   Copyright (C) 1989, 1992 Aladdin Enterprises.  All rights reserved.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

This file, use.doc, describes how to use the Ghostscript language
interpreter.

For an overview of Ghostscript and a list of the documentation files, see
README.  

********
******** How to install Ghostscript ********
********

To run Ghostscript, you need the executable program, and also some
external initialization files:
	gs_*.ps (gs_dps1.ps, gs_fonts.ps, gs_init.ps, gs_lev2.ps,
		 gs_statd.ps, gs_dbt_e.ps, gs_sym_e.ps)
	uglyr.gsf
	Fontmap

The file name of the executable program depends on the environment;
see the instructions for the specific platforms below.

The Ghostscript fileset includes a set of fonts (.gsf files); you
should have them on line as well.

VMS
---

Installing Ghostscript on a VMS system requires compiling it first.
The name of the executable is GS.EXE.

You should install all the files, including the fonts, in the same
directory as the executable and initialization files.  By default,
this is the directory in which you did the compilation.  Consult the
command file (VMS-CC.MAK or VMS-GCC.MAK) for more details.

If you have DECWindows/Motif installed, you may wish to replace the
FONTMAP file with the file FONTMAP.VMS.  Read the comment at the
beginning of the latter file for more information.

MS-DOS
------

There are two MS-DOS executables in the standard Ghostscript
distribution:
	- GS.EXE runs on any MS-DOS machine, but is limited to 640K.
	- GS386.EXE runs on any 386 or 486 machine, and will use all
available extended (not expanded) memory.

You should install all the files except the fonts in C:\GS, and the
fonts in C:\GS\FONTS.

If you have Adobe Type Manager fonts installed on your system, and you
wish to use them with Ghostscript, you may wish to replace the FONTMAP
file with FONTMAP.ATM, and to add to the environment variable GS_LIB the
name of the directory where the fonts are located (see below for more
information about GS_LIB).  Before you do this, please read carefully the
license that accompanies the ATM fonts; Aladdin Enterprises takes no
responsibility for any possible violations of such licenses.

MS Windows
----------

The name of the executable is GSWIN.EXE.  Ghostscript requires Windows
3.1, and you must run Windows in 386 Enhanced or Standard (not Real) mode.
Since Ghostscript is a large program, you will need to run Windows in
Enhanced mode (so that it can provide virtual memory) unless you have at
least 6 Mb of RAM.

You should install all the files except the fonts in C:\GS, and the
fonts in C:\GS\FONTS.

See under "MS-DOS" above for information about using Adobe Type
Manager fonts with Ghostscript.

OS/2 2.0
--------

Ghostscript currently only runs in an OS/2 DOS Box.  Please read the
MS-DOS notes, since they apply to this environment as well.

If you run GS386 in the OS/2 2.0 DOS Box, you must select the
"ENABLED" setting for the DPMI_DOS_API option of the DOS Box.  GS386
will not run with the "AUTO" setting.

Unix
----

Installing Ghostscript on a Unix system requires compiling it first.
The name of the executable is gs.  The makefile installs all the
files, except the fonts, in /usr/local or various subdirectories
thereof.  The fonts should be installed in
/usr/local/lib/ghostscript/fonts.  Consult the makefile for more
details.

********
******** Shell scripts for Ghostscript
********

The Ghostscript distribution includes several Unix shell scripts for
driving Ghostscript in different environments.  These are all
user-contributed code: please contact the user identified in the file, not
Aladdin Enterprises, if you have questions.

> pv.sh - preview a specified page of a dvi file in an X window.

> sysvlp.sh - System V 3.2 lp interface for parallel printer.

> pj-gs.sh - printing on an H-P PaintJet under HP-UX.

> unix-lpr.sh - queue filter for lpr under Unix.
> lprsetup.sh - setup for unix-lpr.sh.

If one of these serves your needs, you may be able to skip most of
the rest of this document.

