path: root/gs/use.txt

   Copyright (C) 1989, 1995, 1996, 1997 Aladdin Enterprises.  All rights reserved.
  
  This file is part of Aladdin Ghostscript.
  
  Aladdin Ghostscript is distributed with NO WARRANTY OF ANY KIND.  No author
  or distributor accepts any responsibility for the consequences of using it,
  or for whether it serves any particular purpose or works at all, unless he
  or she says so in writing.  Refer to the Aladdin Ghostscript Free Public
  License (the "License") for full details.
  
  Every copy of Aladdin Ghostscript must include a copy of the License,
  normally in a plain ASCII text file named PUBLIC.  The License grants you
  the right to copy, modify and redistribute Aladdin Ghostscript, but only
  under certain conditions described in the License.  Among other things, the
  License requires that the copyright notice and this notice be preserved on
  all copies.

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

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

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

********
******** Installing Ghostscript
********

Please read the documentation file install.txt for information on installing
Ghostscript.

********
******** Unix 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 Ghostscript ********
********

The command (that is, a shell command in environments other than MS Windows,
or a 'Run' line in MS Windows) to invoke Ghostscript is:
	gs <filename1> ... <filenameN>
Normally the files are PostScript or EPS files, but depending on how
Ghostscript was built, they may also be PDF files or MS-DOS EPSF files.  The
interpreter will read in the files in sequence (using the method described
under "File searching" below to find the files) and execute them.  After
doing this, it reads further input from the primary input stream (normally
the keyboard), consisting of PostScript language commands.  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 many switches described below, which may appear
anywhere in the command line and apply to all files thereafter.

Many of the switches include an '=' followed by a parameter.  Because of a
strange design decision in the Watcom C/C++ run-time library, you must use
'#' rather than '=' with Ghostscript if Ghostscript was compiled with Watcom
C/C++.  In particular, the MS-DOS executable included in the standard
Ghostscript distribution (gs386.exe) was compiled this way.

You can get a brief help message by invoking Ghostscript with
	gs -h
or
	gs -?
This message also lists the available devices.  For a little more
information about available devices, 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, once you are inside Ghostscript, 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 resolution on a printer, use the shell command
	gs -sDEVICE=<device> -r<xres>x<yres>
For example, on a 9-pin Epson-compatible printer, you can get the
lowest-resolution (fastest) mode with
	gs -sDEVICE=epson -r60x72
and the highest-resolution mode with
	gs -sDEVICE=epson -r240x72.
On a 24-pin printer, the lowest resolution is
	gs -sDEVICE=epson -r60x60
and the highest-resolution 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.

File formats like PCX and PBM are also 'devices'.  When you select a file
format as the 'device', you must also specify an output file, e.g.,
	gs -sDEVICE=pcxmono -sOutputFile=xyz.pcx

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.

Choosing paper size
-------------------

Ghostscript is normally configured to use U.S. letter paper as the default.
To select a different default paper size, find the line in gs_init.ps that
says

	% Optionally choose a default paper size other than U.S. letter.

The next line begins

	% (a4)

To select A4 as the default paper size, remove the % but do not change
anything else.  To select a different default paper size, remove the % and
replace the word a4 with the name of the desired paper size.  You can use
any paper size listed in the table at the beginning of gs_statd.ps.

Alternatively, to select a different default paper size for a single
invocation of Ghostscript, you can use the command line switch
	-sPAPERSIZE=a_known_paper_size
e.g.,
	-sPAPERSIZE=a4
or
	-sPAPERSIZE=legal

Individual documents also can (and often do) specify a paper size, which
will take precedence over the default one.  If you want to force a specific
paper size, ignoring the paper size specified in the document, make that
paper size the default (as just described), and also include
	-dFIXEDMEDIA
on the command line.

Finally, most (but not all) of Ghostscript's printer drivers can be
configured at compile time to use A4 paper as the default by including
-DA4 in the CFLAGS switches in the makefile.  See make.txt for more
details.

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

When looking for initialization files (gs_*.ps, pdf_*.ps), font files, the
Fontmap file, and files named on the command line, Ghostscript first tests
whether the file name specifies an explicit directory.  The test is as
follows:

	- On Unix systems, Ghostscript tests whether the name begins with
	'/', or with one or more '.'s followed by a '/'.

