postdmd.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

 *
 * Handles things that must be done after the options are read but before the
 * input files are processed.
 *
 */

    writerequest(0, stdout);		/* global requests eg. manual feed */
    setencoding(fontencoding);		/* unnecessary */
    fprintf(stdout, "setup\n");

    if ( formsperpage > 1 )  {		/* followed by stuff for multiple pages */
	if ( cat(formfile) == FALSE )
	    error(FATAL, "can't read %s", formfile);
	fprintf(stdout, "%d setupforms\n", formsperpage);
    }	/* End if */

    fprintf(stdout, "%s", ENDSETUP);

}   /* End of setup */

/*****************************************************************************/

arguments()

{

    FILE	*fp;			/* next input file */

/*
 *
 * Makes sure all the non-option command line arguments are processed. If we get
 * here and there aren't any arguments left, or if '-' is one of the input files
 * we'll process stdin.
 *
 */

    if ( argc < 1 )
	bitmap(stdin);
    else  {				/* at least one argument is left */
	while ( argc > 0 )  {
	    if ( strcmp(*argv, "-") == 0 )
		fp = stdin;
	    else if ( (fp = fopen(*argv, "r")) == NULL )
		error(FATAL, "can't open %s", *argv);
	    bitmap(fp);
	    if ( fp != stdin )
		fclose(fp);
	    argc--;
	    argv++;
	}   /* End while */
    }   /* End else */

}   /* End of arguments */

/*****************************************************************************/

done()

{

/*
 *
 * Finished with all the input files, so mark the end of the pages with a TRAILER
 * comment, make sure the last page prints, and add things like the PAGES comment
 * that can only be determined after all the input files have been read.
 *
 */

    fprintf(stdout, "%s", TRAILER);
    fprintf(stdout, "done\n");
    fprintf(stdout, "%s 0 0 %d %d\n", BOUNDINGBOX, (bbox[0]*72+100)/100, (bbox[1]*72+100)/100);
    fprintf(stdout, "%s %d\n", PAGES, printed);

}   /* End of done */

/*****************************************************************************/

account()

{

/*
 *
 * Writes an accounting record to *fp_acct provided it's not NULL. Accounting is
 * requested using the -A or -J options.
 *
 */

    if ( fp_acct != NULL )
	fprintf(fp_acct, " print %d\n copies %d\n", printed, copies);

}   /* End of account */

/*****************************************************************************/

bitmap(fp)

    FILE	*fp;			/* next input file */

{

    int		count;			/* pattern repeats this many times */
    long	total;			/* expect this many patterns */

/*
 *
 * Reads all the bitmaps from the next input file, translates each one into
 * PostScript, and arranges to have one bitmap printed on each page. Multiple
 * bitmaps per input file work.
 *
 */

    fp_in = fp;				/* everyone reads from this file */

    while ( dimensions() == TRUE )  {
	patcount = 0;
	total = scanlines * patterns;

	bbox[0] = MAX(bbox[0], patterns*16);	/* for BoundingBox comment */
	bbox[1] = MAX(bbox[1], scanlines);

	redirect(++page);
	fprintf(fp_out, "%s %d %d\n", PAGE, page, printed+1);
	fprintf(fp_out, "/saveobj save def\n");
	writerequest(printed+1, fp_out);

	fprintf(fp_out, "%s ", (v8format == TRUE && v8undo == FALSE) ? "true" : "false");
	fprintf(fp_out, "%s ", (flip == TRUE) ? "true" : "false");
	fprintf(fp_out, "%d %d bitmap\n", patterns * 16, scanlines);

	while ( patcount != total && (count = getc(fp)) != EOF )  {
	    addrast(count);
	    patcount += (count & 0177);
	    if ( patcount % patterns == 0 )
		putrast();
	}   /* End while */

	if ( debug == ON )
	    fprintf(stderr, "patterns = %d, scanlines = %d, patcount = %d\n", patterns, scanlines, patcount);

	if ( total != patcount )
	    error(FATAL, "bitmap format error");

	if ( fp_out == stdout ) printed++;

	fprintf(fp_out, "showpage\n");
	fprintf(fp_out, "saveobj restore\n");
	fprintf(fp_out, "%s %d %d\n", ENDPAGE, page, printed);
    }	/* End while */

}   /* End of bitmap */

/*****************************************************************************/

dimensions()

{

    int		ox, oy;			/* coordinates of the origin */
    int		cx, cy;			/* and right corner of the bitmap */
    int		i;			/* loop index */

