NAME
islower —
lower-case character test
LIBRARY
library “libc”
SYNOPSIS
#include
<ctype.h>
int
islower(int
c);
int
islower_l(int
c, locale_t
loc);
DESCRIPTION
Theislower()
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'' |
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
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”).