postdaisy.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

/*
 *
 * postdaisy - PostScript translator for Diablo 1640 files.
 *
 * A program that translates Diablo 1640 files into PostScript. Absolutely nothing
 * is guaranteed. Quite a few things haven't been implemented, and what's been
 * done isn't well tested. Most of the documentation used to write this program
 * was taken from the 'Diablo Emulator' section of a recent Imagen manual.
 *
 * Some of document comments that are generated may not be right. Most of the test
 * files I used produced a trailing blank page. I've put a check in formfeed() that
 * won't print the last page if it doesn't contain any text, but PAGES comments may
 * not be right. The DOCUMENTFONTS comment will also be wrong if auto underline or
 * bold printing have been turned on by escape commands.
 *
 * The brute force approach used to implement horizontal and vertical tabs leaves
 * much to be desired, and may not work for very small initial hmi and vmi values.
 * At the very least I should have used malloc() to get space for the two tabstop
 * arrays after hmi and vmi are known!
 *
 * Reverse printing mode hasn't been tested at all, but what's here should be
 * close even though it's not efficient.
 *
 * The PostScript prologue is copied from *prologue before any of the input files
 * are translated. The program expects that the following PostScript procedures
 * are defined in that file:
 *
 *	setup
 *
 *	  mark ... setup -
 *
 *	    Handles special initialization stuff that depends on how this program
 *	    was called. Expects to find a mark followed by key/value pairs on the
 *	    stack. The def operator is applied to each pair up to the mark, then
 *	    the default state is set up.
 *
 *	pagesetup
 *
 *	  page pagesetup -
 *
 *	    Does whatever is needed to set things up for the next page. Expects to
 *	    find the current page number on the stack.
 *
 *	t
 *
 *	  mark str1 x1 str2 x2 ... strn xn y hmi t mark
 *
 *	    Handles all the text on the stack. Characters in the strings are
 *	    printed using hmi as the character advance, and all strings are at
 *	    vertical position y. Each string is begins at the horizontal position
 *	    that preceeds it.
 *
 *	f
 *
 *	  font f -
 *
 *	    Use font f, where f is the full PostScript font name. Only used when
 *	    we switch to auto underline (Courier-Italic) or bold (Courier-Bold)
 *	    printing.
 *
 *	done
 *
 *	  done
 *
 *	    Makes sure the last page is printed. Only needed when we're printing
 *	    more than one page on each sheet of paper.
 *
 * Many default values, like the magnification and orientation, are defined in 
 * the prologue, which is where they belong. If they're changed (by options), an
 * appropriate definition is made after the prologue is added to the output file.
 * The -P option passes arbitrary PostScript through to the output file. Among
 * other things it can be used to set (or change) values that can't be accessed by
 * other options.
 *
 */

#include <stdio.h>
#include <signal.h>
#include <ctype.h>
#ifdef plan9
#define	isascii(c)	((unsigned char)(c)<=0177)
#endif
#include <sys/types.h>
#include <fcntl.h>

#include "comments.h"			/* PostScript file structuring comments */
#include "gen.h"			/* general purpose definitions */
#include "path.h"			/* for the prologue */
#include "ext.h"			/* external variable declarations */
#include "postdaisy.h"			/* a few special definitions */

char	*optnames = "a:c:f:h:l:m:n:o:p:r:s:v:x:y:A:C:E:J:L:P:DI";

char	*prologue = POSTDAISY;		/* default PostScript prologue */
char	*formfile = FORMFILE;		/* stuff for multiple pages per sheet */

int	formsperpage = 1;		/* page images on each piece of paper */
int	copies = 1;			/* and this many copies of each sheet */

char	htabstops[COLUMNS];		/* horizontal */
char	vtabstops[ROWS];		/* and vertical tabs */

int	res = RES;			/* input file resolution - sort of */

int	hmi = HMI;			/* horizontal motion index - 1/120 inch */
int	vmi = VMI;			/* vertical motion index - 1/48 inch */
int	ohmi = HMI;			/* original hmi */
int	ovmi = VMI;			/* and vmi - for tabs and char size */

int	hpos = 0;			/* current horizontal */
int	vpos = 0;			/* and vertical position */

int	lastx = -1;			/* printer's last horizontal */
int	lasty = -1;			/* and vertical position */
int	lasthmi = -1;			/* hmi for current text strings */

int	lastc = -1;			/* last printed character */
int	prevx = -1;			/* at this position */

int	leftmargin = LEFTMARGIN;	/* page margins */
int	rightmargin = RIGHTMARGIN;
int	topmargin = TOPMARGIN;
int	bottommargin = BOTTOMMARGIN;

int	stringcount = 0;		/* number of strings on the stack */
int	stringstart = 1;		/* column where current one starts */
int	advance = 1;			/* -1 if in backward print mode */

int	lfiscr = OFF;			/* line feed implies carriage return */
int	crislf = OFF;			/* carriage return implies line feed */

int	linespp = 0;			/* lines per page if it's positive */
int	markedpage = FALSE;		/* helps prevent trailing blank page */
int	page = 0;			/* page we're working on */
int	printed = 0;			/* printed this many pages */

