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?RCS: $Id: i_dirent.U 1 2006-08-24 12:32:52Z rmanfredi $
?RCS:
?RCS: Copyright (c) 1991-1997, 2004-2006, Raphael Manfredi
?RCS: 
?RCS: You may redistribute only under the terms of the Artistic Licence,
?RCS: as specified in the README file that comes with the distribution.
?RCS: You may reuse parts of this distribution only within the terms of
?RCS: that same Artistic Licence; a copy of which may be found at the root
?RCS: of the source tree for dist 4.0.
?RCS:
?RCS: $Log: i_dirent.U,v $
?RCS: Revision 3.0.1.4  1994/10/29  16:20:01  ram
?RCS: patch36: failed scanning for 'd_namlen' with missing <dirent.h> (ADO)
?RCS:
?RCS: Revision 3.0.1.3  1994/06/20  07:01:25  ram
?RCS: patch30: added direntrytype for hints, merely for NeXT (ADO)
?RCS: patch30: now checks for both struct dirent and direct (ADO)
?RCS:
?RCS: Revision 3.0.1.2  1994/05/13  15:22:37  ram
?RCS: patch27: new variable direntrytype for proper type setting (ADO)
?RCS:
?RCS: Revision 3.0.1.1  1994/01/24  14:11:15  ram
?RCS: patch16: added new Direntry_t pseudo-type for directory entries
?RCS:
?RCS: Revision 3.0  1993/08/18  12:08:17  ram
?RCS: Baseline for dist 3.0 netwide release.
?RCS:
?X:
?X: This unit looks whether there is a dirent system or not
?X:
?MAKE:i_dirent d_dirnamlen direntrytype: test contains Setvar \
	Myread Findhdr cppstdin cppflags cppminus rm
?MAKE:	-pick add $@ %<
?S:i_dirent:
?S:	This variable conditionally defines I_DIRENT, which indicates
?S:	to the C program that it should include <dirent.h>.
?S:.
?S:d_dirnamlen:
?S:	This variable conditionally defines DIRNAMLEN, which indicates
?S:	to the C program that the length of directory entry names is
?S:	provided by a d_namelen field.
?S:.
?S:direntrytype:
?S:	This symbol is set to 'struct direct' or 'struct dirent' depending on
?S:	whether dirent is available or not. You should use this pseudo type to
?S:	portably declare your directory entries.
?S:.
?C:I_DIRENT:
?C:	This symbol, if defined, indicates to the C program that it should
?C:	include <dirent.h>. Using this symbol also triggers the definition
?C:	of the Direntry_t define which ends up being 'struct dirent' or
?C:	'struct direct' depending on the availability of <dirent.h>.
?C:.
?C:DIRNAMLEN:
?C:	This symbol, if defined, indicates to the C program that the length
?C:	of directory entry names is provided by a d_namlen field.  Otherwise
?C:	you need to do strlen() on the d_name field.
?C:.
?C:Direntry_t:
?C:	This symbol is set to 'struct direct' or 'struct dirent' depending on
?C:	whether dirent is available or not. You should use this pseudo type to
?C:	portably declare your directory entries.
?C:.
?H:#$i_dirent I_DIRENT		/**/
?H:#$d_dirnamlen DIRNAMLEN	/**/
?H:?%<:@if I_DIRENT && Direntry_t
?H:?%<:#define Direntry_t $direntrytype
?H:?%<:@end
?H:.
?T:xinc guess1 guess2
?LINT:set i_dirent d_dirnamlen
: see if this is a dirent system
echo " "
if xinc=`./findhdr dirent.h`; $test "$xinc"; then
	val="$define"
	echo "<dirent.h> found." >&4
else
	val="$undef"
	if xinc=`./findhdr sys/dir.h`; $test "$xinc"; then
		echo "<sys/dir.h> found." >&4
		echo " "
	else
		xinc=`./findhdr sys/ndir.h`
	fi
	echo "<dirent.h> NOT found." >&4
fi
set i_dirent
eval $setvar

?X: Use struct dirent or struct direct?   If we're using dirent.h, 
?X: it's probably struct dirent, but apparently not always.
?X: Assume $xinc still contains the name of the header file we're using.
@if direntrytype || Direntry_t
: Look for type of directory structure.
echo " "
$cppstdin $cppflags $cppminus < "$xinc" > try.c

case "$direntrytype" in
''|' ')
	case "$i_dirent" in
	$define) guess1='struct dirent' ;;
	*) guess1='struct direct'  ;;
	esac
	;;
*)	guess1="$direntrytype"
	;;
esac

case "$guess1" in
'struct dirent') guess2='struct direct' ;;
*) guess2='struct dirent' ;;
esac
		
if $contains "$guess1" try.c >/dev/null 2>&1; then
	direntrytype="$guess1"
	echo "Your directory entries are $direntrytype." >&4
elif $contains "$guess2" try.c >/dev/null 2>&1; then
	direntrytype="$guess2"
	echo "Your directory entries seem to be $direntrytype." >&4
else
	echo "I don't recognize your system's directory entries." >&4
	rp="What type is used for directory entries on this system?"
	dflt="$guess1"
	. ./myread
	direntrytype="$ans"
fi
$rm -f try.c

@end

@if d_dirnamlen || DIRNAMLEN
: see if the directory entry stores field length
echo " "
$cppstdin $cppflags $cppminus < "$xinc" > try.c
if $contains 'd_namlen' try.c >/dev/null 2>&1; then
	echo "Good, your directory entry keeps length information in d_namlen." >&4
	val="$define"
else
	echo "Your directory entry does not know about the d_namlen field." >&4
	val="$undef"
fi
set d_dirnamlen
eval $setvar
$rm -f try.c

@end