********
******** How to use the Ghostscript interpreter ********
********

To invoke the interpreter, give the command
	gs <filename1> ... <filenameN>
The interpreter will read in the files in sequence and execute them.
After doing this, it reads further input from the primary input stream
(normally the keyboard).  Each line (i.e. characters up to a <return>) is
interpreted separately.  To exit from the interpreter, type quit<return>.
The interpreter also exits gracefully if it encounters end-of-file.
Typing the interrupt character, e.g., control-C, is also safe.

The interpreter recognizes several switches described below, which may appear
anywhere in the command line and apply to all files thereafter.

You can get a help message by invoking Ghostscript with
	gs -h
or
	gs -?
This message also lists the available devices.  For a little more
information, a one-line description of each device appears near the
beginning of the file devs.mak.

Choosing the output device
--------------------------

Ghostscript may be built with multiple output devices.  Ghostscript
normally opens the first one and directs output to it.  To use device xyz
as the initial output device, include the switch
	-sDEVICE=xyz
in the command line.  Note that this switch must precede the first .ps
file, and only its first invocation has any effect.  For example, for
printer output in a normal configuration that includes an Epson printer
driver, you might use the shell command
	gs -sDEVICE=epson myfile.ps
instead of just
	gs myfile.ps
Alternatively, you can type
	(epson) selectdevice
	(myfile.ps) run
All output then goes to the printer instead of the display until further
notice.  You can switch devices at any time by using the selectdevice
procedure, e.g.,
	(vga) selectdevice
or
	(epson) selectdevice
As yet a third alternative, you can define an environment variable
GS_DEVICE as the desired default device name.  The order of precedence for
these alternatives, highest to lowest, is:
	selectdevice
	(command line)
	GS_DEVICE
	(first device in build list)

To select the density on a printer, use
	gs -sDEVICE=<device> -r<xres>x<yres>
For example, on a 9-pin Epson-compatible printer, you can get the
lowest-density (fastest) mode with
	gs -sDEVICE=epson -r60x72
and the highest-density mode with
	gs -sDEVICE=epson -r240x72.
On a 24-pin printer, the lowest density is
	gs -sDEVICE=epson -r60x60
and the highest-density 24-pin mode is
	gs -sDEVICE=epson -r360x180

If you select a printer as the output device, Ghostscript also allows you
to control where the device sends its output.  Normally, output goes
directly to the printer (PRN) on MS-DOS systems, and to a scratch file on
Unix or VMS systems.  To send the output to a series of files foo1.xyz,
foo2.xyz, ..., use the switch
	-sOutputFile=foo%d.xyz
(For compatibility with older versions of Ghostscript, -sOUTPUTFILE=
also works.)  The %d is a printf format specification; you can use
other formats like %02d.  Each file will receive one page of output.
Alternatively, to send the output to a single file foo.xyz, with all
the pages concatenated, use the switch
	-sOutputFile=foo.xyz

On Unix systems, you can send the output directly to a pipe.  For
example, to pipe the output to the command `lpr' (which, on many Unix
systems, is the command that spools output for a printer), use the
switch
	-sOutputFile=\|lpr
You can also send output to stdout for piping with the switch
	-sOutputFile=-
In this case you must also use the -q switch, to prevent Ghostscript from
writing messages to stdout.

To find out what devices are available, type
	devicenames ==
after starting up Ghostscript.  Alternatively you can use the -h or
-? switch in the command line, as described above.

Device configuration
--------------------

Ghostscript is normally configured to expect U.S. letter paper,
although there is a way to make A4 paper the default for certain
printers at compilation time (see devs.mak for details).  To select a
different paper size as the default, use the switch
	-sPAPERSIZE=a_known_paper_size
e.g.,
	-sPAPERSIZE=a4
or
	-sPAPERSIZE=legal
You can use any paper size listed in the table at the beginning of
gs_statd.ps.  (Individual documents can also specify a paper size,
which will take precedence over the one specified on the command
line.)

Printing on a Hewlett-Packard LaserJet at full resolution (300 DPI)
requires a printer with at least 1.5 Mb of memory.  150 DPI printing
requires only .5 Mb.  You can select 150 DPI printing with the command
line switch
	-r150
This is not necessary on DeskJet printers.

