GS(1) Ghostscript GS(1)

NAME

gs - Ghostscript (PostScript and PDF language interpreter and
previewer)

SYNOPSIS

gs [ options ] [ files ] ... (Unix, VMS)
gswin32c [ options ] [ files ] ... (MS Windows)
gswin32 [ options ] [ files ] ... (MS Windows 3.1)
gsos2 [ options ] [ files ] ... (OS/2)

DESCRIPTION

The gs (gswin32c, gswin32, gsos2) command invokes Ghostscript, an
interpreter of Adobe Systems' PostScript(tm) and Portable Document
Format (PDF) languages. gs reads "files" in sequence and executes
them as Ghostscript programs. After doing this, it reads further
input from the standard input stream (normally the keyboard),
interpreting each line separately and output to an output device (may
be a file or an X11 window preview, see below). The interpreter exits
gracefully when it encounters the "quit" command (either in a file or
from the keyboard), at end-of-file, or at an interrupt signal (such
as Control-C at the keyboard).

The interpreter recognizes many option switches, some of which are
described below. Please see the usage documentation for complete
information. Switches may appear anywhere in the command line and
apply to all files thereafter. Invoking Ghostscript with the -h or
-? switch produces a message which shows several useful switches, all
the devices known to that executable, and the search path for fonts;
on Unix it also shows the location of detailed documentation.

Ghostscript may be built to use many different output devices. To
see which devices your executable includes, run "gs -h".

Unless you specify a particular device, Ghostscript normally opens
the first one of those and directs output to it.

If built with X11 support, often the default device is an X11 window
(previewer), else ghostscript will typically use the bbox device and
print on stdout the dimension of the postscript file.

So if the first one in the list is the one you want to use, just
issue the command

gs myfile.ps

You can also check the set of available devices from within
Ghostscript: invoke Ghostscript and type

devicenames ==

but the first device on the resulting list may not be the default
device you determine with "gs -h". To specify "AbcXyz" as the
initial output device, include the switch

-sDEVICE=AbcXyz

For example, for output to an Epson printer you might use the command

gs -sDEVICE=epson myfile.ps

The "-sDEVICE=" switch must precede the first mention of a file to
print, and only the switch's first use has any effect.

Finally, you can specify a default device in the environment variable
GS_DEVICE. The order of precedence for these alternatives from
highest to lowest (Ghostscript uses the device defined highest in the
list) is:

Some devices can support different resolutions (densities). To
specify the resolution on such a printer, use the "-r" switch:

gs -sDEVICE=<device> -r<xres>x<yres>

For example, on a 9-pin Epson-compatible printer, you get the lowest-
density (fastest) mode with

gs -sDEVICE=epson -r60x72

and the highest-density (best output quality) mode with

gs -sDEVICE=epson -r240x72.

If you select a printer as the output device, Ghostscript also allows
you to choose where Ghostscript sends the output -- on Unix systems,
usually to a temporary file. To send the output to a file "foo.xyz",
use the switch

-sOutputFile=foo.xyz

You might want to print each page separately. To do this, send the
output to a series of files "foo1.xyz, foo2.xyz, ..." using the
"-sOutputFile=" switch with "%d" in a filename template:

-sOutputFile=foo%d.xyz

Each resulting file receives one page of output, and the files are
numbered in sequence. "%d" is a printf format specification; you can
also use a variant like "%02d".

On Unix and MS Windows systems you can also send output to a pipe.
For example, to pipe output to the "lpr" command (which, on many Unix
systems, directs it to a printer), use the option

-sOutputFile=%pipe%lpr

Note that the '%' characters need to be doubled on MS Windows to
avoid mangling by the command interpreter.

You can also send output to standard output:

-sOutputFile=-
or
-sOutputFile=%stdout%

In this case you must also use the -q switch, to prevent Ghostscript
from writing messages to standard output.

To select a specific paper size, use the command line switch

-sPAPERSIZE=<paper_size>

for instance

-sPAPERSIZE=a4
or
-sPAPERSIZE=legal

Most ISO and US paper sizes are recognized. See the usage
documentation for a full list, or the definitions in the
initialization file "gs_statd.ps".

Ghostscript can do many things other than print or view PostScript
and PDF files. For example, if you want to know the bounding box of
a PostScript (or EPS) file, Ghostscript provides a special "device"
that just prints out this information.

For example, using one of the example files distributed with
Ghostscript,

gs -sDEVICE=bbox golfer.ps

prints out

%%BoundingBox: 0 25 583 732
%%HiResBoundingBox: 0.808497 25.009496 582.994503 731.809445

OPTIONS

-- 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 may contain no 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

-P Makes Ghostscript to look first in the current directory for
library files. By default, Ghostscript no longer looks in the
current directory, unless, of course, the first explicitly
supplied directory is "." in -I. See also the INITIALIZATION
FILES section below, and bundled Use.htm for detailed
discussion on search paths and how Ghostcript finds files.

