gs - Ghostscript (PostScript and PDF language interpreter and previewer)
gs [
options ] [
files ] ...
The
gs 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 you have installed the ghostscript-x Debian package and are under X, the
default device is an X11 window (previewer), else ghostscript will 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".
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
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
-
-- 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.)
- -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.
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.
The locations of many Ghostscript run-time files are compiled into the
executable when it is built. Run "
gs -h" to find the
location of Ghostscript documentation on your system, from which you can get
more details. On a Debian system they are in
/usr.
- /usr/share/ghostscript/[0-9]*.[0.9]*/*
- Startup files, utilities, and basic font definitions (where
[0-9]*.[0.9]* is the ghostscript version)
- /usr/share/fonts/type1/gsfonts/*
- More font definitions from the gsfonts package
- /usr/share/doc/ghostscript/examples/*
- Ghostscript demonstration files (if ghostscript-doc package
is installed)
- /usr/share/doc/ghostscript/*
- Diverse document files (may need to install ghostscript-doc
package)
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), 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.
GS_LIB_DEFAULT is
"/usr/share/ghostscript/[0-9]*.[0-9]*/lib" on a Debian system
where "[0-9]*.[0-9]*" 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
":".
- 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
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
The various Ghostscript document files (above), especially
Use.htm. On
Debian you may need to install ghostscript-doc before reading the
documentation.
See
http://bugs.ghostscript.com/ and the Usenet news group comp.lang.postscript.
This document was last revised for Ghostscript version 10.00.0.
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.