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)
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examples
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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
You can also
check the set of available devices from within Ghostscript:
invoke Ghostscript and type
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
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
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:
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
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:
or
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
for
instance
or
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.)
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
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. On a Debian system they are in /usr.
/usr/share/gs-gpl/#.##/*/*
Startup files, utilities, and basic font definitions
/usr/share/fonts/type1/gsfonts/*
More font definitions from the gsfonts package
/usr/share/doc/gs-gpl/examples/*
Ghostscript demonstration files
/usr/share/doc/gs-gpl/*
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. They are
"/usr/share/gs-gpl/#.## on a Debian system".
Each of these (GS_LIB_DEFAULT, GS_LIB, and
-I parameter) may be either a single directory or a list
of directories separated by ":".
safer mode
The -dSAFER option disables the "deletefile" and
"renamefile" operators and prohibits opening piped commands
("%pipe%cmd"). Only "%stdout" and "%stderr" can be opened
for writing. It also disables reading from files, except for
"%stdin", files given as a command line argument, and files
contained in paths given by LIBPATH and FONTPATH or specified by
the system params /FontResourceDir and /GenericResourceDir.
This mode also sets the .LockSafetyParams parameter of the
initial output device to protect against programs that attempt to
write to files using the OutputFile device parameter. Since the
device parameters specified on the command line, including
OutputFile, are set prior to SAFER mode, use of
"-sOutputFile=..." on the command line is unrestricted.
SAFER mode prevents changing the /GenericResourceDir,
/FontResourceDir, /SystemParamsPassword, and /StartJobPassword.
While SAFER mode is not the default, it is the default for many
wrapper scripts such as ps2pdf and may be the default in a
subsequent release of Ghostscript. 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.
When running with -dNOSAFER it is possible to perform a
"save" followed by ".setsafe", execute a file or procedure in
SAFER mode, and then use "restore" to return to NOSAFER mode. In
order to prevent the save object from being restored by the
foreign file or procedure, the ".runandhide" operator should be
used to hide the save object from the restricted procedure.
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.
-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. Strongly
recommended for spoolers, conversion scripts or other sensitive
environments where a badly written or malicious PostScript
program code must be prevented from changing important files.
-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.
version
This document was last revised for Ghostscript version 9.07.
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
bugs
See
http://bugs.ghostscript.com/ and the Usenet news group
comp.lang.postscript.
see also
The various
Ghostscript document files (above), especially
Use.htm.
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.