Configuring PSPP
****************

PSPP has dozens of configuration possibilities and hundreds of settings.  This is both a bane and a blessing.  On one hand, it's possible to easily accommodate diverse ranges of setups.  But, on the other, the multitude of possibilities can overwhelm the casual user. Fortunately, the configuration mechanisms are profusely described in the sections below...

Locating configuration files
============================

PSPP uses the same method to find most of its configuration files:

 1. The base name of the file being sought is determined.

 2. The path to search is determined.

 3. Each directory in the search path, from left to right, is searched for a file with the name of the base name.  The first occurrence is read as the configuration file.

The first two steps are elaborated below for the sake of our pedantic friends.

 1. A base name is a file name lacking an absolute directory reference.  Some examples of base names are: ps-encodings, devices, devps/DESC (under UNIX), devps\DESC (under M$ environments).

     Determining the base name is a two-step process:

      a. If the appropriate environment variable is defined, the value of that variable is used (see Environment variables).  For instance, when searching for the output driver initialization file, the variable examined is STAT_OUTPUT_INIT_FILE.

      b. Otherwise, the compiled-in default is used.  For example, when searching for the output driver initialization file, the default base name is devices.

     Please note: If a user-specified base name does contain an absolute directory reference, as in a file name like /home/pfaff/fonts/TR, no path is searched---the file name is used exactly as given---and the algorithm terminates.

 2. The path is the first of the following that is defined:

       * A variable definition for the path given in the user environment.  This is a PSPP-specific environment variable name; for instance, STAT_OUTPUT_INIT_PATH.

       * In some cases, another, less-specific environment variable is checked. For instance, when searching for font files, the PostScript driver first checks for a variable with name STAT_GROFF_FONT_PATH, then for one with name GROFF_FONT_PATH.  (However, font searching has its own list of esoteric search rules.)

       * The configuration file path, which is itself determined by the following rules:

           a. If the command line contains an option of the form -B PATH or --config-dir=PATH, then the value given on the rightmost occurrence of such an option is used.

           b. Otherwise, if the environment variable STAT_CONFIG_PATH is defined, the value of that variable is used.

           c. Otherwise, the compiled-in fallback default is used.  On UNIX machines, the default fallback path is

                1. ~/.pspp

                2. /usr/local/lib/pspp

                3. /usr/lib/pspp

               On DOS machines, the default fallback path is:

                1. All the paths from the DOS search path in the PATH environment variable, in left-to-right order.

                2. C:\PSPP, as a last resort.

               Note that the installer of PSPP can easily change this default fallback path; thus the above should not be taken as gospel.

As a final note: Under DOS, directories given in paths are delimited by semicolons (;); under UNIX, directories are delimited by colons (:).  This corresponds with the standard path delimiter under these OSes.

Configuration techniques
========================

There are many ways that PSPP can be configured.  These are described in the list below.  Values given by earlier items take precedence over those given by later items.

 1. Syntax commands that modify settings, such as SET.  See SET.

 2. Command-line options.  See Invocation.

 3. PSPP-specific environment variable contents.  See Environment variables.

 4. General environment variable contents.  See Environment variables.

 5. Configuration file contents.  See Configuration files.

 6. Fallback defaults.

Some of the above may not apply to a particular setting.  For instance, the current pager (such as more, most, or less) cannot be determined by configuration file contents because there is no appropriate configuration file.

Configuration files
===================

Most configuration files have a common form:

  * Each line forms a separate command or directive.  This means that lines cannot be broken up, unless they are spliced together with a trailing backslash, as described below.

  * Before anything else is done, trailing whitespace is removed.

  * When a line ends in a backslash (\), the backslash is removed, and the next line is read and appended to the current line.

       - Whitespace preceding the backslash is retained.

       - This rule continues to be applied until the line read does not end in a backslash.

       - It is an error if the last line in the file ends in a backslash.

  * Comments are introduced by an octothorpe (#), and continue until the end of the line.

       - An octothorpe inside balanced pairs of double quotation marks (") or single quotation marks (') does not introduce a comment.

       - The backslash character can be used inside balanced quotes of either type to escape the following character as a literal character.

          (This is distinct from the use of a backslash as a line-splicing character.)

       - Line splicing takes place before comment removal.

  * Blank lines, and lines that contain only whitespace, are ignored.

Environment variables
=====================

You may think the concept of environment variables is a fairly simple one.  However, the author of PSPP has found a way to complicate even something so simple.  Environment variables are further described in the sections below:

Values of environment variables
-------------------------------

Values for environment variables are obtained by the following means, which are arranged in order of decreasing precedence:

 1. Command-line options.  See Invocation.

 2. The environment configuration file---more on this below.

 3. Actual environment variables (defined in the shell or other parent process).

The environment configuration file is located through application of the usual algorithm for configuration files (see File locations), except that its contents do not affect the search path used to find environment itself.  Use of environment is discouraged on systems that allow an arbitrarily large environment; it is supported for use on systems like MS-DOS that limit environment size.

environment is composed of lines having the form KEY=VALUE, where KEY and the equals sign (=) are required, and VALUE is optional.  If VALUE is given, variable KEY is given that value; if VALUE is absent, variable KEY is undefined (deleted).  Variables may not be defined with a null value.