Fontmap	fontmap[] = FONTMAP;		/* for translating font names */
char	*fontname = "Courier";		/* use this PostScript font */
int	shadowprint = OFF;		/* automatic bold printing if ON */

FILE	*fp_in;				/* read from this file */
FILE	*fp_out = stdout;		/* and write stuff here */
FILE	*fp_acct = NULL;		/* for accounting data */

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

main(agc, agv)

    int		agc;
    char	*agv[];

{

/*
 *
 * A simple program that translates Diablo 1640 files into PostScript. Nothing
 * is guaranteed - the program not well tested and doesn't implement everything.
 *
 */

    argc = agc;				/* other routines may want them */
    argv = agv;

    prog_name = argv[0];		/* really just for error messages */

    init_signals();			/* sets up interrupt handling */
    header();				/* PostScript header comments */
    options();				/* handle the command line options */
    setup();				/* for PostScript */
    arguments();			/* followed by each input file */
    done();				/* print the last page etc. */
    account();				/* job accounting data */

    exit(x_stat);			/* not much could be wrong */

}   /* End of main */

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

init_signals()

{

/*
 *
 * Makes sure we handle interrupts.
 *
 */

    if ( signal(SIGINT, interrupt) == SIG_IGN )  {
	signal(SIGINT, SIG_IGN);
	signal(SIGQUIT, SIG_IGN);
	signal(SIGHUP, SIG_IGN);
    } else {
	signal(SIGHUP, interrupt);
	signal(SIGQUIT, interrupt);
    }   /* End else */

    signal(SIGTERM, interrupt);

}   /* End of init_signals */

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

header()

{

    int		ch;			/* return value from getopt() */
    int		old_optind = optind;	/* for restoring optind - should be 1 */

/*
 *
 * Scans the option list looking for things, like the prologue file, that we need
 * right away but could be changed from the default. Doing things this way is an
 * attempt to conform to Adobe's latest file structuring conventions. In particular
 * they now say there should be nothing executed in the prologue, and they have
 * added two new comments that delimit global initialization calls. Once we know
 * where things really are we write out the job header, follow it by the prologue,
 * and then add the ENDPROLOG and BEGINSETUP comments.
 *
 */

    while ( (ch = getopt(argc, argv, optnames)) != EOF )
	if ( ch == 'L' )
	    prologue = optarg;
	else if ( ch == '?' )
	    error(FATAL, "");

    optind = old_optind;		/* get ready for option scanning */

    fprintf(stdout, "%s", CONFORMING);
    fprintf(stdout, "%s %s\n", VERSION, PROGRAMVERSION);
    fprintf(stdout, "%s %s\n", DOCUMENTFONTS, ATEND);
    fprintf(stdout, "%s %s\n", PAGES, ATEND);
    fprintf(stdout, "%s", ENDCOMMENTS);

    if ( cat(prologue) == FALSE )
	error(FATAL, "can't read %s", prologue);

    if ( DOROUND )
	cat(ROUNDPAGE);

    fprintf(stdout, "%s", ENDPROLOG);
    fprintf(stdout, "%s", BEGINSETUP);
    fprintf(stdout, "mark\n");

}   /* End of header */

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

options()

{

    int		ch;			/* return value from getopt() */
    int		n;			/* for CR and LF modes */

/*
 *
 * Reads and processes the command line options. Added the -P option so arbitrary
 * PostScript code can be passed through. Expect it could be useful for changing
 * definitions in the prologue for which options have not been defined.
 *
 * Although any PostScript font can be used, things will only work for constant
 * width fonts.
 *
 */

    while ( (ch = getopt(argc, argv, optnames)) != EOF )  {
	switch ( ch )  {
	    case 'a':			/* aspect ratio */
		    fprintf(stdout, "/aspectratio %s def\n", optarg);
		    break;

	    case 'c':			/* copies */
		    copies = atoi(optarg);
		    fprintf(stdout, "/#copies %s store\n", optarg);
		    break;

	    case 'f':			/* use this PostScript font */
		    fontname = get_font(optarg);
		    fprintf(stdout, "/font /%s def\n", fontname);
		    break;

	    case 'h':			/* default character spacing */
		    ohmi = hmi = atoi(optarg) * HSCALE;
		    fprintf(stdout, "/hmi %s def\n", optarg);
		    break;

	    case 'l':			/* lines per page */
		    linespp = atoi(optarg);
		    break;

	    case 'm':			/* magnification */
		    fprintf(stdout, "/magnification %s def\n", optarg);
		    break;

	    case 'n':			/* forms per page */
		    formsperpage = atoi(optarg);
		    fprintf(stdout, "%s %s\n", FORMSPERPAGE, optarg);
		    fprintf(stdout, "/formsperpage %s def\n", optarg);
		    break;

	    case 'o':			/* output page list */
		    out_list(optarg);
		    break;

	    case 'p':			/* landscape or portrait mode */
		    if ( *optarg == 'l' )
			fprintf(stdout, "/landscape true def\n");
		    else fprintf(stdout, "/landscape false def\n");
		    break;

