Add support for reading and writing SPV files.

[pspp] / doc / utilities.texi

@c PSPP - a program for statistical analysis.
@c Copyright (C) 2017 Free Software Foundation, Inc.
@c Permission is granted to copy, distribute and/or modify this document
@c under the terms of the GNU Free Documentation License, Version 1.3
@c or any later version published by the Free Software Foundation;
@c with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.
@c A copy of the license is included in the section entitled "GNU
@c Free Documentation License".
@c
@node Utilities
@chapter Utilities

Commands that don't fit any other category are placed here.

Most of these commands are not affected by commands like @cmd{IF} and
@cmd{LOOP}:
they take effect only once, unconditionally, at the time that they are
encountered in the input.

@menu
* ADD DOCUMENT::                Add documentary text to the active dataset.
* CACHE::                       Ignored for compatibility.
* CD::                          Change the current directory.
* COMMENT::                     Document your syntax file.
* DOCUMENT::                    Document the active dataset.
* DISPLAY DOCUMENTS::           Display active dataset documents.
* DISPLAY FILE LABEL::          Display the active dataset label.
* DROP DOCUMENTS::              Remove documents from the active dataset.
* ECHO::                        Write a string to the output stream.
* ERASE::                       Erase a file.
* EXECUTE::                     Execute pending transformations.
* FILE LABEL::                  Set the active dataset's label.
* FINISH::                      Terminate the @pspp{} session.
* HOST::                        Temporarily return to the operating system.
* INCLUDE::                     Include a file within the current one.
* INSERT::                      Insert a file within the current one.
* OUTPUT::                      Modify the appearance of the output.
* PERMISSIONS::                 Change permissions on a file.
* PRESERVE and RESTORE::        Saving settings and restoring them later.
* SET::                         Adjust @pspp{} runtime parameters.
* SHOW::                        Display runtime parameters.
* SUBTITLE::                    Provide a document subtitle.
* TITLE::                       Provide a document title.
@end menu

@node ADD DOCUMENT
@section ADD DOCUMENT
@vindex  ADD DOCUMENT

@display
ADD DOCUMENT 
    'line one' 'line two' @dots{} 'last line' .
@end display


@cmd{ADD DOCUMENT} adds one or more lines of descriptive commentary to 
the active dataset.  Documents added in this way are saved to system files.
They can be viewed using @cmd{SYSFILE INFO} or @cmd{DISPLAY
DOCUMENTS}.  They can be removed from the active dataset with @cmd{DROP
DOCUMENTS}.

Each line of documentary text must be enclosed in quotation marks, and 
may not be more than 80 bytes long. @xref{DOCUMENT}.

@node CACHE
@section CACHE
@vindex CACHE

@display
CACHE.
@end display

This command is accepted, for compatibility, but it has no effect.

@node CD
@section CD
@vindex CD
@cindex directory
@cindex changing directory

@display
CD 'new directory' .
@end display 

@cmd{CD} changes the current directory.  The new directory will become that specified by the command.

@node COMMENT
@section COMMENT
@vindex COMMENT
@vindex *

@display 
Two possibles syntaxes:
        COMMENT comment text @dots{} .
        *comment text @dots{} .
@end display

@cmd{COMMENT} is ignored.  It is used to provide information to
the author and other readers of the @pspp{} syntax file.  

@cmd{COMMENT} can extend over any number of lines.  Don't forget to
terminate it with a dot or a blank line.



@node DOCUMENT
@section DOCUMENT
@vindex DOCUMENT

@display
DOCUMENT @var{documentary_text}.
@end display

@cmd{DOCUMENT} adds one or more lines of descriptive commentary to the
active dataset.  Documents added in this way are saved to system files.
They can be viewed using @cmd{SYSFILE INFO} or @cmd{DISPLAY
DOCUMENTS}.  They can be removed from the active dataset with @cmd{DROP
DOCUMENTS}.

Specify the @var{documentary text} following the @subcmd{DOCUMENT} keyword.  
It is interpreted literally --- any quotes or other punctuation marks 
will be included in the file.
You can extend the documentary text over as many lines as necessary.  
Lines are truncated at 80 bytes.  Don't forget to terminate
the command with a dot or a blank line. @xref{ADD DOCUMENT}.

@node DISPLAY DOCUMENTS
@section DISPLAY DOCUMENTS
@vindex DISPLAY DOCUMENTS

@display
DISPLAY DOCUMENTS.
@end display

@cmd{DISPLAY DOCUMENTS} displays the documents in the active dataset.  Each
document is preceded by a line giving the time and date that it was
added.  @xref{DOCUMENT}.