Environment substitutions are performed on each line in the file (see Environment substitutions).

See Configuration files, for more details on formatting of the environment configuration file.

     Please note: Support for environment is not yet implemented.

Environment substitutions
-------------------------

Much of the power of environment variables lies in the way that they may be substituted into configuration files.  Variable substitutions are described below.

The line is scanned from left to right.  In this scan, all characters other than dollar signs ($) are retained unmolested.  Dollar signs, however, introduce an environment variable reference.  References take three forms:

$VAR
     Replaced by the value of environment variable VAR, determined as specified in Variable values.  VAR must be one of the following:

       * One or more letters.

       * Exactly one nonalphabetic character.  This may not be a left brace ({).

${VAR}
     Same as above, but VAR may contain any character (except }).

$$
     Replaced by a single dollar sign.

Undefined variables expand to a empty value.

Predefined environment variables
--------------------------------

There are two environment variables predefined for use in environment substitutions:

VER
     Defined as the version number of PSPP, as a string, in a format something like 0.9.4.

ARCH
     Defined as the host architecture of PSPP, as a string, in standard cpu-manufacturer-OS format.  For instance, Debian GNU/Linux 1.1 on an Intel machine defines this as i586-unknown-linux.  This is somewhat dependent on the system used to compile PSPP.

Nothing prevents these values from being overridden, although it's a good idea not to do so.

Output devices
==============

Configuring output devices is the most complicated aspect of configuring PSPP.  The output device configuration file is named devices.  It is searched for using the usual algorithm for finding configuration files (see File locations).  Each line in the file is read in the usual manner for configuration files (see Configuration files).

Lines in devices are divided into three categories, described briefly in the table below:

driver category definitions
     Define a driver in terms of other drivers.

macro definitions
     Define environment variables local to the the output driver configuration file.

device definitions
     Describe the configuration of an output device.

The following sections further elaborate the contents of the devices file.

Driver categories
-----------------

Drivers can be divided into categories.  Drivers are specified by their names, or by the names of the categories that they are contained in. Only certain drivers are enabled each time PSPP is run; by default, these are the drivers in the category `default'.  To enable a different set of drivers, use the -o DEVICE command-line option (see Invocation).

Categories are specified with a line of the form CATEGORY=DRIVER1 DRIVER2 DRIVER3 ... DRIVERN.  This line specifies that the category CATEGORY is composed of drivers named DRIVER1, DRIVER2, and so on.  There may be any number of drivers in the category, from zero on up.

Categories may also be specified on the command line (see Invocation).

This is all you need to know about categories.  If you're still curious, read on.

First of all, the term `categories' is a bit of a misnomer.  In fact, the internal representation is nothing like the hierarchy that the term seems to imply: a linear list is used to keep track of the enabled drivers.

When PSPP first begins reading devices, this list contains the name of any drivers or categories specified on the command line, or the single item `default' if none were specified.

Each time a category definition is specified, the list is searched for an item with the value of CATEGORY.  If a matching item is found, it is deleted.  If there was a match, the list of drivers (DRIVER1 through DRIVERN) is then appended to the list.

Each time a driver definition line is encountered, the list is searched. If the list contains an item with that driver's name, the driver is enabled and the item is deleted from the list.  Otherwise, the driver is not enabled.

It is an error if the list is not empty when the end of devices is reached.

Macro definitions
-----------------

Macro definitions take the form define MACRONAME DEFINITION.  In such a macro definition, the environment variable MACRONAME is defined to expand to the value DEFINITION. Before the definition is made, however, any macros used in DEFINITION are expanded.

Please note the following nuances of macro usage:

  * For the purposes of this section, macro and environment variable are synonyms.

  * Macros may not take arguments.

  * Macros may not recurse.

  * Macros are just environment variable definitions like other environment variable definitions, with the exception that they are limited in scope to the devices configuration file.

  * Macros override other all environment variables of the same name (within the scope of devices).

  * Earlier macro definitions for a particular KEY override later ones.  In particular, macro definitions on the command line override those in the device definition file.  See Non-option Arguments.

  * There are two predefined macros, whose values are determined at runtime:

     viewwidth
          Defined as the width of the console screen, in columns of text.

     viewlength
          Defined as the length of the console screen, in lines of text.

Driver definitions
------------------

Driver definitions are the ultimate purpose of the devices configuration file.  These are where the real action is.  Driver definitions tell PSPP where it should send its output.