	- On MS-DOS or MS Windows systems, Ghostscript tests whether the
	name has a ':' as its second character, or begins with '/' or
	'\', or with one or more '.'s followed by a '/' or '\'.

	- On VMS systems, Ghostscript tests whether the name contains a
	node, device, root, or directory specification.

If the file name does specify an explicit directory (the test succeeds),
Ghostscript simply tries to open the file using the given name.  Otherwise,
Ghostscript will try directories in the following order:

	- The current directory (unless disabled by the -P- switch);

	- 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).  We think that trying the current directory
first is a very bad idea -- it opens serious security loopholes and can lead
to very confusing errors if one has more than one version of Ghostscript in
one's environment -- but when we attempted to change it, users insisted that
we change it back.  You can disable looking in the current directory first
using the -P- switch described below.

Note that Ghostscript does not use this file searching algorithm for the
'run' or 'file' operators: for these operators, it simply opens the file
with the given name.  To run a file using the searching algorithm, use
'runlibfile' instead of 'run'.

Resources
---------

Ghostscript uses a completely different rule for looking for files
containing PostScript Level 2 "resources": per the Adobe documentation, it
concatenates together:

	- The value of the system parameter GenericResourceDir
	(initially "/Resource/");

	- The name of the resource category (e.g., ProcSet);

	- The value of the system parameter GenericResourcePathSep
	(initially "/");

	- The name of the resource instance (e.g., CIDInit).

For looking up fonts, after exhausting the search method described in the
next section, it concatenates together:

	- The value of the system parameter FontResourceDir
	(initially "/Resource/Font/");

	- The name of the resource font (e.g., Times-Roman).

Note that even though the system parameters are named somethingDir, they are
not just plain directory names: they have a "/" on the end, so that they can
be concatenated with the category name or font name.

Font lookup
-----------

Ghostscript has a slightly different rule for determining how to find the
file containing a font with a given name.  This rule uses not only the
search path defined by -I, GS_LIB, and GS_LIB_DEFAULT as described above,
but an additional list of directories which is the value of the GS_FONTPATH
environment variable (or the value provided with the -sFONTPATH= switch, if
present).

When Ghostscript needs to find a font that isn't already loaded into memory,
it starts by looking for Fontmap files in every directory on the search
path: these files provide mappings between font names and file names.  (See
the Fontmap file in the Ghostscript distribution for details.)  If it can't
find a font in any Fontmap file in the search path (or in the list provided
with the -sFONTMAP= switch, if present), it looks at the GS_FONTPATH
environment variable (or the value provided with the -sFONTPATH= switch, if
present), which is also a list of directories.  It goes to those
directories, one by one, and looks for all files that appear to contain
PostScript fonts; it then effectively adds all those files and fonts to its
internal copy of the Fontmap (the catalog of fonts and the files that
contain them).

To summarize, the differences between the search path (-I, GS_LIB,
GS_LIB_DEFAULT) and the font path (-sFONTPATH=, GS_FONTPATH) are:

    Search path:

	- Consulted first.

	- Font name -> file name mapping given in Fontmap files;
	aliases are possible, and there need not be any relation
	between the font name in the Fontmap and the FontName in
	the file.

	- Only fonts and files named in Fontmap are used.

    Font path:

	- Consulted only if search path doesn't provide the file.

	- Font name -> file name mapping is implicit -- the
	FontName in the file is used.  Aliases are not possible.

	- Every Type 1 font file in each directory is available.

If you are using one of the following types of computer, you
may wish to set GS_FONTPATH to the indicated value so that Ghostscript will
automatically acquire all the installed Type 1 fonts:

	System type		GS_FONTPATH
	-----------		-----------
	DEC OSF/1		/usr/lib/X11/fonts/Type1Adobe
	DEC Ultrix		/usr/lib/DPS/outline/decwin
	HP-UX 9			/usr/lib/X11/fonts/type1.st/typefaces
	IBM AIX			/usr/lpp/DPS/fonts/outlines
	  "			/usr/lpp/X11/lib/X11/fonts/Type1
	  "			/usr/lpp/X11/lib/X11/fonts/Type1/DPS
	NeXT			/NextLibrary/Fonts/outline
	SGI IRIX		/usr/lib/DPS/outline/base
	  "			/usr/lib/X11/fonts/Type1
	Sun SunOS 4.x		/usr/openwin/lib/X11/fonts/Type1/outline
	  " (NeWSprint only)
   newsprint_2.5/SUNWsteNP/reloc/$BASEDIR/NeWSprint/small_openwin/lib/fonts
	Sun Solaris 2		/usr/openwin/lib/X11/fonts/Type1/outline
	VMS			SYS$COMMON:[SYSFONT.XDPS.OUTLINE]

