?X:  These units are based on the ones supplied with dist-3.0
?X:  patchlevel 22.  They have been changed or enhanced to work with
?X:  perl5alpha.  I would appreciate hearing about any changes,
?X:  corrections, or enhancements.
?X:	Andy Dougherty			doughera@lafcol.lafayette.edu
?X:	Dept. of Physics 		
?X:	Lafayette College	
?X:	Easton, PA  18042-1782
?X:     Sat Apr  2 15:45:17 EST 1994
?RCS: $Id: d_strerror.U,v 3.0.1.1 1994/01/24 14:08:56 ram Exp $
?RCS:
?RCS: Copyright (c) 1991-1993, 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 3.0.
?RCS:
?RCS: $Log: d_strerror.U,v $
?RCS: Revision 3.0.1.1  1994/01/24  14:08:56  ram
?RCS: patch16: protected code looking for sys_errnolist[] with @if
?RCS: patch16: added default value for d_sysernlst
?RCS:
?RCS: Revision 3.0  1993/08/18  12:07:35  ram
?RCS: Baseline for dist 3.0 netwide release.
?RCS:
?MAKE:d_strerror d_syserrlst d_sysernlst d_strerrm: contains Csym Findhdr
?MAKE:	-pick add $@ %<
?S:d_strerror:
?S:	This variable conditionally defines HAS_STRERROR if strerror() is
?S:	available to translate error numbers to strings.
?S:.
?S:d_syserrlst:
?S:	This variable conditionally defines HAS_SYS_ERRLIST if sys_errlist[] is
?S:	available to translate error numbers to strings.
?S:.
?S:d_sysernlst:
?S:	This variable conditionally defines HAS_SYS_ERRNOLIST if sys_errnolist[]
?S:	is available to translate error numbers to the symbolic name.
?S:.
?S:d_strerrm:
?S:	This variable conditionally defines strerrr as a macro if the
?S:	sys_errlist[] array is defined.
?S:.
?C:HAS_STRERROR (STRERROR):
?C:	This symbol, if defined, indicates that the strerror routine is
?C:	available to translate error numbers to strings. See the writeup
?C:	of Strerror() in this file before you try to define your own.
?C:.
?C:HAS_SYS_ERRLIST (SYSERRLIST):
?C:	This symbol, if defined, indicates that the sys_errlist array is
?C:	available to translate error numbers to strings. The extern int
?C:	sys_nerr gives the size of that table.
?C:.
?C:HAS_SYS_ERRNOLIST (SYSERRNOLIST):
?C:	This symbol, if defined, indicates that the sys_errnolist array is
?C:	available to translate an errno code into its symbolic name (e.g.
?C: ENOENT). The extern int sys_nerrno gives the size of that table.
?C:.
?C:Strerror:
?C:	This preprocessor symbol is defined as a macro if strerror() is
?C:	not available to translate error numbers to strings but sys_errlist[]
?C:	array is there.
?C:.
?H:#$d_strerror HAS_STRERROR		/**/
?H:#$d_syserrlst HAS_SYS_ERRLIST	/**/
?H:#$d_sysernlst HAS_SYS_ERRNOLIST	/**/
?H:?%<:#ifdef HAS_STRERROR
?H:?%<:#  define Strerror strerror
?H:?%<:#else
?H:#$d_strerrm Strerror(e) ((e)<0||(e)>=sys_nerr?"unknown":sys_errlist[e]) /**/
?H:?%<:#endif
?H:.
?D:d_sysernlst=''
?T:xxx val
: see if strerror and/or sys_errlist[] exist
echo " "
if set strerror val -f d_strerror; eval $csym; $val; then
	echo 'strerror() found.' >&4
	d_strerror="$define"
	d_strerrm="$undef"
	if set sys_errlist val -a d_syserrlst; eval $csym; $val; then	
		echo "(You also have sys_errlist[], so we could roll our own strerror.)" 
		d_syserrlst="$define"
	else
	echo "(Since you don't have sys_errlist[], sterror() is welcome.)"
		d_syserrlst="$undef"
	fi
elif xxx=`./findhdr string.h`; test "$xxx" || xxx=`./findhdr strings.h`; \
	$contains '#[ 	]*define.*strerror' "$xxx" >/dev/null 2>&1; then
	echo 'strerror() found in string header.' >&4
	d_strerror="$define"
	d_strerrm="$undef"
	if set sys_errlist val -a d_syserrlst; eval $csym; $val; then	
		echo "(Most probably, strerror() uses sys_errlist[] for descriptions.)"
		d_syserrlst="$define"
	else
		echo "(You don't appear to have any sys_errlist[], how can this be?)"
		d_syserrlst="$undef"
	fi
elif set sys_errlist val -a d_syserrlst; eval $csym; $val; then
echo "strerror() not found, but you have sys_errlist[] so we'll use that." >&4
	d_strerror="$undef"
	d_syserrlst="$define"
	d_strerrm="$define"
else
	echo 'strerror() and sys_errlist[] NOT found.' >&4
	d_strerror="$undef"
	d_syserrlst="$undef"
	d_strerrm="$undef"
fi
@if d_sysernlst || HAS_SYS_ERRNOLIST
if set sys_errnolist val -a d_sysernlst; eval $csym; $val; then
	echo "(Symbolic error codes can be fetched via the sys_errnolist[] array.)"
	d_sysernlst="$define"
else
	echo "(However, I can't extract the symbolic error code out of errno.)"
	d_sysernlst="$undef"
fi
@end