Each driver definition line is divided into four fields.  These fields are delimited by colons (:).  Each line is subjected to environment variable interpolation before it is processed further (see Environment substitutions).  From left to right, the four fields are, in brief:

driver name
     A unique identifier, used to determine whether to enable the driver.

class name
     One of the predefined driver classes supported by PSPP.  The currently supported driver classes include `postscript' and `ascii'.

device type(s)
     Zero or more of the following keywords, delimited by spaces:

     screen

          Indicates that the device is a screen display.  This may reduce the amount of buffering done by the driver, to make interactive use more convenient.

     printer

          Indicates that the device is a printer.

     listing

          Indicates that the device is a listing file.

     These options are just hints to PSPP and do not cause the output to be directed to the screen, or to the printer, or to a listing file---those must be set elsewhere in the options.  They are used primarily to decide which devices should be enabled at any given time.  See SET, for more information.

options
     An optional set of options to pass to the driver itself.  The exact format for the options varies among drivers.

The driver is enabled if:

 1. Its driver name is specified on the command line, or

 2. It's in a category specified on the command line, or

 3. If no categories or driver names are specified on the command line, it is in category default.

For more information on driver names, see Driver categories.

The class name must be one of those supported by PSPP.  The classes supported depend on the options with which PSPP was compiled.  See later sections in this chapter for descriptions of the available driver classes.

Options are dependent on the driver.  See the driver descriptions for details.

Dimensions
----------

Quite often in configuration it is necessary to specify a length or a size.  PSPP uses a common syntax for all such, calling them collectively by the name dimensions.

  * You can specify dimensions in decimal form (12.5) or as fractions, either as mixed numbers (12-1/2) or raw fractions (25/2).

  * A number of different units are available.  These are suffixed to the numeric part of the dimension.  There must be no spaces between the number and the unit.  The available units are identical to those offered by the popular typesetting system TeX:

     in
          inch (1 in = 2.54 cm)

     "
          inch (1 in = 2.54 cm)

     pt
          printer's point (1 in = 72.27 pt)

     pc
          pica (12 pt = 1 pc)

     bp
          PostScript point (1 in = 72 bp)

     cm
          centimeter

     mm
          millimeter (10 mm = 1 cm)

     dd
          didot point (1157 dd = 1238 pt)

     cc
          cicero (1 cc = 12 dd)

     sp
          scaled point (65536 sp = 1 pt)

  * If no explicit unit is given, PSPP attempts to guess the best unit:

       - Numbers less than 50 are assumed to be in inches.

       - Numbers 50 or greater are assumed to be in millimeters.

Paper sizes
-----------

Output drivers usually deal with some sort of hardcopy media.  This media is called paper by the drivers, though in reality it could be a transparency or film or thinly veiled sarcasm.  To make it easier for you to deal with paper, PSPP allows you to have (of course!) a configuration file that gives symbolic names, like ``letter'' or ``legal'' or ``a4'', to paper sizes, rather than forcing you to use cryptic numbers like ``8-1/2 x 11'' or ``210 by 297''.  Surprisingly enough, this configuration file is named papersize. See Configuration files.

When PSPP tries to connect a symbolic paper name to a paper size, it reads and parses each non-comment line in the file, in order.  The first field on each line must be a symbolic paper name in double quotes. Paper names may not contain double quotes.  Paper names are not case-sensitive: legal and Legal are equivalent.

If a match is found for the paper name, the rest of the line is parsed. If it is found to be a pair of dimensions (see Dimensions) separated by either x or by, then those are taken to be the paper size, in order of width followed by length.  There must be at least one space on each side of x or by.

Otherwise the line must be of the form "PAPER-1"="PAPER-2".  In this case the target of the search becomes paper name PAPER-2 and the search through the file continues.

How lines are divided into types
--------------------------------

The lines in devices are distinguished in the following manner:

 1. Leading whitespace is removed.

 2. If the resulting line begins with the exact string define, followed by one or more whitespace characters, the line is processed as a macro definition.

 3. Otherwise, the line is scanned for the first instance of a colon (:) or an equals sign (=).

 4. If a colon is encountered first, the line is processed as a driver definition.

 5. Otherwise, if an equals sign is encountered, the line is processed as a macro definition.

 6. Otherwise, the line is ill-formed.

How lines are divided into tokens
---------------------------------

Each driver definition line is run through a simple tokenizer.  This tokenizer recognizes two basic types of tokens.

The first type is an equals sign (=).  Equals signs are both delimiters between tokens and tokens in themselves.

The second type is an identifier or string token.  Identifiers and strings are equivalent after tokenization, though they are written differently.  An identifier is any string of characters other than whitespace or equals sign.

A string is introduced by a single- or double-quote character (' or ") and, in general, continues until the next occurrence of that same character.  The following standard C escapes can also be embedded within strings:

\'
     A single-quote (').

\"
     A double-quote (").

