add libc building to agbcc.

1 files changed, 48 insertions, 0 deletions

diff --git a/libc/ctype/iscntrl.c b/libc/ctype/iscntrl.c
new file mode 100644
index 0000000..7b6da34
--- /dev/null
+++ b/libc/ctype/iscntrl.c
@@ -0,0 +1,48 @@
+
+/*
+FUNCTION
+	<<iscntrl>>---control character predicate
+
+INDEX
+	iscntrl
+
+ANSI_SYNOPSIS
+	#include <ctype.h>
+	int iscntrl(int <[c]>);
+
+TRAD_SYNOPSIS
+	#include <ctype.h>
+	int iscntrl(<[c]>);
+
+DESCRIPTION
+<<iscntrl>> is a macro which classifies ASCII integer values by table
+lookup.  It is a predicate returning non-zero for control characters, and 0 
+for other characters.  It is defined only when <<isascii>>(<[c]>) is
+true or <[c]> is EOF. 
+
+You can use a compiled subroutine instead of the macro definition by
+undefining the macro using `<<#undef iscntrl>>'.
+
+RETURNS
+<<iscntrl>> returns non-zero if <[c]> is a delete character or ordinary
+control character (<<0x7F>> or <<0x00>>--<<0x1F>>).
+
+PORTABILITY
+<<iscntrl>> is ANSI C.
+
+No supporting OS subroutines are required.
+*/
+
+#include <_ansi.h>
+#include <ctype.h>
+
+
+
+#undef iscntrl
+int
+_DEFUN(iscntrl,(c),int c)
+{
+	return((_ctype_ + 1)[c] & _C);
+}
+
+