freebsd man page for islower_l

ISLOWER(3)						   BSD Library Functions Manual 						ISLOWER(3)

NAME
     islower -- lower-case character test

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <ctype.h>

     int
     islower(int c);

     int
     islower_l(int c, locale_t loc);

DESCRIPTION
     The islower() function tests for any lower-case letters.  The value of the argument must be representable as an unsigned char or the value of
     EOF.

     In the ASCII character set, this includes the following characters (with their numeric values shown in octal):

     141 ``a''	   142 ``b''	 143 ``c''     144 ``d''     145 ``e''
     146 ``f''	   147 ``g''	 150 ``h''     151 ``i''     152 ``j''
     153 ``k''	   154 ``l''	 155 ``m''     156 ``n''     157 ``o''
     160 ``p''	   161 ``q''	 162 ``r''     163 ``s''     164 ``t''
     165 ``u''	   166 ``v''	 167 ``w''     170 ``x''     171 ``y''
     172 ``z''
     The islower_l() function takes an explicit locale argument, whereas the islower() function uses the current global or per-thread locale.

RETURN VALUES
     The islower() and islower_l() functions return zero if the character tests false and return non-zero if the character tests true.

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 iswlower() function should be used instead.

SEE ALSO
     ctype(3), iswlower(3), tolower(3), ascii(7)

STANDARDS
     The islower() function conforms to ISO/IEC 9899:1990 (``ISO C90'').  The islower_l() function conforms to IEEE Std 1003.1-2008 (``POSIX.1'').

BSD
								   July 30, 2012							       BSD