\?
     A question mark (?).  Included for hysterical raisins.

\\
     A backslash (\).

\a
     Audio bell (ASCII 7).

\b
     Backspace (ASCII 8).

\f
     Formfeed (ASCII 12).

\n
     New-line (ASCII 10)

\r
     Carriage return (ASCII 13).

\t
     Tab (ASCII 9).

\v
     Vertical tab (ASCII 11).

\OOO
     Each o must be an octal digit.  The character is the one having the octal value specified.  Any number of octal digits is read and interpreted; only the lower 8 bits are used.

\xHH
     Each h must be a hex digit.  The character is the one having the hexadecimal value specified.  Any number of hex digits is read and interpreted; only the lower 8 bits are used.

Tokens, outside of quoted strings, are delimited by whitespace or equals signs.

The PostScript driver class
===========================

The postscript driver class is used to produce output that is acceptable to PostScript printers and to PC-based PostScript interpreters such as Ghostscript.  Continuing a long tradition, PSPP's PostScript driver is configurable to the point of absurdity.

There are actually two PostScript drivers.  The first one, postscript, produces ordinary DSC-compliant PostScript output. The second one epsf, produces an Encapsulated PostScript file. The two drivers are otherwise identical in configuration and in operation.

The PostScript driver is described in further detail below.

PostScript output options
-------------------------

These options deal with the form of the output and the output file itself:

output-file=FILENAME

     File to which output should be sent.  This can be an ordinary filename (i.e., "pspp.ps"), a pipe filename (i.e., "|lpr"), or stdout ("-").  Default: "pspp.ps".

color=BOOLEAN

     Most of the time black-and-white PostScript devices are smart enough to map colors to shades themselves.  However, you can cause the PSPP output driver to do an ugly simulation of this in its own driver by turning color off.  Default: on.

     This is a boolean setting, as are many settings in the PostScript driver.  Valid positive boolean values are on, true, yes, and nonzero integers.  Negative boolean values are off, false, no, and zero.

data=DATA-TYPE

     One of clean7bit, clean8bit, or binary.  This controls what characters will be written to the output file.  PostScript produced with clean7bit can be transmitted over 7-bit transmission channels that use ASCII control characters for line control.  clean8bit is similar but allows characters above 127 to be written to the output file.  binary allows any character in the output file.  Default: clean7bit.

line-ends=LINE-END-TYPE

     One of cr, lf, or crlf.  This controls what is used for new-line in the output file.  Default: cr.

optimize-line-size=LEVEL

     Either 0 or 1.  If LEVEL is 1, then short line segments will be collected and merged into longer ones.  This reduces output file size but requires more time and memory.  A LEVEL of 0 has the advantage of being better for interactive environments.  1 is the default unless the screen flag is set; in that case, the default is 0.

optimize-text-size=LEVEL

     One of 0, 1, or 2, each higher level representing correspondingly more aggressive space savings for text in the output file and requiring correspondingly more time and memory.  Unfortunately the levels presently are all the same.  1 is the default unless the screen flag is set; in that case, the default is 0.

PostScript page options
-----------------------

These options affect page setup:

headers=BOOLEAN

     Controls whether the standard headers showing the time and date and title and subtitle are printed at the top of each page.  Default: on.

paper-size=PAPER-SIZE

     Paper size, either as a symbolic name (i.e., letter or a4) or specific measurements (i.e., 8-1/2x11 or "210 x 297". See Paper sizes.  Default: letter.

orientation=ORIENTATION

     Either portrait or landscape.  Default: portrait.

left-margin=DIMENSION
right-margin=DIMENSION
top-margin=DIMENSION
bottom-margin=DIMENSION

     Sets the margins around the page.  The headers, if enabled, are not included in the margins; they are in addition to the margins.  For a description of dimensions, see Dimensions.  Default: 0.5in.

PostScript file options
-----------------------

Oh, my.  You don't really want to know about the way that the PostScript driver deals with files, do you?  Well I suppose you're entitled, but I warn you right now: it's not pretty.  Here goes...

First let's look at the options that are available:

font-dir=FONT-DIRECTORY

     Sets the font directory.  Default: devps.

prologue-file=PROLOGUE-FILE-NAME

     Sets the name of the PostScript prologue file.  You can write your own prologue, though I have no idea why you'd want to: see Prologue. Default: ps-prologue.

device-file=DEVICE-FILE-NAME

     Sets the name of the Groff-format device description file.  The PostScript driver reads this to know about the scaling of fonts and so on.  The format of such files is described in groff_font(5), included with Groff.  Default: DESC.

encoding-file=ENCODING-FILE-NAME

     Sets the name of the encoding file.  This file contains a list of all font encodings that will be needed so that the driver can put all of them at the top of the prologue.  See Encodings.  Default: ps-encodings.