On MS-DOS systems using the Borland compiler, if Ghostscript gives
you a 'limitcheck in setdevice' error, it may mean Ghostscript's
standard buffer size wasn't large enough.  Likewise, if Ghostscript
gives you a 'VMerror in setdevice' error, it means the buffer size
was too large.  You can use the -dBufferSpace= switch to set the
buffer size to a different value, e.g.,
	-dBufferSpace=50000
The default value is 25000; the smallest value Ghostscript accepts is
10000; the largest valid value is 65000.

File searching
--------------

When looking for the initialization files (gs_*.ps), the files related to
fonts, or the file for the 'run' operator, Ghostscript first tries opening
the file with the name as given (i.e., using the current working directory
if none is specified).  If this fails, and the file name doesn't specify
an explicit directory or drive (i.e., doesn't begin with '/' on Unix
systems; doesn't contain a ':' or begin with a '/' or '\' on MS-DOS
systems; doesn't contain a ':' or a square bracket on VMS systems),
Ghostscript will try directories in the following order:

	- The directory/ies specified by the -I switch(es) in the command
	  line (see below), if any;

	- The directory/ies specified by the GS_LIB environment variable,
	  if any;

	- The directory/ies specified by the GS_LIB_DEFAULT macro in the
	  Ghostscript makefile, if any.

Each of these (GS_LIB_DEFAULT, GS_LIB, and -I parameter) may be either a
single directory, or a list of directories separated by a character
appropriate for the operating system (':' on Unix systems, ';' on VMS
systems, ';' on MS-DOS systems).

Temporary files
---------------

By default, Ghostscript creates temporary files named _temp_XX.XXX in the
current directory on MS-DOS and VMS systems, and named gs_XXXXX in the
/tmp directory on Unix systems.  You can change the directory in which
Ghostscript will create these files by setting the TEMP environment
variable to the name of the directory.

Ghostscript currently doesn't do a very good job of deleting temporary
files when it exits; you may have to delete them manually from time to
time.

********
******** Notes on specific platforms ********
********

VMS
---

On VMS systems, the last character of each "directory" name indicates what
sort of entity the "directory" references.  If the "directory" name ends
with a colon, it is taken as referring to a logical device, e.g.:
        $ DEFINE GHOSTSCRIPT_DEVICE DUA1:[GHOSTSCRIPT_14]
        $ DEFINE GS_LIB GHOSTSCRIPT_DEVICE:
If the "directory" name ends with a closing square bracket, it is taken as
referring to a real directory, e.g.:
        $ DEFINE GS_LIB DUA1:[GHOSTSCRIPT]

To run Ghostscript with switches, you must type a command like

	$ gs "-dNODISPLAY"

because the C run time library will convert the command
parameters/arguments to lowercase unless you enclose them in double quotes
which preserves the case.

If you are on an X Windows display (for which gs is built), you can do

	$ set display/create/node="domain-name"/transport=tcpip

For example,

	$ set display/create/node="doof.city.com"/transport=tcpip

and then run Ghostscript

	$ gs

If you write printer output to a file and then want to print the file
later, use the "/PASSALL" qualifier to the PRINT command.

MS-DOS
------

If you are running Ghostscript on a MS-DOS machine with a display
that is not EGA/VGA compatible, you must use the Borland compiler.
You must build Ghostscript with the BGI driver as the default, and
you will need the appropriate .BGI file from the Borland Turbo C
library.  (Ghostscript includes the EGA/VGA driver in the
executable.)

If you are using the BGI driver, two additional environment variables
become relevant:

	BGIPATH - defines the directory where Ghostscript will look for
the appropriate BGI driver.  If BGIPATH is not defined, Ghostscript will
look in the directory defined as BGIDIR in the makefile.  In either case,
if no driver is found in the designated directory, Ghostscript will look
in the current directory.