These paths may not be exactly right for your installation; if the
indicated directory doesn't contain files whose names are familiar font
names like Courier and Helvetica, you may wish to ask your system
administrator where to find these fonts.

Adobe Acrobat comes with a set of 14 Type 1 fonts, typically in a directory
called some_path_name_or_other/Acrobat3/Fonts.  There is no particular
reason to use these instead of the corresponding fonts in the Ghostscript
distribution, aside from saving about 1 Mb of disk space, but if you want to
do this, see install.txt.

NOTE: On Solaris systems simply setting GS_FONTPATH may not work, because
for some reason some versions of Ghostscript can't seem to find any of the
Type1 fonts in /usr/openwin/lib/X11/fonts/Type1/outline.  It says: "15
files, 15 scanned, 0 new fonts".  See Fontmap.Sol instead.

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

By default, Ghostscript creates temporary files named _temp_XX.XXX in the
current directory on MS-DOS and VMS systems, gsXXXXXX in the current
directory on OS/2 systems, and 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.

Environment variable summary
----------------------------

GS_DEVICE
	Defines the default output device.  Described above.

GS_FONTPATH
	Specifies a list of directories that should be scanned for fonts if
a requested font can't be found anywhere on the search path.  Described
above.

GS_LIB
	Provides a search path for initialization files and fonts.
Described above.

GS_OPTIONS
	Defines a list of command line arguments to be processed before
the ones actually specified on the command line.  For example, setting
GS_DEVICE to xxx is equivalent to setting GS_OPTIONS to -sDEVICE=xxx.  The
contents of GS_OPTIONS are not limited to switches; they may include
actual file names or even @file arguments.

TEMP
	Defines a directory name for temporary files.  Described above.

********
******** Using Ghostscript and Ghostview with PDF files
********

Ghostscript is normally configured (except on 16-bit MS-DOS platforms) so
that it can interpret both PostScript and PDF files (the latter are
sometimes incorrectly called "Acrobat files").  It examines each file to
determine automatically whether it is a PDF file or a PostScript file.  All
the normal switches and procedures for interpreting PostScript files also
apply to PDF files, with a few exceptions noted below.  In addition, there
is a shell script / batch file

		pdf2ps input.pdf output.ps

that converts PDF to (Level 2) PostScript.

Switches not applicable to PDF files
------------------------------------

You cannot use the `-' switch to provide PDF input from stdin or a pipe.
The PDF language, unlike the PostScript language, inherently requires random
access to the file.

Added switches for PDF files
----------------------------

	-dFirstPage=pagenumber
		Starts interpreting on the given page of the document.

	-dLastPage=pagenumber
		Stops interpreting after the given page of the document.

	-sPSFile=filename
		Writes the PostScript equivalent of the PDF input on the
		given file.

Ghostview and PDF files
-----------------------

Since Ghostview pipes PostScript files to Ghostscript, you cannot view PDF
files with Ghostview just by saying
		ghostview file.pdf
Instead there are two options:

   1. Tanmoy Bhattacharya has written some patches for Ghostview 1.5
   that allow it to read and display PDF files.  These are available
   from:
       ftp://gita.lanl.gov/people/tanmoy/hypertex/gv1.5gs3.33hack.tar.gz

   2. Start Ghostview as follows:
          ghostview -arguments file.pdf quit.ps
   This will allow you to display a PDF file, but you won't be able
   to jump to particular pages.  Use Tanmoy's code if you want that
   facility.