     If the specified encoding file cannot be found, this error will be silently ignored, since most people do not need any encodings besides the ones that can be found using auto-encodings, described below.

auto-encode=BOOLEAN

     When enabled, the font encodings needed by the default proportional- and fixed-pitch fonts will automatically be dumped to the PostScript output.  Otherwise, it is assumed that the user has an encoding file and knows how to use it (see Encodings).  There is probably no good reason to turn off this convenient feature.  Default: on.

Next I suppose it's time to describe the search algorithm.  When the PostScript driver needs a file, whether that file be a font, a PostScript prologue, or what you will, it searches in this manner:

 1. Constructs a path by taking the first of the following that is defined:

      a. Environment variable STAT_GROFF_FONT_PATH.  See Environment variables.

      b. Environment variable GROFF_FONT_PATH.

      c. The compiled-in fallback default.

 2. Constructs a base name from concatenating, in order, the font directory, a path separator (/ or \), and the file to be found.  A typical base name would be something like devps/ps-encodings.

 3. Searches for the base name in the path constructed above.  If the file is found, the algorithm terminates.

 4. Searches for the base name in the standard configuration path.  See File locations, for more details.  If the file is found, the algorithm terminates.

 5. At this point we remove the font directory and path separator from the base name.  Now the base name is simply the file to be found, i.e., ps-encodings.

 6. Searches for the base name in the path constructed in the first step. If the file is found, the algorithm terminates.

 7. Searches for the base name in the standard configuration path.  If the file is found, the algorithm terminates.

 8. The algorithm terminates unsuccessfully.

So, as you see, there are several ways to configure the PostScript drivers.  Careful selection of techniques can make the configuration very flexible indeed.

PostScript font options
-----------------------

The list of available font options is short and sweet:

prop-font=FONT-NAME

     Sets the default proportional font.  The name should be that of a PostScript font.  Default: "Helvetica".

fixed-font=FONT-NAME

     Sets the default fixed-pitch font.  The name should be that of a PostScript font.  Default: "Courier".

font-size=FONT-SIZE

     Sets the size of the default fonts, in thousandths of a point.  Default: 10000.

PostScript line options
-----------------------

Most tables contain lines, or rules, between cells.  Some features of the way that lines are drawn in PostScript tables are user-definable:

line-style=STYLE

     Sets the style used for lines used to divide tables into sections. STYLE must be either thick, in which case thick lines are used, or DOUBLE, in which case double lines are used.  Default: thick.

line-gutter=DIMENSION

     Sets the line gutter, which is the amount of whitespace on either side of lines that border text or graphics objects.  See Dimensions. Default: 0.5pt.

line-spacing=DIMENSION

     Sets the line spacing, which is the amount of whitespace that separates lines that are side by side, as in a double line.  Default: 0.5pt.

line-width=DIMENSION

     Sets the width of a typical line used in tables.  Default: 0.5pt.

line-width-thick=DIMENSION

     Sets the width of a thick line used in tables.  Not used if line-style is set to thick.  Default: 1.5pt.

The PostScript prologue
-----------------------

Most PostScript files that are generated mechanically by programs consist of two parts: a prologue and a body.  The prologue is generally a collection of boilerplate.  Only the body differs greatly between two outputs from the same program.

This is also the strategy used in the PSPP PostScript driver.  In general, the prologue supplied with PSPP will be more than sufficient. In this case, you will not need to read the rest of this section. However, hackers might want to know more.  Read on, if you fall into this category.

The prologue is dumped into the output stream essentially unmodified. However, two actions are performed on its lines.  First, certain lines may be omitted as specified in the prologue file itself.  Second, variables are substituted.

The following lines are omitted:

 1. All lines that contain three bangs in a row (!!!).

 2. Lines that contain !eps, if the PostScript driver is producing ordinary PostScript output.  Otherwise an EPS file is being produced, and the line is included in the output, although everything following !eps is deleted.

 3. Lines that contain !ps, if the PostScript driver is producing EPS output.  Otherwise, ordinary PostScript is being produced, and the line is included in the output, although everything following !ps is deleted.

The following are the variables that are substituted.  Only the variables listed are substituted; environment variables are not. See Environment substitutions.

bounding-box

     The page bounding box, in points, as four space-separated numbers.  For U.S. letter size paper, this is 0 0 612 792.

creator

     PSPP version as a string: GNU PSPP 0.1b, for example.

date

     Date the file was created.  Example: Tue May 21 13:46:22 1991.

data

     Value of the data PostScript driver option, as one of the strings Clean7Bit, Clean8Bit, or Binary.

orientation

     Page orientation, as one of the strings Portrait or Landscape.

user

     Under multiuser OSes, the user's login name, taken either from the environment variable LOGNAME or, if that fails, the result of the C library function getlogin().  Defaults to nobody.

host

     System hostname as reported by gethostname().  Defaults to nowhere.