	    case 'r':			/* set CR and LF modes */
		    n = atoi(optarg);
		    if ( n & 01 )
			lfiscr = ON;
		    else lfiscr = OFF;
		    if ( n & 02 )
			crislf = ON;
		    else crislf = OFF;
		    break;

	    case 's':			/* point size */
		    fprintf(stdout, "/pointsize %s def\n", optarg);
		    break;

	    case 'v':			/* default line spacing */
		    ovmi = vmi = atoi(optarg) * VSCALE;
		    break;

	    case 'x':			/* shift things horizontally */
		    fprintf(stdout, "/xoffset %s def\n", optarg);
		    break;

	    case 'y':			/* and vertically on the page */
		    fprintf(stdout, "/yoffset %s def\n", optarg);
		    break;

	    case 'A':			/* force job accounting */
	    case 'J':
		    if ( (fp_acct = fopen(optarg, "a")) == NULL )
			error(FATAL, "can't open accounting file %s", optarg);
		    break;

	    case 'C':			/* copy file straight to output */
		    if ( cat(optarg) == FALSE )
			error(FATAL, "can't read %s", optarg);
		    break;

	    case 'E':			/* text font encoding */
		    fontencoding = optarg;
		    break;

	    case 'L':			/* PostScript prologue file */
		    prologue = optarg;
		    break;

	    case 'P':			/* PostScript pass through */
		    fprintf(stdout, "%s\n", optarg);
		    break;

	    case 'R':			/* special global or page level request */
		    saverequest(optarg);
		    break;

	    case 'D':			/* debug flag */
		    debug = ON;
		    break;

	    case 'I':			/* ignore FATAL errors */
		    ignore = ON;
		    break;

	    case '?':			/* don't understand the option */
		    error(FATAL, "");
		    break;

	    default:			/* don't know what to do for ch */
		    error(FATAL, "missing case for option %c\n", ch);
		    break;
	}   /* End switch */
    }   /* End while */

    argc -= optind;			/* get ready for non-option args */
    argv += optind;

}   /* End of options */

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

char *get_font(name)

    char	*name;			/* name the user asked for */

{

    int		i;			/* for looking through fontmap[] */

/*
 *
 * Called from options() to map a user's font name into a legal PostScript name.
 * If the lookup fails *name is returned to the caller. That should let you choose
 * any PostScript font, although things will only work well for constant width
 * fonts.
 *
 */

    for ( i = 0; fontmap[i].name != NULL; i++ )
	if ( strcmp(name, fontmap[i].name) == 0 )
	    return(fontmap[i].val);

    return(name);

}   /* End of get_font */

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

setup()

{

/*
 *
 * 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);
    fprintf(stdout, "setup\n");

    if ( formsperpage > 1 )  {
	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()

{

/*
 *
 * 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.
 *
 */

    fp_in = stdin;

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

}   /* End of arguments */

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

done()

{

/*
 *
 * Finished with all the input files, so mark the end of the pages, make sure the
 * last page is printed, and restore the initial environment.
 *
 */

    fprintf(stdout, "%s", TRAILER);
    fprintf(stdout, "done\n");
    fprintf(stdout, "%s %s\n", DOCUMENTFONTS, fontname);
    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 */

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

text()

{

    int		ch;			/* next input character */

/*
 *
 * Translates the next input file into PostScript. The redirect(-1) call forces
 * the initial output to go to /dev/null - so the stuff formfeed() does at the
 * end of each page doesn't go to stdout.
 *
 */

    redirect(-1);			/* get ready for the first page */
    formfeed();				/* force PAGE comment etc. */
    inittabs();

    while ( (ch = getc(fp_in)) != EOF )
	switch ( ch )  {
	    case '\010':		/* backspace */
		    backspace();
		    break;

	    case '\011':		/* horizontal tab */
		    htab();
		    break;

	    case '\012':		/* new line */
		    linefeed();
		    break;

	    case '\013':		/* vertical tab */
		    vtab();
		    break;

	    case '\014':		/* form feed */
		    formfeed();
		    break;

	    case '\015':		/* carriage return */
		    carriage();
		    break;

	    case '\016':		/* extended character set - SO */
		    break;

	    case '\017':		/* extended character set - SI */
		    break;

	    case '\031':		/* next char from supplementary set */
		    break;

	    case '\033':		/* 2 or 3 byte escape sequence */
		    escape();
		    break;

	    default:
		    oput(ch);
		    break;
	}   /* End switch */

    formfeed();				/* next file starts on a new page? */

}   /* End of text */

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

inittabs()

{

    int		i;			/* loop index */

/*
 *
 * Initializes the horizontal and vertical tab arrays. The way tabs are handled is
 * quite inefficient and may not work for all initial hmi or vmi values.
 *
 */

    for ( i = 0; i < COLUMNS; i++ )
	htabstops[i] = ((i % 8) == 0) ? ON : OFF;

    for ( i = 0; i < ROWS; i++ )
	vtabstops[i] = ((i * ovmi) > BOTTOMMARGIN) ? ON : OFF;

}   /* End of inittabs */

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

cleartabs()

{