ISLOWER(3)             FreeBSD Library Functions Manual             ISLOWER(3)

NAME

     islower, islower_l - 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() and islower_l() functions test 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() or
     iswlower_l() function should be used instead.

SEE ALSO

     ctype(3), ctype_l(3), iswlower(3), iswlower_l(3), tolower(3),
     tolower_l(3), xlocale(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").

HISTORY

     The islower() function first appeared in Version 7 AT&T UNIX.

FreeBSD 15.1-STABLE-HBSD       December 19, 2022                    ISLOWER(3)