prop-font

     Name of the default proportional font, prefixed by the word font and a space.  Example: font Times-Roman.

fixed-font

     Name of the default fixed-pitch font, prefixed by the word font and a space.

scale-factor

     The page scaling factor as a floating-point number.  Example: 1.0.  Note that this is also passed as an argument to the BP macro.

paper-length

paper-width

     The paper length and paper width, respectively, in thousandths of a point.  Note that these are also passed as arguments to the BP macro.

left-margin

top-margin

     The left margin and top margin, respectively, in thousandths of a point.  Note that these are also passed as arguments to the BP macro.

title

     Document title as a string.  This is not the title specified in the PSPP syntax file.  A typical title is the word PSPP followed by the syntax file name in parentheses.  Example: PSPP (<stdin>).

source-file

     PSPP syntax file name.  Example: mary96/first.stat.

Any other questions about the PostScript prologue can best be answered by examining the default prologue or the PSPP source.

PostScript encodings
--------------------

PostScript fonts often contain many more than 256 characters, in order to accommodate foreign language characters and special symbols. PostScript uses encodings to map these onto single-byte symbol sets.  Each font can have many different encodings applied to it.

PSPP's PostScript driver needs to know which encoding to apply to each font.  It can determine this from the information encapsulated in the Groff font description that it reads.  However, there is an additional problem---for efficiency, the PostScript driver needs to have a complete list of all encodings that will be used in the entire session when it opens the output file.  For this reason, it can't use the information built into the fonts because it doesn't know which fonts will be used.

As a stopgap solution, there are two mechanisms for specifying which encodings will be used.  The first mechanism is automatic and it is the only one that most PSPP users will ever need.  The second mechanism is manual, but it is more flexible.  Either mechanism or both may be used at one time.

The first mechanism is activated by the auto-encode driver option (see PS file options).  When enabled, auto-encode causes the PostScript driver to include the encodings used by the default proportional and fixed-pitch fonts (see PS font options).  Many PSPP output files will only need these encodings.

The second mechanism is the file specified by the encoding-file option (see PS file options).  If it exists, this file must consist of lines in PSPP configuration-file format (see Configuration files).  Each line that is not a comment should name a PostScript encoding to include in the output.

It is not an error if an encoding is included more than once, by either mechanism.  It will appear only once in the output.  It is also not an error if an encoding is included in the output but never used.  It is an error if an encoding is used but not included by one of these mechanisms.  In this case, the built-in PostScript encoding ISOLatin1Encoding is substituted.

The ASCII driver class
======================

The ASCII driver class produces output that can be displayed on a terminal or output to printers.  All of its options are highly configurable.  The ASCII driver has class name ascii.

The ASCII driver is described in further detail below.

ASCII output options
--------------------

output-file=FILENAME

     File to which output should be sent.  This can be an ordinary filename (e.g., "pspp.txt"), a pipe filename (e.g., "|lpr"), or stdout ("-").  Default: "pspp.list".

char-set=CHAR-SET-TYPE

     One of ascii or latin1.  This has no effect on output at the present time.  Default: ascii.

form-feed-string=FORM-FEED-VALUE

     The string written to the output to cause a formfeed.  See also paginate, described below, for a related setting.  Default: "\f".

newline-string=NEW-LINE-VALUE

     The string written to the output to cause a new-line (carriage return plus linefeed).  The default, which can be specified explicitly with newline-string=default, is to use the system-dependent new-line sequence by opening the output file in text mode.  This is usually the right choice.

     However, newline-string can be set to any string.  When this is done, the output file is opened in binary mode.

paginate=BOOLEAN

     If set, a formfeed (as set in form-feed-string, described above) will be written to the device after every page.  Default: on.

tab-width=TAB-WIDTH-VALUE

     The distance between tab stops for this device.  If set to 0, tabs will not be used in the output.  Default: 8.

init=INITIALIZATION-STRING.

     String written to the device before anything else, at the beginning of the output.  Default: "" (the empty string).

done=FINALIZATION-STRING.

     String written to the device after everything else, at the end of the output.  Default: "" (the empty string).

ASCII page options
------------------

These options affect page setup:

headers=BOOLEAN

     If enabled, two lines of header information giving title and subtitle, page number, date and time, and PSPP version are printed at the top of every page.  These two lines are in addition to any top margin requested.  Default: on.

length=LINE-COUNT

     Physical length of a page, in lines.  Headers and margins are subtracted from this value.  Default: 66.

width=CHARACTER-COUNT

     Physical width of a page, in characters.  Margins are subtracted from this value.  Default: 130.

lpi=LINES-PER-INCH

     Number of lines per vertical inch.  Not currently used.  Default: 6.

cpi=CHARACTERS-PER-INCH

     Number of characters per horizontal inch.  Not currently used.  Default: 10.

left-margin=LEFT-MARGIN-WIDTH

     Width of the left margin, in characters.  PSPP subtracts this value from the page width.  Default: 0.

right-margin=RIGHT-MARGIN-WIDTH

     Width of the right margin, in characters.  PSPP subtracts this value from the page width.  Default: 0.

top-margin=TOP-MARGIN-LINES

     Length of the top margin, in lines.  PSPP subtracts this value from the page length.  Default: 2.

bottom-margin=BOTTOM-MARGIN-LINES

     Length of the bottom margin, in lines.  PSPP subtracts this value from the page length.  Default: 2.

