gs - Aladdin Ghostscript (PostScript) interpreter
gs [ options ] [ files ] ...
Ghostscript is a programming language similar to Adobe Systems' PostScript language, which
is in turn similar to Forth. Gs reads files in sequence and executes them as Ghostscript
programs. After doing this, it reads further input from the standard input. If the file
- is named, however, it represents the standard input, which is read in order and not
after the files on the command line. Each line is interpreted separately. The `quit'
command, or end-of-file, exits the interpreter.
The interpreter recognizes several switches described below, which may appear anywhere in
the command line and apply to all files thereafter.
The -h or -? options give help and list the available devices; the default is dfaxlow,
which produces CCITT Group 3 fax files suitable for viewing with page(1) (but note that
page(1) will invoke gs automatically; see its manual).
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
in the command line. This switch must precede the first PostScript file and only its
first invocation has any effect. Output devices can also be selected by the word select-
device in the input language, or by setting the environment variable GS_DEVICE. The order
of precedence for these alternatives, highest to lowest, is:
Normally, output goes directly to a scratch file. To send the output to a series of files
foo1.xyz, foo2.xyz, etc., use the switch
The %d may be any printf (see fprintf(2)) format specification. Each file will receive
one page of output. If the file name begins with a pipe character, the output will be
sent as standard input to the following pipeline. For example,
Specifying the file - will send the files to standard output; this also requires enabling
the -q option.
When looking for the initialization files (gs_*.ps), the files related to fonts, or the
file for the run operator, Ghostscript first looks for the file (if it doesn't start with
a slash) in the current directory, then in these directories in the following order:
1. Any directories specified by -I switches in the command line (see below);
2. Any directories specified by the GS_LIB environment variable;
3. The directories /sys/lib/ghostscript, /sys/lib/ghostscript/font, and /sys/lib/post-
The GS_LIB or -I parameters may be a single directory or a colon-separated list.
-- filename arg1 ...
Take the next argument as a file name as usual, but take all remaining arguments
(even if they have the syntactic form of switches) and define 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.
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 white
-dname Define a name in systemdict with value=null.
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
-q Quiet startup: suppress normal startup messages, and also do the equivalent of
Equivalent to -dDEVICEWIDTH=number1 and -dDEVICEHEIGHT=number2. This is for the
benefit of devices, such as windows, that allow width and height to be specified.
Equivalent to -dDEVICEXRESOLUTION=number1 and -dDEVICEYRESOLUTION= number2. This
is for the benefit of devices, such as printers, that support multiple X and Y res-
olutions. If only one number is given, it is used for both X and Y resolutions.
Adds the designated list of directories at the head of the search path for library
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.)
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
Disables character caching. Only useful for debugging.
Disables the `bind' operator. Only useful for debugging.
Suppresses the normal initialization of the output device. This may be useful when
Disables the prompt and pause at the end of each page. This may be desirable for
applications where another program (e.g. page(1)) is `driving' Ghostscript.
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 sensi-
Leaves systemdict writable. This is necessary when running special utility pro-
grams such as font2c and pcharstr, which must bypass normal PostScript access pro-
Selects an alternate initial output device, as described above.
Selects an alternate output file (or pipe) for the initial output device, as
Startup-files, utilities, examples, and basic font definitions.
Additional font definitions.
The Ghostscript document files in the source directory.
The treatment of standard input is non-standard.