forked from KolibriOS/kolibrios
47 lines
971 B
C
47 lines
971 B
C
/*
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FUNCTION
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<<isalnum>>---alphanumeric character predicate
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INDEX
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isalnum
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ANSI_SYNOPSIS
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#include <ctype.h>
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int isalnum(int <[c]>);
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TRAD_SYNOPSIS
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#include <ctype.h>
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int isalnum(<[c]>);
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DESCRIPTION
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<<isalnum>> is a macro which classifies ASCII integer values by table
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lookup. It is a predicate returning non-zero for alphabetic or
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numeric ASCII characters, and <<0>> for other arguments. It is defined
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only if <[c]> is representable as an unsigned char or if <[c]> is EOF.
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You can use a compiled subroutine instead of the macro definition by
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undefining the macro using `<<#undef isalnum>>'.
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RETURNS
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<<isalnum>> returns non-zero if <[c]> is a letter (<<a>>--<<z>> or
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<<A>>--<<Z>>) or a digit (<<0>>--<<9>>).
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PORTABILITY
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<<isalnum>> is ANSI C.
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No OS subroutines are required.
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*/
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#include <_ansi.h>
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#include <ctype.h>
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#undef isalnum
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int
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_DEFUN(isalnum,(c),int c)
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{
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return(__ctype_ptr__[c+1] & (_U|_L|_N));
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}
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