ASCII font options
------------------

These are the ASCII font options:

box[LINE-TYPE]=BOX-CHARS

     The characters used for lines in tables produced by the ASCII driver can be changed using this option.  LINE-TYPE is used to indicate which type of line to change; BOX-CHARS is the character or string of characters to use for this type of line.

     LINE-TYPE must be a 4-digit number in base 4.  The digits are in the order `right', `bottom', `left', `top'.  The four possibilities for each digit are:

     0
          No line.

     1
          Single line.

     2
          Double line.

     3
          Special device-defined line, if one is available; otherwise, a double line.

     Examples:

     box[0101]="|"

          Sets | as the character to use for a single-width line with bottom and top components.

     box[2222]="#"

          Sets # as the character to use for the intersection of four double-width lines, one each from the top, bottom, left and right.

     box[1100]="\xda"

          Sets "\xda", which under MS-DOS is a box character suitable for the top-left corner of a box, as the character for the intersection of two single-width lines, one each from the right and bottom.

     Defaults:

       * box[0000]=" "

       * box[1000]="-"

          box[0010]="-"

          box[1010]="-"

       * box[0100]="|"

          box[0001]="|"

          box[0101]="|"

       * box[2000]="="

          box[0020]="="

          box[2020]="="

       * box[0200]="#"

          box[0002]="#"

          box[0202]="#"

       * box[3000]="="

          box[0030]="="

          box[3030]="="

       * box[0300]="#"

          box[0003]="#"

          box[0303]="#"

       * For all others, + is used unless there are double lines or special lines, in which case # is used.

italic-on=ITALIC-ON-STRING

     Character sequence written to turn on italics or underline printing.  If this is set to overstrike, then the driver will simulate underlining by overstriking with underscore characters (_) in the manner described by overstrike-style and carriage-return-style.  Default: overstrike.

italic-off=ITALIC-OFF-STRING

     Character sequence to turn off italics or underline printing.  Default: "" (the empty string).

bold-on=BOLD-ON-STRING

     Character sequence written to turn on bold or emphasized printing.  If set to overstrike, then the driver will simulated bold printing by overstriking characters in the manner described by overstrike-style and carriage-return-style.  Default: overstrike.

bold-off=BOLD-OFF-STRING

     Character sequence to turn off bold or emphasized printing.  Default: "" (the empty string).

bold-italic-on=BOLD-ITALIC-ON-STRING

     Character sequence written to turn on bold-italic printing.  If set to overstrike, then the driver will simulate bold-italics by overstriking twice, once with the character, a second time with an underscore (_) character, in the manner described by overstrike-style and carriage-return-style.  Default: overstrike.

bold-italic-off=BOLD-ITALIC-OFF-STRING

     Character sequence to turn off bold-italic printing.  Default: "" (the empty string).

overstrike-style=OVERSTRIKE-OPTION

     Either single or line:

       * If single is selected, then, to overstrike a line of text, the output driver will output a character, backspace, overstrike, output a character, backspace, overstrike, and so on along a line.

       * If line is selected then the output driver will output an entire line, then backspace or emit a carriage return (as indicated by carriage-return-style), then overstrike the entire line at once.

     single is recommended for use with ttys and programs that understand overstriking in text files, such as the pager less. single will also work with printer devices but results in rapid back-and-forth motions of the printhead that can cause the printer to physically overheat!

     line is recommended for use with printer devices.  Most programs that understand overstriking in text files will not properly deal with line mode.

     Default: single.

carriage-return-style=CARRIAGE-RETURN-TYPE

     Either bs or cr.  This option applies only when one or more of the font commands is set to overstrike and, at the same time, overstrike-style is set to line.

       * If bs is selected then the driver will return to the beginning of a line by emitting a sequence of backspace characters (ASCII 8).

       * If cr is selected then the driver will return to the beginning of a line by emitting a single carriage-return character (ASCII 13).

     Although cr is preferred as being more compact, bs is more general since some devices do not interpret carriage returns in the desired manner.  Default: bs.

The HTML driver class
=====================

The html driver class is used to produce output for viewing in tables-capable web browsers such as Emacs' w3-mode.  Its configuration is very simple.  Currently, the output has a very plain format.  In the future, further work may be done on improving the output appearance.