********
******** 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]

In order to specify switches and file names when invoking the interpreter,
define GS as a foreign command:
	$ GS == "$disk:[directory]GS.EXE"
where "disk" and "directory" specify the disk and directory where Ghostscript
is located.  For instance,
	$ GS == "$DUA1:[GHOSTSCRIPT]GS.EXE"
To allow the interpreter to be run from any directory, define the logical
GS_LIB which points to the Ghostscript directory
	$ DEFINE GS_LIB disk:[directory]
This allows Ghostscript to locate its initialization files stored in the
Ghostscript directory -- see use.txt for further details.  Finally, to
invoke the interpreter, merely type GS.  Although DCL normally converts
unquoted parameters to upper case, C programs receive their parameters in
lower case.  That is, the command
	$ GS -Isys$login:
passes the switch "-isys$login" to the interpreter.  To preserve the
case of switches, enclose them in double quotes; e.g.,
	$ GS "-Isys$login:"

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.

In order to get PDF files (or PostScript files that use the setfileposition
operator) to work properly on VMS systems, you must ensure that they are
"stream LF" type files.  (**NOTE**: This only applies if you are using DEC C
to compile Ghostscript; there is no known way to get these files to work
properly with the old VAX C compiler.)  If you transfer files by FTP, you
probably need to do one of the following two things after the transfer:

1. If FTP'd in text/ASCII mode then do:

     $ CONVERT/FDL=STREAMLF.FDL input-file output-file

   where the contents of the file STREAMLF.FDL are given below.

2. Otherwise, if FTP'd in binary mode do

     $ SET FILE/ATTRIBUTE=(RFM:STMLF)

The contents of the STREAMLF.FDL file are shown between, and exclusive of, the
dashed lines:

-------------------------------------------------
FILE
        ORGANIZATION            sequential

RECORD
        BLOCK_SPAN              yes
        CARRIAGE_CONTROL        carriage_return
        FORMAT                  stream_lf
-------------------------------------------------

MS-DOS
------

Ghostscript supports many SuperVGA displays directly, most of them with
more than 16 colors.  The complete list is in the file devs.mak, which is
part of the Ghostscript source code.  (If you got Ghostscript under the
Aladdin Ghostscript Free Public License, the person or place from which you
got it is also required to make the source code available to you; if you
got it under the GNU License, see the GNU License for more information.)

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

If you have a SuperVGA display that supports a 16-color mode with 800x600
pixels, and you know the display mode number for this mode, you can select
it by using the command line switches
	-sDEVICE=svga16 -dDisplayMode=NNN
where NNN is the display mode number in decimal.  The modes for some
popular display chipsets are as follows:

    Acumos AVGA2, AVGA3                         88	(0x58)
    Advance Logic AL2101                        43	(0x2B)
    Ahead V5000                                 113	(0x71)
    ATI VGAWONDER, Graphics Ultra etc.          84	(0x54)
    Chips and Technologies                      106	(0x6A)
    Cirrus Logic CL-GD 500/600                  100	(0x64)
    Cirrus Logic GD 5422                        88	(0x58)
    Compaq VGA                                  89	(0x59)
    CTI                                         106	(0x6A)
  * Genoa 5xxx, Sigma VGA                       41	(0x29)
    Genoa 6xxx                                  106	(0x6A)
    MXIC MX 68010                               85	(0x55)
    NCR 77C22                                   88	(0x58)
    OAK Technologies OTI-067, OTI-077, OTI037C  82	(0x52)
    OAK Technologies OTI037C w/ NEL BIOS        91	(0x5B)
  * Orchid Prodesigner                          41	(0x29)
    Paradise                                    88	(0x58)
    Poach                                       106	(0x6A)
    Primus                                      42	(0x2A)
    Realtek RT 3106                             31	(0x1F)
    Tecmar                                      22	(0x16)
    Trident 8900                                91	(0x5B)
  * Tseng ET-3000, ET-4000                      41	(0x29)
  * VEGA                                        41	(0x29)
    Video 7 SVGA                                98	(0x62)
    WD90C11                                     92	(0x5C)
    Western Digital                             88	(0x58)

The ones marked * are the default (they all use the same value.)  If your
card's chipset doesn't appear on this list, or if you try the value here
and it doesn't work, please e-mail the chipset and correct display mode to
ghost@aladdin.com for inclusion in future releases.

NOTE: The remainder of the MS-DOS section is currently not relevant, because
the Borland compilers do not support 32-bit MS-DOS executables, and
Ghostscript no longer supports the 16-bit MS-DOS environment.  We have
retained this section on the off-chance that Borland will support 32-bit
MS-DOS compilation at some future time.