/*
 *
 * Determines the dimensions and type of the next bitmap. Eighth edition bitmaps
 * have a zero in the first 16 bits. If valid dimensions are read TRUE is returned
 * to the caller. Changed so the check of whether we're done (by testing scanlines
 * or patterns) comes before the malloc().
 *
 */

    if ( (scanlines = getint()) == 0 )  {
	ox = getint();
	oy = getint();
	cx = getint();
	cy = getint();
	scanlines = cy - oy;
	patterns = (cx - ox + 15) / 16;
	v8format = TRUE;
    } else patterns = getint();

    if ( scanlines <= 0 || patterns <= 0 )	/* done - don't do the malloc() */
	return(FALSE);

    if ( raster != NULL ) free(raster);
    if ( prevrast != NULL ) free(prevrast);

    if ( (rptr = raster = (char *) malloc(patterns * 2)) == NULL )
	error(FATAL, "no memory");

    if ( (prevrast = (char *) malloc(patterns * 2)) == NULL )
	error(FATAL, "no memory");

    for ( i = 0; i < patterns * 2; i++ )
	*(prevrast+i) = 0377;

    eptr = rptr + patterns * 2;

    return(TRUE);

}   /* End of dimensions */

/*****************************************************************************/

addrast(count)

    int		count;			/* repeat count for next pattern */

{

    int		size;			/* number of bytes in next pattern */
    int		l, h;			/* high and low bytes */
    int		i, j;			/* loop indices */

/*
 *
 * Reads the input file and adds the appropriate number of bytes to the output
 * raster line. If count has bit 7 on, one 16 bit pattern is read and repeated
 * count & 0177 times. If bit 7 is off, count is the number of patterns read from
 * fp_in - each one repeated once.
 *
 */

    if ( count & 0200 )  {
	size = 1;
	count &= 0177;
    } else {
	size = count;
	count = 1;
    }	/* End else */

    for ( i = size; i > 0; i-- )  {
	if ( (l = getc(fp_in)) == EOF || (h = getc(fp_in)) == EOF )
	    return;
	for ( j = count; j > 0; j-- )  {
	    *rptr++ = l;
	    *rptr++ = h;
	}   /* End for */
    }	/* End for */

}   /* End of addrast */

/*****************************************************************************/

putrast()

{

    char	*p1, *p2;		/* starting and ending patterns */
    int		n;			/* set to bytes per pattern */
    int		i;			/* loop index */

/*
 *
 * Takes the scanline that's been saved in *raster, encodes it according to the
 * value that's been assigned to bytespp, and writes the result to *fp_out. Each
 * line in the output bitmap is terminated by a 0 on a line by itself.
 *
 */

    n = (bytespp <= 0) ? 2 * patterns : bytespp;

    if ( v8format == TRUE && v8undo == TRUE )
	for ( i = 0; i < patterns * 2; i++ )
	    *(raster+i) = (*(prevrast+i) ^= *(raster+i));

    for ( p1 = raster, p2 = raster + n; p1 < eptr; p1 = p2 )
	if ( patncmp(p1, n) == TRUE )  {
	    while ( patncmp(p2, n) == TRUE ) p2 += n;
	    p2 += n;
	    fprintf(fp_out, "%d ", n);
	    for ( i = 0; i < n; i++, p1++ )
		fprintf(fp_out, "%.2X", ((int) *p1) & 0377);
	    fprintf(fp_out, " %d\n", (p2 - p1) / n);
	} else {
	    while ( p2 < eptr && patncmp(p2, n) == FALSE ) p2 += n;
	    if ( p2 > eptr ) p2 = eptr;
	    fprintf(fp_out, "%d ", p2 - p1);
	    while ( p1 < p2 )
		fprintf(fp_out, "%.2X", ((int) *p1++) & 0377);
	    fprintf(fp_out, " 0\n");
	}   /* End else */

    fprintf(fp_out, "0\n");

    rptr = raster;

}   /* End of putrast */

/*****************************************************************************/

patncmp(p1, n)

    char	*p1;			/* first patterns starts here */
    int		n;			/* and extends this many bytes */

{

    char	*p2;			/* address of the second pattern */

/*
 *
 * Compares the two n byte patterns *p1 and *(p1+n). FALSE is returned if they're
 * different or extend past the end of the current raster line.
 *
 */

    p2 = p1 + n;

    for ( ; n > 0; n--, p1++, p2++ )
	if ( p2 >= eptr || *p1 != *p2 )
	    return(FALSE);

    return(TRUE);

}   /* End of patncmp */

/*****************************************************************************/

getint()

{

    int		h, l;			/* high and low bytes */

/*
 *
 * Reads the next two bytes from *fp_in and returns the resulting integer.
 *
 */

    if ( (l = getc(fp_in)) == EOF || (h = getc(fp_in)) == EOF )
	return(-1);

    return((h & 0377) << 8 | (l & 0377));

}   /* End of getint */

/*****************************************************************************/

redirect(pg)

    int		pg;			/* next page we're printing */

{

    static FILE	*fp_null = NULL;	/* if output is turned off */

/*
 *
 * If we're not supposed to print page pg, fp_out will be directed to /dev/null,
 * otherwise output goes to stdout.
 *
 */

    if ( pg >= 0 && in_olist(pg) == ON )
	fp_out = stdout;
    else if ( (fp_out = fp_null) == NULL )
	fp_out = fp_null = fopen("/dev/null", "w");

}   /* End of redirect */

/*****************************************************************************/