	BGIUSER - a string of the form nn.dname, where nn is a hexadecimal
number giving a display mode and dname is the name of a file containing a
user-supplied BGI driver.  If BGIUSER is defined and the BGI device is
selected, Ghostscript will supply nn as the display mode and will obtain
the driver from the file named dname.

Some applications, such as Microsoft Word, require a prologue in front of
the PostScript files they output.  In the case of Word, this is one of the
*.ini files included with the Word distribution.  Other applications may
require other prologues.  These may be specified on the Ghostscript
command line, e.g.,
	gs prologue.ini myfile.ps

X Windows
---------

Ghostscript looks for the following resources under the program name
"ghostscript" and class name "Ghostscript":

	Name			Class			Default
	----			-----			-------
	background		Background		white
	foreground		Foreground		black
	borderColor		BorderColor		black
	borderWidth		BorderWidth		1
	geometry		Geometry		NULL
	xResolution		Resolution		**
	yResolution		Resolution		**
	useExternalFonts	UseExternalFonts	true
	useScalableFonts	UseScalableFonts	true
	logExternalFonts	LogExternalFonts	false
	externalFontTolerance	ExternalFontTolerance	10.0
	palette			Palette			Color
	maxGrayRamp		MaxGrayRamp		128
	maxRGBRamp		MaxRGBRamp		5
	useBackingPixmap	UseBackingPixmap	true
	useXPutImage		UseXPutImage		true
	useXSetTile		UseXSetTile		true
	regularFonts		RegularFonts		see below
	symbolFonts		SymbolFonts		see below
	dingbatFonts		DingbatFonts		see below

** Calculated from display metrics.

    Notes on Resources:

	The geometry resource only affects window placement.

	Resolution is given in pixels per inch.

	The font tolerance gives largest acceptable difference in
	height of the screen font.  The tolerance is expressed as
	a percentage of the height of the desired font.

	The palette resource can be used to restrict ghostscript to
	using a grayscale or monochrome palette.

	The maxRGBRamp and maxGrayRamp control the maximum number of
	colors that ghostscript allocates ahead of time for the dither
	cube/ramp.  Ghostscript will never preallocate more than half
	of the cells in a colormap.

To use native X11 fonts, ghostscript must map PostScript font names to
the XLFD font names.  The regularFonts, symbolFonts, and dingbatFonts
resources give the name mapping for different encodings.  The XLFD font 
name in the mapping must contain seven dashes.  The X driver adds the
additional size and encoding fields to bring the total number of dashes
in the font name to 14.  Here are the default font mappings:

  Regular Fonts: (Fonts available in standard or ISO-Latin-1 encoding)

