ISLOWER(3) |
FreeBSD 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'' |
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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.
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”).