@node DISPLAY FILE LABEL
@section DISPLAY FILE LABEL
@vindex DISPLAY FILE LABEL

@display
DISPLAY FILE LABEL.
@end display

@cmd{DISPLAY FILE LABEL} displays the file label contained in the
active dataset,
if any.  @xref{FILE LABEL}.

This command is a @pspp{} extension.

@node DROP DOCUMENTS
@section DROP DOCUMENTS
@vindex DROP DOCUMENTS

@display
DROP DOCUMENTS.
@end display

@cmd{DROP DOCUMENTS} removes all documents from the active dataset.
New documents can be added with @cmd{DOCUMENT} (@pxref{DOCUMENT}).

@cmd{DROP DOCUMENTS} changes only the active dataset.  It does not modify any
system files stored on disk.

@node ECHO
@section ECHO
@vindex ECHO

@display 
ECHO 'arbitrary text' .
@end display

Use @cmd{ECHO} to write arbitrary text to the output stream. The text should be enclosed in quotation marks following the normal rules for string tokens (@pxref{Tokens}).

@node ERASE
@section ERASE
@vindex ERASE

@display
ERASE FILE @var{file_name}.
@end display

@cmd{ERASE FILE} deletes a file from the local filesystem.
@var{file_name} must be quoted.
This command cannot be used if the SAFER (@pxref{SET}) setting is active.


@node EXECUTE
@section EXECUTE
@vindex EXECUTE

@display
EXECUTE.
@end display

@cmd{EXECUTE} causes the active dataset to be read and all pending
transformations to be executed.

@node FILE LABEL
@section FILE LABEL
@vindex FILE LABEL

@display
FILE LABEL @var{file_label}.
@end display

@cmd{FILE LABEL} provides a title for the active dataset.  This
title will be saved into system files and portable files that are
created during this @pspp{} run.

@var{file_label} should not be quoted.
If quotes are included, they are literally interpreted and become part of the file label.

@node FINISH
@section FINISH
@vindex FINISH

@display
FINISH.
@end display

@cmd{FINISH} terminates the current @pspp{} session and returns
control to the operating system.

@node HOST
@section HOST
@vindex HOST

@display
HOST.
HOST COMMAND=['@var{command}'...].
@end display

@cmd{HOST} suspends the current @pspp{} session and temporarily returns control 
to the operating system.
This command cannot be used if the SAFER (@pxref{SET}) setting is active.

If the @subcmd{COMMAND} subcommand is specified, as a sequence of shell
commands as quoted strings within square brackets, then @pspp{} executes
them together in a single subshell.

If no subcommands are specified, then @pspp{} invokes an interactive
subshell.

@node INCLUDE
@section INCLUDE
@vindex INCLUDE

@display
        INCLUDE [FILE=]'@var{file_name}' [ENCODING='@var{encoding}'].
@end display

@cmd{INCLUDE} causes the @pspp{} command processor to read an
additional command file as if it were included bodily in the current
command file.
If errors are encountered in the included file, then command processing will 
stop and no more commands will be processed.
Include files may be nested to any depth, up to the limit of available
memory.

The @cmd{INSERT} command (@pxref{INSERT}) is a more flexible
alternative to @cmd{INCLUDE}.  An @cmd{INCLUDE} command acts the same as
@cmd{INSERT} with @subcmd{ERROR=STOP CD=NO SYNTAX=BATCH} specified.

The optional @subcmd{ENCODING} subcommand has the same meaning as with @cmd{INSERT}.

@node INSERT
@section INSERT
@vindex INSERT

@display
     INSERT [FILE=]'@var{file_name}'
        [CD=@{NO,YES@}]
        [ERROR=@{CONTINUE,STOP@}]
        [SYNTAX=@{BATCH,INTERACTIVE@}]
        [ENCODING=@{LOCALE, '@var{charset_name}'@}].
@end display

@cmd{INSERT} is similar to @cmd{INCLUDE} (@pxref{INCLUDE}) 
but somewhat more flexible.
It causes the command processor to read a file as if it were embedded in the 
current command file.

If @subcmd{CD=YES} is specified, then before including the file, the
current directory  will be changed to the directory of the included
file.  
The default setting is @samp{CD=NO}.
Note that this directory will remain current until it is
changed explicitly (with the @cmd{CD} command, or a subsequent
@cmd{INSERT} command with the @samp{CD=YES} option).
It will not revert to its original setting even after the included
file is finished processing.

If @subcmd{ERROR=STOP} is specified, errors encountered in the
inserted file will cause processing to immediately cease.
Otherwise processing will continue at the next command.
The default setting is @subcmd{ERROR=CONTINUE}.

If @subcmd{SYNTAX=INTERACTIVE} is specified then the syntax contained in
the included file must conform to interactive syntax
conventions. @xref{Syntax Variants}.
The default setting is @subcmd{SYNTAX=BATCH}.