    AvantGarde-Book:-Adobe-ITC Avant Garde Gothic-Book-R-Normal--\n\
    AvantGarde-BookOblique:-Adobe-ITC Avant Garde Gothic-Book-O-Normal--\n\
    AvantGarde-Demi:-Adobe-ITC Avant Garde Gothic-Demi-R-Normal--\n\
    AvantGarde-DemiOblique:-Adobe-ITC Avant Garde Gothic-Demi-O-Normal--\n\
    Bookman-Demi:-Adobe-ITC Bookman-Demi-R-Normal--\n\
    Bookman-DemiItalic:-Adobe-ITC Bookman-Demi-I-Normal--\n\
    Bookman-Light:-Adobe-ITC Bookman-Light-R-Normal--\n\
    Bookman-LightItalic:-Adobe-ITC Bookman-Light-I-Normal--\n\
    Courier:-Adobe-Courier-Medium-R-Normal--\n\
    Courier-Bold:-Adobe-Courier-Bold-R-Normal--\n\
    Courier-BoldOblique:-Adobe-Courier-Bold-O-Normal--\n\
    Courier-Oblique:-Adobe-Courier-Medium-O-Normal--\n\
    Helvetica:-Adobe-Helvetica-Medium-R-Normal--\n\
    Helvetica-Bold:-Adobe-Helvetica-Bold-R-Normal--\n\
    Helvetica-BoldOblique:-Adobe-Helvetica-Bold-O-Normal--\n\
    Helvetica-Narrow:-Adobe-Helvetica-Medium-R-Narrow--\n\
    Helvetica-Narrow-Bold:-Adobe-Helvetica-Bold-R-Narrow--\n\
    Helvetica-Narrow-BoldOblique:-Adobe-Helvetica-Bold-O-Narrow--\n\
    Helvetica-Narrow-Oblique:-Adobe-Helvetica-Medium-O-Narrow--\n\
    Helvetica-Oblique:-Adobe-Helvetica-Medium-O-Normal--\n\
    NewCenturySchlbk-Bold:-Adobe-New Century Schoolbook-Bold-R-Normal--\n\
    NewCenturySchlbk-BoldItalic:-Adobe-New Century Schoolbook-Bold-I-Normal--\n\
    NewCenturySchlbk-Italic:-Adobe-New Century Schoolbook-Medium-I-Normal--\n\
    NewCenturySchlbk-Roman:-Adobe-New Century Schoolbook-Medium-R-Normal--\n\
    Palatino-Bold:-Adobe-Palatino-Bold-R-Normal--\n\
    Palatino-BoldItalic:-Adobe-Palatino-Bold-I-Normal--\n\
    Palatino-Italic:-Adobe-Palatino-Medium-I-Normal--\n\
    Palatino-Roman:-Adobe-Palatino-Medium-R-Normal--\n\
    Times-Bold:-Adobe-Times-Bold-R-Normal--\n\
    Times-BoldItalic:-Adobe-Times-Bold-I-Normal--\n\
    Times-Italic:-Adobe-Times-Medium-I-Normal--\n\
    Times-Roman:-Adobe-Times-Medium-R-Normal--\n\
    ZapfChancery-MediumItalic:-Adobe-ITC Zapf Chancery-Medium-I-Normal--

  Symbol Fonts:  (using Symbol encoding)

    Symbol: -Adobe-Symbol-Medium-R-Normal--

  Dingbat Fonts: (using Dingbat encoding)

    ZapfDingbats: -Adobe-ITC Zapf Dingbats-Medium-R-Normal--

To set these resources, put them in a file (such as ~/.Xdefaults) in the
following form:

Ghostscript*geometry:	-0+0
Ghostscript*xResolution: 72
Ghostscript*yResolution: 72

Then load the defaults into the X server:

% xrdb -merge ~/.Xdefaults

On H-P systems, Ghostscript will take advantage of the "HP XLFD
Enhancements" to use native X11 fonts for fonts that are anamorphically
scaled, rotated, or mirrored.  If the user has installed these changes to
their X or font server, they will automatically be used when appropriate.

Normal switches
---------------

	@filename
		Causes Ghostscript to read filename and treat its
		contents the same as the command line.  (This is
		intended primarily for getting around DOS'
		128-character limit on the length of a command line.)
		Switches or file names in the file may be separated by
		any amount of white space (space, tab, line break);
		there is no limit on the size of the file.

	-- filename arg1 ...
		Takes the next argument as a file name as usual, but takes
		all remaining arguments (even if they have the syntactic
		form of switches) and defines the name ARGUMENTS in
		userdict (not systemdict) as an array of those strings,
		*before* running the file.  When Ghostscript finishes
		executing the file, it exits back to the shell.

	-Dname=token
	-dname=token
		Define a name in systemdict with the given definition.
		The token must be exactly one token (as defined by the
		'token' operator) and must not contain any whitespace.

	-Dname
	-dname
		Define a name in systemdict with value=null.

	-Sname=string
	-sname=string
		Define a name in systemdict with a given string as value.
		This is different from -d.  For example,
			-dname=35
		is equivalent to the program fragment
			/name 35 def
		whereas
			-sname=35
		is equivalent to
			/name (35) def

	-q
		Quiet startup -- suppress normal startup messages,
		and also do the equivalent of -dQUIET.

	-ffilename
		Executes the given file, even if its name begins with a -.

	-gnumber1xnumber2
		Equivalent to -dDEVICEWIDTH=number1 and
		-dDEVICEHEIGHT=number2.  This is for the benefit of
		devices (such as X11 windows and VESA displays) that require
		(or allow) width and height to be specified.

