() function conforms to ISO/IEC 9899:1990 (“ISO C90”).