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.

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
        maxDynamicColors	MaxDynamicColors	256
	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:

	Ghostscript doesn't look at the default system background and
	foreground colors; if you want to change the background or
	foreground color, you must set them explicitly for Ghostscript.
	(This is a deliberate choice, so that PostScript documents will
	display correctly -- with white = white and black = black --
	by default, even if text windows use other colors.)

	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.  maxDynamicColors controls the
	maximum number of colors that Ghostscript will allocate
	dynamically in the colormap.

The use... resources exist primarily to work around bugs in X servers.  In
particular, many versions of DEC's X server (DECwindows) have bugs that
require setting useXPutImage or useXSetTile to false.

	Some servers do not implement backing pixmaps properly, or do not
	have enough memory for them.  If you get strange behavior or "out
	of memory" messages, try setting useBackingPixmap to false.

	Some servers do not implement tiling properly.  This will show up
	as broad bands of color where dither patterns should appear.  If
	this happens, try setting useXSetTile to false.

	Some servers do not implement bitmap/pixmap displaying properly.
	This may show up as white or black rectangles where characters
	should appear, or characters may appear in "inverse video" (e.g.,
	white on a black rectangle).  If this happens, try setting
	useXPutImage to false.

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--

For X11/NeWS, one can use the OpenWindows scalable fonts instead, which
will give good quality output for any point size.  In this environment,
the relevant section of the resource file should look like this:

Ghostscript.regularFonts: \
	AvantGarde-Book:		-itc-avantgarde-book-r-normal-- \n\
	AvantGarde-BookOblique:		-itc-avantgarde-book-o-normal-- \n\
	AvantGarde-Demi:		-itc-avantgarde-demi-r-normal-- \n\
	AvantGarde-DemiOblique:		-itc-avantgarde-demi-o-normal-- \n\
	Bembo:				-monotype-bembo-medium-r-normal-- \n\
	Bembo-Bold:			-monotype-bembo-bold-r-normal-- \n\
	Bembo-BoldItalic:		-monotype-bembo-bold-i-normal-- \n\
	Bembo-Italic:			-monotype-bembo-medium-i-normal-- \n\
	Bookman-Demi:			-itc-bookman-demi-r-normal-- \n\
	Bookman-DemiItalic:		-itc-bookman-demi-i-normal-- \n\
	Bookman-Light:			-itc-bookman-light-r-normal-- \n\
	Bookman-LightItalic:		-itc-bookman-light-i-normal-- \n\
	Courier:			-itc-courier-medium-r-normal-- \n\
	Courier-Bold:			-itc-courier-bold-r-normal-- \n\
	Courier-BoldOblique:		-itc-courier-bold-o-normal-- \n\
	Courier-Oblique:		-itc-courier-medium-o-normal-- \n\
	GillSans:			-monotype-gill-medium-r-normal-sans- \n\
	GillSans-Bold:			-monotype-gill-bold-r-normal-sans- \n\
	GillSans-BoldItalic:		-monotype-gill-bold-i-normal-sans- \n\
	GillSans-Italic:		-monotype-gill-normal-i-normal-sans- \n\
	Helvetica:			-linotype-helvetica-medium-r-normal-- \n\
	Helvetica-Bold:			-linotype-helvetica-bold-r-normal-- \n\
	Helvetica-BoldOblique:		-linotype-helvetica-bold-o-normal-- \n\
	Helvetica-Narrow:		-linotype-helvetica-medium-r-narrow-- \n\
	Helvetica-Narrow-Bold:		-linotype-helvetica-bold-r-narrow-- \n\
	Helvetica-Narrow-BoldOblique:	-linotype-helvetica-bold-o-narrow-- \n\
	Helvetica-Narrow-Oblique:	-linotype-helvetica-medium-o-narrow-- \n\
	Helvetica-Oblique:		-linotype-helvetica-medium-o-normal-- \n\
	LucidaBright:			-b&h-lucidabright-medium-r-normal-- \n\
	LucidaBright-Demi:		-b&h-lucidabright-demibold-r-normal-- \n\
	LucidaBright-DemiItalic:	-b&h-lucidabright-demibold-i-normal-- \n\
	LucidaBright-Italic:		-b&h-lucidabright-medium-i-normal-- \n\
	LucidaSans:			-b&h-lucida-medium-r-normal-sans- \n\
	LucidaSans-Bold:		-b&h-lucida-bold-r-normal-sans- \n\
	LucidaSans-BoldItalic:		-b&h-lucida-bold-i-normal-sans- \n\
	LucidaSans-Italic:		-b&h-lucida-medium-i-normal-sans- \n\
	LucidaSans-Typewriter:		-b&h-lucidatypewriter-medium-r-normal-sans- \n\
	LucidaSans-TypewriterBold:	-b&h-lucidatypewriter-bold-r-normal-sans- \n\
	NewCenturySchlbk-BoldItalic:	-linotype-new century schoolbook-bold-i-normal-- \n\
	NewCenturySchlbk-Bold:		-linotype-new century schoolbook-bold-r-normal-- \n\
	NewCenturySchlbk-Italic:	-linotype-new century schoolbook-medium-i-normal-- \n\
	NewCenturySchlbk-Roman:		-linotype-new century schoolbook-medium-r-normal-- \n\
	Palatino-Bold:			-linotype-palatino-bold-r-normal-- \n\
	Palatino-BoldItalic:		-linotype-palatino-bold-i-normal-- \n\
	Palatino-Italic:		-linotype-palatino-medium-i-normal-- \n\
	Palatino-Roman:			-linotype-palatino-medium-r-normal-- \n\
	Rockwell:			-monotype-rockwell-medium-r-normal-- \n\
	Rockwell-Bold:			-monotype-rockwell-bold-r-normal-- \n\
	Rockwell-BoldItalic:		-monotype-rockwell-bold-i-normal-- \n\
	Rockwell-Italic:		-monotype-rockwell-medium-i-normal-- \n\
	Times-Bold:			-linotype-times-bold-r-normal-- \n\
	Times-BoldItalic:		-linotype-times-bold-i-normal-- \n\
	Times-Italic:			-linotype-times-medium-i-normal-- \n\
	Times-Roman:			-linotype-times-medium-r-normal-- \n\
	Utopia-Bold:			-adobe-utopia-bold-r-normal-- \n\
	Utopia-BoldItalic:		-adobe-utopia-bold-i-normal-- \n\
	Utopia-Italic:			-adobe-utopia-regular-i-normal-- \n\
	Utopia-Regular:			-adobe-utopia-regular-r-normal-- \n\
	ZapfChancery-MediumItalic:	-itc-zapfchancery-medium-i-normal-- \n
Ghostscript.dingbatFonts: \
	ZapfDingbats:			-itc-zapfdingbats-medium-r-normal--
Ghostscript.symbolFonts: \
	Symbol:				--symbol-medium-r-normal--

