🚀 go-pugleaf

Can someone answer me?  Why gcc a file containing a line of 
"#define O_TEXT 4" , it gives the following strange error. (See j.out 
below)

C> gcc -c -DMSDOS j.c 
c:/tmp/cc000046.i:1: parse error before `file'
c:/tmp/cc000046.i:42: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:42: warning: unknown escape sequence `\c'
 (   ...  )
++++++++++++++++++++++++++++  j.c +++++++++++++++++++++++++++++++++++++
#include "fig.h"
#include "junk.h"
++++++++++++++++++++++++++++  junk.h +++++++++++++++++++++++++++++++++++++
#define		O_TEXT			4
++++++++++++++++++++++++++++  fig.h +++++++++++++++++++++++++++++++++++++
/*
 * FIG : Facility for Interactive Generation of figures
 * Copyright (c) 1985 by Supoj Sutanthavibul
 *
 * "Permission to use, copy, modify, distribute, and sell this software and its
 * documentation for any purpose is hereby granted without fee, provided that
 * the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in advertising or
 * publicity pertaining to distribution of the software without specific,
 * written prior permission.  M.I.T. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty."
 *
 */

#include <X11/Xos.h>

#include <sys/stat.h>
#ifndef SYSV
#include <fcntl.h>
#endif
#include <pwd.h>
#include <signal.h>

#include <stdio.h>
#include <ctype.h>
#include <errno.h>

extern int      errno;
extern int      sys_nerr;
extern char    *sys_errlist[];

#include <math.h>

#ifdef SYSV
#define u_int uint
#endif

#ifndef M_PI
#define M_PI    3.14159265358979323846
#define M_PI_2  1.57079632679489661923
#endif

#define		min2(a, b)	(((a) < (b)) ? (a) : (b))
#define		max2(a, b)	(((a) > (b)) ? (a) : (b))
#define		min3(a,b,c)	((((a<b)?a:b)<c)?((a<b)?a:b):c)
#define		max3(a,b,c)	((((a>b)?a:b)>c)?((a>b)?a:b):c)
#define		round(a)	(int)((a)+.5)
#define		signof(a)	(((a) < 0) ? -1 : 1)

#define		DEF_NAME	"unnamed.fig"

#include <X11/Xlib.h>
#ifdef MSDOS
#include <X11/cursorfo.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/cursorfont.h>
#endif
#ifdef MSDOS
#include <X11/Intrinsc.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/Intrinsic.h>
#endif
#ifdef MSDOS
#include <X11/StringDe.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/StringDefs.h>
#endif
#include <X11/Shell.h>

#include <X11/Xaw/Command.h>
#include <X11/Xaw/Label.h>
#include <X11/Xaw/Dialog.h>
#include <X11/Xaw/Box.h>
#include <X11/Xaw/Form.h>
#ifdef MSDOS
#include <X11/Xaw/Cardinal.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/Xaw/Cardinals.h>
#endif
#include <X11/Xaw/Text.h>
#ifdef MSDOS
#include <X11/Xaw/AsciiTex.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/Xaw/AsciiText.h>
#endif
#ifdef MSDOS
#include <X11/Xaw/MenuButt.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/Xaw/MenuButton.h>
#endif
#ifdef MSDOS
#include <X11/Xaw/SimpleMe.h>      /* QDK 01/06/1993  6:26pm. */
#else
#include <X11/Xaw/SimpleMenu.h>
#endif
#include <X11/Xaw/Sme.h>
#include <X11/Xaw/SmeBSB.h>
#include <X11/Xaw/Toggle.h>
++++++++++++++++++++++++++++++ j.out ++++++++++++++++++++++++++++++++
c:/tmp/cc000046.i:1: parse error before `file'
c:/tmp/cc000046.i:42: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:42: warning: unknown escape sequence `\c'
c:/tmp/cc000046.i:42: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:42: warning: unknown escape sequence `\i'
c:/tmp/cc000046.i:77: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:77: warning: unknown escape sequence `\c'
c:/tmp/cc000046.i:77: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:77: warning: unknown escape sequence `\i'
 ( ... lots and lots of similar lines)
c:/tmp/cc000046.i:14993: warning: unknown escape sequence `\i'
c:/tmp/cc000046.i:15148: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:15148: warning: unknown escape sequence `\c'
c:/tmp/cc000046.i:15148: warning: unknown escape sequence `\d'
c:/tmp/cc000046.i:15148: warning: unknown escape sequence `\i'
c:/tmp/cc000046.i:15161: malformatted character constant

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