Originální popis anglicky:
islower - test for a lowercase letter
Návod, kniha: POSIX Programmer's Manual
#include <ctype.h>
int islower(int
c);
The
islower() function shall test whether
c is a character of
class
lower in the program's current locale; see the Base Definitions
volume of IEEE Std 1003.1-2001, Chapter 7, Locale.
The
c argument is an
int, the value of which the application shall
ensure is a character representable as an
unsigned char or equal to the
value of the macro EOF. If the argument has any other value, the behavior is
undefined.
The
islower() function shall return non-zero if
c is a lowercase
letter; otherwise, it shall return 0.
No errors are defined.
The following sections are informative.
The following example tests whether the value is a lowercase letter, based on
the locale of the user, then uses it as part of a key value.
#include <ctype.h>
#include <stdlib.h>
#include <locale.h>
...
char *keystr;
int elementlen, len;
char c;
...
setlocale(LC_ALL, "");
...
len = 0;
while (len < elementlen) {
c = (char) (rand() % 256);
...
if (islower(c))
keystr[len++] = c;
}
...
To ensure applications portability, especially across natural languages, only
this function and those listed in the SEE ALSO section should be used for
character classification.
None.
None.
isalnum() ,
isalpha() ,
iscntrl() ,
isdigit() ,
isgraph() ,
isprint() ,
ispunct() ,
isspace() ,
isupper() ,
isxdigit() ,
setlocale() , the Base
Definitions volume of IEEE Std 1003.1-2001, Chapter 7, Locale,
<ctype.h>
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