Users who switch regularly between different X servers may wish to use the
'*' wild card in place of the foundry name (itc, monotype, linotype, b&h,
or adobe); users who do not switch X servers should leave the explicit
foundry in the name, since it speeds up font accessing.

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

Ghostscript will take advantage of the "HP XLFD Enhancements," if
available, 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.

SCO Unix
--------

Because of bugs in the SCO Unix kernel, Ghostscript will not work if you
select direct screen output (gdevsco.c) and also allow it to write messages
on the console.  If you are using direct screen output, redirect
Ghostscript's terminal output to a file.

********
******** Switches
********

Unless otherwise noted, these apply to all platforms.

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

    Input control
    -------------

	@filename
		Causes Ghostscript to read filename and treat its
		contents the same as the command line.  (This is
		intended primarily for getting around MS-DOS's
		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 ...
	-+ 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.

	-@ filename arg1 ...
		Does the same thing as -- and -+, but expands @filename
		arguments.

	-
		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: this switch works only for
		PostScript, not for PDF.

	-c tokens ...
		Interprets arguments, up to the next argument that begins
		with - followed by a non-digit or with @, as PostScript
		code.  For example, if the file quit.ps contains just
		the word `quit', the following are equivalent:
			quit.ps
		and
			-c quit
		Each argument must be exactly one token, as defined by
		the `token' operator.

	-ffilename
		Execute the given file, even if its name begins with a -
		or an @.  -f alone does nothing, but it provides a
		convenient way to terminate the list of tokens for the -c
		switch.

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

	Note that by "library files" we mean all the files identified as
	using the search rule under "File searching" above: Ghostscript's
	own initialization files, fonts, and files named on the command
	line.