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

-gnumber1xnumber2
Equivalent to -dDEVICEWIDTH=number1 and
-dDEVICEHEIGHT=number2. This is for the benefit of devices
(such as X11 windows) 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. If only one number is given, it is used for both
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, but indicates to Ghostscript that
standard input is coming from a file or a pipe and not
interactively from the command line. Ghostscript reads from
standard input until it reaches end-of-file, executing it like
any other file, and then continues with processing the command
line. When the command line has been entirely processed,
Ghostscript exits rather than going into its interactive mode.

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

SPECIAL NAMES

-dNOCACHE
Disables character caching. Useful only for debugging.

-dNOBIND
Disables the "bind" operator. Useful only 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
(for instance X Windows). This may be needed if the platform
fonts look undesirably different from the scalable fonts.

-dSAFER
Restricts file operations the job can perform. Now the default
mode of operation.

-dWRITESYSTEMDICT
Leaves "systemdict" writable. This is necessary when running
special utility programs, but is strongly discouraged as it
bypasses normal Postscript security measures.

-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.

SAFER MODE

The -dSAFER option restricts file system accesses to those files and
directories allowed by the relevant environment variables (such as
GS_LIB) or by the command line parameters (see
https://ghostscript.com/doc/current/Use.htm for details).

SAFER mode is now the default mode of operation. Thus when running
programs that need to open files or set restricted parameters you
should pass the -dNOSAFER command line option or its synonym
-dDELAYSAFER.

Running with NOSAFER/DELAYSAFER (as the same suggests) loosens the
security and is thus recommended ONLY for debugging or in VERY
controlled workflows, and strongly NOT recommended in any other
circumstances.

FILES

The locations of many Ghostscript run-time files are compiled into
the executable when it is built. On Unix these are typically based
in /usr/local, but this may be different on your system. Under DOS
they are typically based in C:\GS, but may be elsewhere, especially
if you install Ghostscript with GSview. Run "gs -h" to find the
location of Ghostscript documentation on your system, from which you
can get more details.

/usr/local/share/ghostscript/#.##/*
Startup files, utilities, and basic font definitions

/usr/local/share/ghostscript/fonts/*
More font definitions

/usr/local/share/ghostscript/#.##/examples/*
Ghostscript demonstration files

/usr/local/share/ghostscript/#.##/doc/*
Diverse document files

INITIALIZATION FILES

When looking for the initialization files "gs_*.ps", the files
related to fonts, or the file for the "run" operator, Ghostscript
first tries to open the file with the name as given, using the
current working directory if no directory is specified. If this
fails, and the file name doesn't specify an explicit directory or
drive (for instance, doesn't contain "/" on Unix systems or "\" on MS
Windows systems), Ghostscript tries directories in this order:

1. the directories specified by the -I switches in the command line
(see below), if any;

2. the directories specified by the GS_LIB environment variable, if
any;

3. the directories specified by the GS_LIB_DEFAULT macro in the
Ghostscript makefile when the executable was built. When gs is
built on Unix, GS_LIB_DEFAULT is usually
"/usr/local/share/ghostscript/#.##:/usr/local/share/ghostscript/fonts"
where "#.##" represents the Ghostscript version number.

Each of these (GS_LIB_DEFAULT, GS_LIB, and -I parameter) may be
either a single directory or a list of directories separated by ":".

ENVIRONMENT

GS_OPTIONS
String of options to be processed before the command line
options

GS_DEVICE
Used to specify an output device

GS_FONTPATH
Path names used to search for fonts

GS_LIB Path names for initialization files and fonts

TEMP Where temporary files are made

X RESOURCES

Ghostscript, or more properly the X11 display device, looks for the
following resources under the program name "Ghostscript":

borderWidth
The border width in pixels (default = 1).

borderColor
The name of the border color (default = black).

geometry
The window size and placement, WxH+X+Y (default is NULL).

xResolution
The number of x pixels per inch (default is computed from
WidthOfScreen and WidthMMOfScreen).

yResolution
The number of y pixels per inch (default is computed from
HeightOfScreen and HeightMMOfScreen).

useBackingPixmap
Determines whether backing store is to be used for saving
display window (default = true).

See the usage document for a more complete list of resources. To set
these resources on Unix, put them in a file such as "~/.Xresources"
in the following form:

Ghostscript*geometry: 612x792-0+0
Ghostscript*xResolution: 72
Ghostscript*yResolution: 72

Then merge these resources into the X server's resource database:

% xrdb -merge ~/.Xresources

SEE ALSO

The various Ghostscript document files (above), especially Use.htm.

BUGS

See http://bugs.ghostscript.com/ and the Usenet news group
comp.lang.postscript.

VERSION

This document was last revised for Ghostscript version 10.03.1.

AUTHOR

Artifex Software, Inc. are the primary maintainers of Ghostscript.
Russell J. Lang, gsview at ghostgum.com.au, is the author of most of
the MS Windows code in Ghostscript.

10.03.1 06 May 2024 GS(1)