	-rnumber
	-rnumber1xnumber2
		Equivalent to -dDEVICEXRESOLUTION=number1 and
		-dDEVICEYRESOLUTION=number2.  This is for the benefit of
		devices (such as printers) that support multiple
		X and Y resolutions.

	-Idirectories
		Adds the designated list of directories at the head of the
		search path for library files.

	-
		This is not really a switch.  It indicates to Ghostscript
		that the standard input is coming from a file or a pipe.
		Ghostscript reads from stdin until reaching end-of-file,
		executing it like any other file, and then continues
		processing the command line.  At the end of the command
		line, Ghostscript exits rather than going into its
		interactive mode.

Note that gs_init.ps makes systemdict read-only, so the values of names
defined with -D/d/S/s cannot be changed (although, of course, they can be
superseded by definitions in userdict or other dictionaries.)

Special names
-------------

-dDISKFONTS
	causes individual character outlines to be loaded from the disk
the first time they are encountered.  (Normally Ghostscript loads all the
character outlines when it loads a font.)  This may allow loading more
fonts into RAM, at the expense of slower rendering.

-dNOBIND
	disables the 'bind' operator.  Only useful for debugging.

-dNOCACHE
	disables character caching.  Only useful for debugging.

-dNODISPLAY
	suppresses the normal initialization of the output device.  This
may be useful when debugging.

-dNOPAUSE
	disables the prompt and pause at the end of each page.  This may
be desirable for applications where another program is 'driving'
Ghostscript.

-dNOPLATFONTS
	disables the use of fonts supplied by the underlying platform
(X Windows or Microsoft Windows).  This may be needed if the platform
fonts look undesirably different from the scalable fonts.

-dSAFER
	disables the deletefile and renamefile operators, and the
ability to open files in any mode other than read-only.  This may be
desirable for spoolers or other sensitive environments.

-dWRITESYSTEMDICT
	leaves systemdict writable.  This is necessary when running
special utility programs such as font2c and pcharstr, which must bypass
normal PostScript access protection.

-sDEVICE=device
	selects an alternate initial output device, as described above.

-sOutputFile=filename
	selects an alternate output file (or pipe) for the initial output
device, as described above.

Debugging switches
------------------

The -Z switch only applies if the interpreter was built for a
debugging configuration (DEBUG=1 or -DDEBUG selected at compile
time).

	-A	Turn on allocator debugging (gs_malloc and gs_free).

	-e	Turn on tracing of error returns from operators.

	-E	Abort when any operator returns with an error.

	-Mn	Force the interpreter's allocator to acquire additional
		memory in units of nK, rather than the default (currently
		20K on MS-DOS systems, 50K on Unix).  n is a positive
		decimal integer (not exceeding 63 on MS-DOS systems).

	-Zxxx	Turn on debugging printout.
		Each of the xxx characters selects an option:
		if the string is empty, all options are selected.
		Case is significant.
			1 = type 1 font interpreter (type1addpath)
			2 = curve subdivider/rasterizer
			a = allocator (large blocks only)
			  A = allocator (all calls)
			b = bitmap image processor
			  B = bitmap images, detail
			c = color/halftone mapper
			d = dictionary put/undef
			f = fill algorithm (summary)
			  F = fill algorithm (detail)
			g = gsave/grestore[all]
			h = halftone renderer
			i = interpreter, just names
			  I = interpreter, everything
			k = character cache & xfonts
			  K = character cache, every access
			l = command lists, bands
			  L = command lists, everything
			m = makefont and font cache
			n = name lookup (new names only)
			o = outliner (stroke)
			p = path tracer
			q = clipping
			r = arc renderer
			s = scanner
			t = tiling algorithm
			u = undo saver (for save/restore)
			  U = undo saver, more detail
			v = rectangle fill
			  V = device-level output
			w = compression encoder/decoder
			x = transformations
			y = Type 1 hints
			  Y = Type 1 hints, every access
			z = trapezoid fill