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

	-P
		Makes Ghostscript look first in the current directory for
		library files.  This is currently the default.
	-P-
		Makes Ghostscript *not* look first in the current directory
		for library files (unless, of course, the first explicitly
		supplied directory is `.').

    Parameter setting
    -----------------

	-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.
		If the token is a non-literal name, it must be true,
		false, or null.

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

	-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

	-uname
		Un-define a name, cancelling -d or -s.

	-gnumber1xnumber2
		Equivalent to -dDEVICEWIDTH=number1 and
		-dDEVICEHEIGHT=number2, specifying the device width and
		height in pixels.  This is for the benefit of devices (such
		as X11 windows and VESA displays) that require (or allow)
		width and height to be specified.  Note that this causes
		documents of other sizes to be clipped, not scaled:
		see -dFIXEDMEDIA below.

	-rnumber
	-rnumber1xnumber2
		Equivalent to -dDEVICEXRESOLUTION=number1 and
		-dDEVICEYRESOLUTION=number2, specifying the device
		horizontal and vertical resolution in pixels per inch.  This
		is for the benefit of devices (such as printers) that
		support multiple X and Y resolutions.

    Miscellaneous
    -------------

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

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

-dBATCH
	causes Ghostscript to exit after processing all files named on the
command line, rather than going into an interactive loop reading PostScript
commands.  Equivalent to putting -c quit at the end of the command line.

-dCOLORSCREEN
-dCOLORSCREEN=0
-dCOLORSCREEN=false
	On high-resolution devices (at least 150 dpi resolution, or
-dDITHERPPI specified), -dCOLORSCREEN forces the use of separate halftone
screens with different angles for C/M/Y/K or R/G/B if halftones are needed
(this produces the best-quality output); -dCOLORSCREEN=0 uses separate
screens with the same frequency and angle; -dCOLORSCREEN=false forces the
use of a single binary screen.  If COLORSCREEN is not specified, the default
is to use separate screens with different angles if the device has fewer
than 5 bits per color, and a single binary screen (which will never actually
be used under normal circumstances) on all other devices.

-dDELAYBIND
	causes 'bind' to remember all its invocations, but not actually
execute them until the .bindnow procedure is called.  Useful only for
certain specialized packages like pstotext that redefine operators.

-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.  DISKFONTS is only
effective if the diskfont feature was selected in the executable; otherwise
it is ignored.

-dDITHERPPI=lpi
	forces all devices to be considered high-resolution, and forces use
of a halftone screen or screens with lpi lines per inch, disregarding the
actual device resolution.  Reasonable values for lpi are N/5 to N/20, where
N is the resolution in dots per inch.

-dFIXEDMEDIA
	causes the media size to be fixed after initialization, and causes
pages of other sizes or orientations to be clipped.  This may be useful when
printing documents on a printer that can handle their requested paper size
but whose default is some other size.  Note that -g automatically sets
-dFIXEDMEDIA, but -sPAPERSIZE= does not.

-dFIXEDRESOLUTION
	causes the media resolution to be fixed similarly.  -r automatically
sets -dFIXEDRESOLUTION.

-dLOCALFONTS
	causes Type 1 fonts to be loaded into the current VM, which is
normally local VM, instead of always being loaded into global VM.  Only
useful for compatibility with Adobe printers for loading some obsolete
fonts.

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

-dNOCACHE
	disables character caching.  Only useful for debugging.

-dNOCIE
	substitutes DeviceGray and DeviceRGB for CIEBasedA and CIEBasedABC
color spaces respectively.  Only useful on very slow systems where color
accuracy is less important.

-dNODISPLAY
	initializes Ghostscript with a null device (a device that discards
the output image) rather than the default device or the device selected with
-sDEVICE=.  This is usually only useful when running PostScript code whose
purpose is to compute something rather than produce an output image.

-dNOFONTMAP
	suppresses the normal loading of the Fontmap file.  This may be
useful in environments without a file system.

-dNOFONTPATH
	suppresses consultation of GS_FONTPATH.  This may be useful for
debugging.

-dNOGC
	suppresses the initial automatic enabling of the garbage collector
in Level 2 systems.  (The vmreclaim operator is not disabled.)  Only useful
for debugging.

