Tech Arsenal 1/Tech Arsenal (Arsenal Computer).ISO/tek-04/gs24src.zip/USE.DOC

Text File | 1992-03-24 | 15KB | 413 lines

   Copyright (C) 1989, 1992 Aladdin Enterprises.  All rights reserved.
   Distributed by Free Software Foundation, Inc.

This file is part of Ghostscript.

Ghostscript is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY.  No author or distributor accepts responsibility
to anyone for the consequences of using it or for whether it serves any
particular purpose or works at all, unless he says so in writing.  Refer
to the Ghostscript General Public License for full details.

Everyone is granted permission to copy, modify and redistribute
Ghostscript, but only under the conditions described in the Ghostscript
General Public License.  A copy of this license is supposed to have been
given to you along with Ghostscript so you can know your rights and
responsibilities.  It should be in a file named COPYING.  Among other
things, the copyright notice and this notice must be preserved on all
copies.

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This file, use.doc, describes how to use the Ghostscript language
interpreter.

For an overview of Ghostscript and a list of the documentation files, see
README.

********
******** How to use the Ghostscript interpreter ********
********

The file name of the Ghostscript interpreter is gs.exe (MS-DOS and VMS) or
gs (Unix).  To run it, you also need some external initialization files:
    gconfig.ps
    gs_*.ps (gs_2asc.ps, gs_ccfnt.ps, gs_dps1.ps,
         gs_fonts.ps, gs_init.ps, gs_lev2.ps, gs_statd.ps)
    sym__enc.ps
    uglyr.gsf
    Fontmap
as well as any other fonts from the Ghostscript distribution (.gsf and
.pfa files).

To invoke the interpreter, give the command
    gs <filename1> ... <filenameN>
The interpreter will read in the files in sequence and execute them.
After doing this, it reads further input from the primary input stream
(normally the keyboard).  Each line (i.e. characters up to a <return>) is
interpreted separately.  To exit from the interpreter, type quit<return>.
The interpreter also exits gracefully if it encounters end-of-file.
Typing the interrupt character, e.g., control-C, is also safe.

The interpreter recognizes several switches described below, which may appear
anywhere in the command line and apply to all files thereafter.

You can get a help message by invoking Ghostscript with
    gs -h
or
    gs -?
This message also lists the available devices.  For a little more
information, a one-line description of each device appears near the
beginning of the file devs.mak.

Choosing the output device
--------------------------

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, you can get the lowest-density (fastest) Epson mode with
    gs -sDEVICE=epson -r60x60
the highest-density 9-pin mode with
    gs -sDEVICE=epson -r240x60
and the highest-density 24-pin mode with
    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.  To pipe the
output to the command printit, use the switch
    -sOUTPUTFILE=\|printit

To find out what devices are available, type
    devicenames ==

File searching
--------------

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:

    - The directory/ies specified by the -I switch(es) in the command
      line (see below), if any;

    - The directory/ies specified by the GS_LIB environment variable,
      if any;

    - The directory/ies specified by the GS_LIB_DEFAULT macro in the
      Ghostscript makefile, if any.

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
systems, ';' on MS-DOS systems).

VMS-specific notes
------------------

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

MS-DOS notes
------------

If you compiled Ghostscript with the Watcom compiler, you must insert the
following line in your AUTOEXEC.BAT:

    set GS_RUN_EXE=dos4gw

If you are running Ghostscript on a MS-DOS machine with a display that is
not EGA/VGA compatible, 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:

    BGIPATH - defines the directory where Ghostscript will look for
the appropriate BGI driver.  If BGIPATH is not defined, Ghostscript will
look in the directory defined as BGIDIR in the makefile.  In either case,
if no driver is found in the designated directory, Ghostscript will look
in the current directory.

    BGIUSER - a string of the form nn.dname, where nn is a hexadecimal
number giving a display mode and dname is the name of a file containing a
user-supplied BGI driver.  If BGIUSER is defined and the BGI device is
selected, Ghostscript will supply nn as the display mode and will obtain
the driver from the file named dname.

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

X Windows resources
-------------------

Ghostscript 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 = ???
    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

To set these resources, put them in a file (such as ~/.Xdefaults) 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 ~/.Xdefaults

Normal switches
---------------

    -- 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 must not contain any 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

    -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 and VESA displays) that require
        (or allow) width and height to be specified.

    -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.

    -Idirectories
        Adds the designated list of directories at the head of the
        search path for library files.

    -
        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.)

Special names
-------------

-dASCIIOUT
    disables Ghostscript's normal behavior; instead, writes strings to
stdout that would have been displayed or printed.  For more information,
see the file gs_2asc.ps.

-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.

-dNOBIND
    disables the 'bind' operator.  Only useful for debugging.

-dNOCACHE
    disables character caching.  Only useful 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.

-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.

Debugging switches
------------------

The -T and -Z switches only apply if the interpreter was built for a
debugging configuration.

    -A    Turn on allocator debugging.

    -e    Turn on tracing of error returns from operators.

    -E    Abort when any operator returns with an error.

    -Mn    Force the interpreter's allocator to acquire additional
        memory in units of nK, rather than the default (currently
        20K on MS-DOS systems, 50K on Unix).  n is a positive
        decimal integer (not exceeding 63 on MS-DOS systems).

    -Tname:rsize:format
        (Only available on MS-DOS systems.)
        Trace a procedure within Ghostscript.  Any number of
        procedures may be traced.  rsize is the size of the value
        returned by the procedure, in bytes; if omitted, the value
        returned by the procedure is not printed.  format is a
        printf-style template for printing the arguments; if
        omitted, the arguments are printed in hex.  Note that
        MS-DOS provides no way to quote spaces or commas within a
        command line argument.

    -Zxxx    Turn on debugging printout.
        Each of the xxx characters selects an option:
        if the string is empty, all options are selected.
        Case is significant.
            0 = type 1 path tracer (type1imagepath)
            1 = type 1 font interpreter (type1addpath)
            2 = curve subdivider
            a = allocator (large blocks only)
              A = allocator (all calls)
            b = bitmap image processor
              B = bitmap images, detail
            c = color/halftone mapper
            d = dictionary lookup
            f = fill algorithm (summary)
              F = fill algorithm (detail)
            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
            o = outliner (stroke)
            p = path tracer
            q = clipping
            r = arc renderer
            s = scanner
            t = tiling algorithm
            u = undo saver (for save/restore)
            v = rectangle fill
              V = device-level output
            w = LZW encoder/decoder
            x = transformations