0,0 → 1,44 |
/* |
FUNCTION |
<<isalpha>>---alphabetic character predicate |
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INDEX |
isalpha |
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ANSI_SYNOPSIS |
#include <ctype.h> |
int isalpha(int <[c]>); |
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TRAD_SYNOPSIS |
#include <ctype.h> |
int isalpha(<[c]>); |
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DESCRIPTION |
<<isalpha>> is a macro which classifies ASCII integer values by table |
lookup. It is a predicate returning non-zero when <[c]> represents an |
alphabetic ASCII character, and 0 otherwise. It is defined only when |
<<isascii>>(<[c]>) is true or <[c]> is EOF. |
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You can use a compiled subroutine instead of the macro definition by |
undefining the macro using `<<#undef isalpha>>'. |
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RETURNS |
<<isalpha>> returns non-zero if <[c]> is a letter (<<A>>--<<Z>> or |
<<a>>--<<z>>). |
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PORTABILITY |
<<isalpha>> is ANSI C. |
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No supporting OS subroutines are required. |
*/ |
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#include <_ansi.h> |
#include <ctype.h> |
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#undef isalpha |
int |
_DEFUN(isalpha,(c),int c) |
{ |
return(__ctype_ptr__[c+1] & (_U|_L)); |
} |
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