GS(1) GS(1)
NAME
gs - Aladdin Ghostscript (PostScript) interpreter
SYNOPSIS
gs [ options ] [ files ] ...
DESCRIPTION
Ghostscript is a programming language similar to Adobe Sys-
tems' 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, how-
ever, 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
-sDEVICE=xyz
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
selectdevice in the input language, or by setting the envi-
ronment variable GS_DEVICE. The order of precedence for
these alternatives, highest to lowest, is:
selectdevice
(command line)
GS_DEVICE
dfaxlow
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
-sOUTPUTFILE=foo%d.xyz
The %d may be any printf (see fprintf(2)) format specifica-
tion. 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
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GS(1) GS(1)
example,
-sOUTPUTFILE=|lp
Specifying the file - will send the files to standard out-
put; this also requires enabling the -q option.
Initialization files
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 direc-
tories 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/postscript/font.
The GS_LIB or -I parameters may be a single directory or a
colon-separated list.
Options
-- 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 ARGU-
MENTS 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 must not contain any white space.
-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
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GS(1) GS(1)
/name (35) def
-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 windows, that allow width and height
to be specified.
-rnumber
-rnumber1xnumber2
Equivalent to -dDEVICEXRESOLUTION=number1 and -dDEVICE-
YRESOLUTION= 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.
Note that gs_init.ps makes systemdict read-only, so the val-
ues 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.)
Special names
-dDISKFONTS
Causes individual character outlines to be loaded from
the disk the first time they are encountered. (Nor-
mally 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. Only useful for debugging.
-dNOBIND
Disables the `bind' operator. Only useful for debug-
ging.
-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 (e.g. page(1)) is `driving' Ghostscript.
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GS(1) GS(1)
-dSAFER
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 sen-
sitive environments.
-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 ini-
tial output device, as described above.
FILES
/sys/lib/ghostscript/*
Startup-files, utilities, examples, and basic font def-
initions.
/sys/lib/ghostscript/fonts/*
Additional font definitions.
SOURCE
/sys/src/cmd/gs
SEE ALSO
page(1)
The Ghostscript document files in the source directory.
BUGS
The treatment of standard input is non-standard.
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