-dNOPAUSE
	disables the prompt and pause at the end of each page.  Normally one
should use this (along with -dBATCH) when producing output on a printer or
to a file; it also 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.

-dNOPROMPT
	disables only the prompt, but not the pause, at the end of each
page.  This may be useful on PC displays that get confused if a program
attempts to write text to the console while the display is in a graphics
mode.

-dORIENT1=true
-dORIENT1=false
	defines the meaning of the 0 and 1 orientation values for the
setpage[params] compatibility operators.  The default value of ORIENT1 is
true (set in gs_init.ps), which is the correct value for most files that use
setpage[params] at all, namely, files produced by badly designed
applications that 'know' that the output will be printed on certain
roll-media printers: these applications use 0 to mean landscape and 1 to
mean portrait.  -dORIENT1=false declares that 0 means portrait and 1 means
landscape, which is the convention used by a smaller number of files
produced by properly written applications.

-dQUIET
	suppresses routine information comments on stdout.  This is
currently necessary when redirecting device output to stdout.

-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.

-dSHORTERRORS
	makes certain error and information messages more Adobe-compatible.

-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.

-sFONTMAP=filename1;filename2;...
	specifies (an) alternate name(s) for the Fontmap file.  Note that
the names are separated by : on Unix systems, by ; on MS-DOS or MS Windows
systems, and by , on VMS systems, just as for search paths.

-sFONTPATH=dir1;dir2;...
	specifies a list of directories that will be scanned when looking
for fonts not found on the search path, overriding the GS_FONTPATH
environment variable.

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

-sSUBSTFONT=fontname
	causes the given font to be substituted for all unknown fonts,
instead of using the normal intelligent substitution algorithm.  Also, in
this case, the font returned by findfont will be the actual font named
fontname, not a copy of the font with the FontName changed to the requested
one.

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	Fill empty storage with a distinctive bit pattern
		for debugging.  Equivalent to -Z@.
	-A-	Turn off -A, equivalent to -Z-@.

	-E	Turn on tracing of error returns from operators.
		Equivalent to -Z#.
	-E-	Turn off -E, equivalent to -Z-#.

	-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).

	-Nn	Allocate space for nK names, rather than the default
		(normally 64K).  n > 64 is only allowed if the interpreter
		was compiled with EXTEND_NAMES defined.

	-Zxxx	Turn on debugging printout.
	-Z-xxx	Turn off debugging printout.
		Each of the xxx characters selects an option.
		Case is significant.
			0 = garbage collector, minimal detail
			1 = type 1 & type 42 font interpreter
			2 = curve subdivider/rasterizer
			  3 = curve subdivider/rasterizer, detail
			4 = garbage collector (strings)
			  5 = garbage collector (strings, detail)
			6 = garbage collector (chunks, roots)
			  7 = garbage collector (objects)
			  8 = garbage collector (refs)
			  9 = garbage collector (pointers)
			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
			  D = dictionary lookups
			e = external (OS-related) calls
			f = fill algorithm (summary)
			  F = fill algorithm (detail)
			g = gsave/grestore[all]
			h = halftone renderer
			  H = halftones, every pixel
			i = interpreter, just names
			  I = interpreter, everything
			j = (Japanese) composite fonts
			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)
			  O = stroke detail
			p = band list paths
			  P = all paths
			q = clipping
			r = arc renderer
			s = streams
			  S = scanner
			t = tiling algorithm
			u = undo saver (for save/restore), finalization
			  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
			# = operator error returns
			% = externally processed comments
			* = image parameters
			: = command list & allocator/time summary
			~ = math functions
		The following switches select debugging options other than
		printout.
			$ = set unused parts of object references to
				identifiable garbage values
			+ = use minimum-size stack blocks
			, = don't use path-based banding
			. = use small-memory table sizes even on
				large-memory machines
			? = validate pointers before, during and after GC,
				also before and after save and restore;
				also make other allocator validity checks
			@ = fill newly allocated, garbage-collected, and
				freed storage with a marker (a1, c1, and
				f1 respectively)

********
******** Frequently Asked Questions
********

Please consult our FAQ on the World-Wide Web at
	http://www.cs.wisc.edu/~ghost/gsfaq.html
or the text version at
	http://www.cs.wisc.edu/~ghost/gsfaq.txt