You can get a help message by invoking Ghostscript with
gs -hor
gs -?
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
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
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.
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 DeskJet or 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
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.
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:
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 and MS-DOS systems).
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.
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:
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
Ghostscript looks for the following resources under the program name ``Ghostscript'':
To set these resources, put them in a file (such as ~/.Xdefaults in X11R3 or ~/.Xresources in X11R4 or X11R5) in the following form:
Ghostscript*geometry: 612x792-0+0
Ghostscript*xResolution: 72
Ghostscript*yResolution: 72
Then load the defaults into the X server:
% xrdb -merge ~/.Xresources
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.
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.)
The -T and -Z switch only applies if the interpreter was built for a debugging configuration (this is usually not the case for Ghostscript executables installed for public use).
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
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 = rectangle fill
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
z = trapezoid fill
spam% gs
Initializing... done.
Ghostscript 2.5.2 (9/19/92)
Copyright (C) 1990, 1992 Aladdin Enterprises, Menlo Park, CA.
All rights reserved.
Distributed by Free Software Foundation, Inc.
Ghostscript comes with NO WARRANTY: see the file LICENSE for details.
GS> 100 100 moveto 200 400 lineto stroke
GS> erasepage
GS> (/usr/um/lib/ghostscript/tiger.ps) run
>>showpage, press <return> to continue<<
GS> quit
At most installations, the only available display device is x11, so you must be running X11 windows to use ghostscript unless you use the command line option -dNODISPLAY. There is also a script called 'gsnd' which is just 'gs -DNODISPLAY -q $*'.
At most installations, Ghostscript was not built for a debugging configuration therefore the command line option -Zxxx is not available. This speeds up the interpreter.
Ghostscript works with color postscript files, postscript files created by Tom Rokicki's dvips, M-PLOT, Mathematica, Tell-a-Graf, etc. You can, for example, preview multiple pages of a postscript file created by Latex/dvips/psfig and you will be able to see any included postscript figure. If the postscript file adheres to Adobe's Document Structuring Convention, like the ones generated by Latex/dvips, then you are advised to use ghostview to preview your postscript document for it provides a far more friendly and graphical user interface.
Ghostscript also has the ability to convert a postscript file to a PPM file. Once you have a file in PPM format you can display or manipulate it in many ways. You can, for example, use 'xv' or other tools to convert the PPM file to a variety of formats, like GIF, TIFF, PICT, RLE, XPM, GPR (only available on the apollos, through the program /progs/bit2bit/bin/ppm2gpr) etc.
Example:
spam% gs
Initializing... done.
Ghostscript 2.5.2 (9/19/92)
Copyright (C) 1990, 1992 Aladdin Enterprises, Menlo Park, CA.
All rights reserved.
Distributed by Free Software Foundation, Inc.
Ghostscript comes with NO WARRANTY: see the file LICENSE for details.
GS> (pstoppm.ps) run
Usage: (file) ppmNrun
converts file.ps to file.ppm (single page),
or file.1ppm, file.2ppm, ... (multi page).
N is # of bits per pixel (1, 8, or 24).
Examples: (golfer) ppm1run ..or.. (escher) ppm8run
Optional commands you can give first:
horiz_DPI vert_DPI ppmsetdensity
(dirname/) ppmsetprefix
page_num ppmsetfirstpagenumber
GS> 100 120 ppmsetdensity
GS> (/tmp/) ppmsetprefix
GS> (tiger) ppm24run
Writing /tmp/tiger.ppm
GS> quit
spam% ppmtogif < /tmp/tiger.ppm > /tmp/tiger.gif
ppmtogif: computing colormap...
ppmtogif: 39 colors found
spam% ls -l tiger.ps /tmp/tiger.ppm /tmp/tiger.gif
-rw-r--r-- 1 oliveria 41796 Apr 21 18:44 /tmp/tiger.gif
-rw-r--r-- 1 oliveria 3366054 Apr 21 18:36 /tmp/tiger.ppm
-rw-r--r-- 1 oliveria 78519 Apr 21 17:39 tiger.ps
Notice that ppm24run creates huge files.
IslandDraw version 3.0 or greater is also able to read (select 'Convert...' under the 'File' menu) single-page postscript files. It can also save the postscript file in a variety of formats.
On a MS-DOS system, interrupting Ghostscript by typing ^C doesn't restore the display mode.
The Ghostscript language does not include the following operators of the PostScript language:
resetfile
banddevice, renderbands
The following are not implemented completely:
%statementedit (file name): interpreted as equivalent to %lineedit.
Most of the new color operators, particularly those that support the CMYK color model, are implemented as Ghostscript language procedures, and they essentially emulate CMYK using RGB.
The following operators that expect arrays won't accept packed arrays:
definefont (Subrs (type 1 fonts))
setdash (dash pattern)
setcachedevice (bounding box)
makeimagedevice (palette)
The file operator only recognizes modes r and w, not the newer modes r+, w+, a, and a+.
Floating point exceptions terminate Ghostscript, rather than producing a rangecheck error.
Some access checks aren't implemented.
copypage does nothing in the MS-DOS implementation, and merely synchronizes the X connection in the Unix implementation. showpage is a procedure that does a copypage and then beeps the bell and waits for the user to hit a key. (copypage does do the right thing for printers.)
strokepath produces incorrect output for dashed lines.
The implementation only looks at the PaintType of the font when doing show, not when doing charpath. Because of this, stroked fonts don't work correctly with charpath.
arcto gives an error for negative radii.
Changing the contents of the Encoding array or the Metrics dictionary of a font dynamically doesn't produce the expected result (may have no effect) if character caching is enabled.
Halftone patterns "flip over" at the 50% coverage point, producing anomalous visual effects on some color devices.
We have not been able to test 2-, 4-, and 16-bit memory devices as thoroughly as 1-, 8-, 24-, and 32-bit devices; please report any problems.
Opening more than one window device at the same time doesn't work. This is the case for both X Windows and Microsoft Windows.
restore doesn't properly undo currentgstate.
copy doesn't handle gstates.