There are few options for use with the html driver class:

output-file=FILENAME

     File to which output should be sent.  This can be an ordinary filename (i.e., "pspp.ps"), a pipe filename (i.e., "|lpr"), or stdout ("-").  Default: "pspp.html".

prologue-file=PROLOGUE-FILE-NAME

     Sets the name of the PostScript prologue file.  You can write your own prologue if you want to customize colors or other settings: see HTML Prologue.  Default: html-prologue.

The HTML prologue
-----------------

HTML files that are generated by PSPP consist of two parts: a prologue and a body.  The prologue is a collection of boilerplate.  Only the body differs greatly between two outputs.  You can tune the colors and other attributes of the output by editing the prologue.

The prologue is dumped into the output stream essentially unmodified. However, two actions are performed on its lines.  First, certain lines may be omitted as specified in the prologue file itself.  Second, variables are substituted.

The following lines are omitted:

 1. All lines that contain three bangs in a row (!!!).

 2. Lines that contain !title, if no title is set for the output.  If a title is set, then the characters !title are removed before the line is output.

 3. Lines that contain !subtitle, if no subtitle is set for the output.  If a subtitle is set, then the characters !subtitle are removed before the line is output.

The following are the variables that are substituted.  Only the variables listed are substituted; environment variables are not. See Environment substitutions.

generator

     PSPP version as a string: GNU PSPP 0.1b, for example.

date

     Date the file was created.  Example: Tue May 21 13:46:22 1991.

user

     Under multiuser OSes, the user's login name, taken either from the environment variable LOGNAME or, if that fails, the result of the C library function getlogin().  Defaults to nobody.

host

     System hostname as reported by gethostname().  Defaults to nowhere.

title

     Document title as a string.  This is the title specified in the PSPP syntax file.

subtitle

     Document subtitle as a string.

source-file

     PSPP syntax file name.  Example: mary96/first.stat.

Miscellaneous configuration
===========================

The following environment variables can be used to further configure PSPP:

HOME

     Used to determine the user's home directory.  No default value.

STAT_INCLUDE_PATH

     Path used to find include files in PSPP syntax files.  Defaults vary across operating systems:

     UNIX

            * .

            * ~/.pspp/include

            * /usr/local/lib/pspp/include

            * /usr/lib/pspp/include

            * /usr/local/share/pspp/include

            * /usr/share/pspp/include

     MS-DOS

            * .

            * C:\PSPP\INCLUDE

            * $PATH

     Other OSes
          No default path.

STAT_PAGER
PAGER

     When PSPP invokes an external pager, it uses the first of these that is defined.  There is a default pager only if the person who compiled PSPP defined one.

TERM

     The terminal type termcap or ncurses will use, if such support was compiled into PSPP.

STAT_OUTPUT_INIT_FILE

     The basename used to search for the driver definition file. See Output devices.  See File locations.  Default: devices.

STAT_OUTPUT_PAPERSIZE_FILE

     The basename used to search for the papersize file.  See papersize. See File locations.  Default: papersize.

STAT_OUTPUT_INIT_PATH

     The path used to search for the driver definition file and the papersize file.  See File locations.  Default: the standard configuration path.

TMPDIR

     The directory in which PSPP stores its temporary files (used when sorting cases or concatenating large numbers of cases). Default: (UNIX) /tmp, (MS-DOS) \, (other OSes) empty string.

TEMP

TMP

     Under MS-DOS only, these variables are consulted after TMPDIR, in this order.

Improving output quality
========================

When its drivers are set up properly, PSPP can produce output that looks very good indeed.  The PostScript driver, suitably configured, can produce presentation-quality output.  Here are a few guidelines for producing better-looking output, regardless of output driver.  Your mileage may vary, of course, and everyone has different esthetic preferences.

  * Width is important in PSPP output.  Greater output width leads to more readable output, to a point.  Try the following to increase the output width:

       - If you're using the ASCII driver with a dot-matrix printer, figure out what you need to do to put the printer into compressed mode.  Put that string into the init-string setting.  Try to get 132 columns; 160 might be better, but you might find that print that tiny is difficult to read.

       - With the PostScript driver, try these ideas:

            + Landscape mode.

            + Legal-size (8.5" x 14") paper in landscape mode.

            + Reducing font sizes.  If you're using 12-point fonts, try 10 point; if you're using 10-point fonts, try 8 point.  Some fonts are more readable than others at small sizes.

     Try to strike a balance between character size and page width.

  * Use high-quality fonts.  Many public domain fonts are poor in quality. Recently, URW made some high-quality fonts available under the GPL. These are probably suitable.

  * Be sure you're using the proper font metrics.  The font metrics provided with PSPP may not correspond to the fonts actually being printed. This can cause bizarre-looking output.

  * Make sure that you're using good ink/ribbon/toner.  Darker print is easier to read.

  * Use plain fonts with serifs, such as Times-Roman or Palatino.  Avoid choosing italic or bold fonts as document base fonts.