@subcmd{ENCODING} optionally specifies the character set used by the included
file.  Its argument, which is not case-sensitive, must be in one of
the following forms:

@table @asis
@item @subcmd{LOCALE}
The encoding used by the system locale, or as overridden by the 
@cmd{SET} command (@pxref{SET}).  On GNU/Linux and other Unix-like systems,
environment variables, e.g.@: @env{LANG} or @env{LC_ALL}, determine the
system locale.

@item @var{charset_name}
One of the character set names listed by @acronym{IANA} at
@uref{http://www.iana.org/assignments/character-sets}.  Some examples
are @code{ASCII} (United States), @code{ISO-8859-1} (western Europe),
@code{EUC-JP} (Japan), and @code{windows-1252} (Windows).  Not all
systems support all character sets.

@item @code{Auto,@var{encoding}}
Automatically detects whether a syntax file is encoded in an Unicode
encoding such as UTF-8, UTF-16, or UTF-32.  If it is not, then @pspp{}
generally assumes that the file is encoded in @var{encoding} (an @acronym{IANA}
character set name).  However, if @var{encoding} is UTF-8, and the
syntax file is not valid UTF-8, @pspp{} instead assumes that the file
is encoded in @code{windows-1252}.

For best results, @var{encoding} should be an @acronym{ASCII}-compatible
encoding (the most common locale encodings are all @acronym{ASCII}-compatible),
because encodings that are not @acronym{ASCII} compatible cannot be
automatically distinguished from UTF-8.

@item @code{Auto}
@item @code{Auto,Locale}
Automatic detection, as above, with the default encoding taken from
the system locale or the setting on @subcmd{SET LOCALE}.
@end table

When ENCODING is not specified, the default is taken from the
@option{--syntax-encoding} command option, if it was specified, and
otherwise it is @code{Auto}.

@node OUTPUT
@section OUTPUT
@vindex OUTPUT
@cindex precision, of output
@cindex decimal places

@display
OUTPUT MODIFY
       /SELECT TABLES
       /TABLECELLS SELECT = [ @var{class}... ]
                   FORMAT = @var{fmt_spec}.
@end display
@note{In the above synopsis the characters @samp{[} and @samp{]} are literals.
They must appear in the syntax to be interpreted.}

@cmd{OUTPUT} changes the appearance of the tables in which results are printed.
In particular, it can be used to set the format and precision to which results are displayed.

After running this command, the default table appearance parameters will have been modified and  each 
new output table generated will use the new parameters.

Following @code{/TABLECELLS SELECT =} a list of cell classes must appear, enclosed in square
brackets.  This list determines the classes of values should be selected for modification.
Each class can be:

@table @asis
@item RESIDUAL
Residual values.  Default: @t{F40.2}.

@item CORRELATION
Correlations.  Default: @t{F40.3}.

@item PERCENT
Percentages.  Default: @t{PCT40.1}.

@item SIGNIFICANCE
Significance of tests (p-values).  Default: @t{F40.3}.

@item COUNT
Counts or sums of weights.  For a weighted data set, the default is
the weight variable's print format.  For an unweighted data set, the
default is F40.0.
@end table

For most other numeric values that appear in tables, @code{SET FORMAT}
may be used to specify the format (@pxref{SET FORMAT}).

The value of @var{fmt_spec} must be a valid output format (@pxref{Input and Output Formats}).
Note that not all possible formats are meaningful for all classes.

@node PERMISSIONS
@section PERMISSIONS
@vindex PERMISSIONS
@cindex mode
@cindex file mode
@cindex changing file permissions

@display
PERMISSIONS
        FILE='@var{file_name}'
        /PERMISSIONS = @{READONLY,WRITEABLE@}.
@end display

@cmd{PERMISSIONS} changes the permissions of a file.  
There is one mandatory subcommand which specifies the permissions to
which the file should be changed.  
If you set a file's  permission  to @subcmd{READONLY}, then the file will become
unwritable either by you or anyone else on the system.
If you set the permission to @subcmd{WRITEABLE}, then the file will become
writeable by you; the permissions afforded to others will be
unchanged.
This command cannot be used if the @subcmd{SAFER} (@pxref{SET}) setting is active.


@node PRESERVE and RESTORE
@section PRESERVE and RESTORE
@vindex PRESERVE
@vindex RESTORE

@display
PRESERVE.
@dots{}
RESTORE.
@end display

@cmd{PRESERVE} saves all of the settings that @cmd{SET} (@pxref{SET})
can adjust.  A later @cmd{RESTORE} command restores those settings.

@cmd{PRESERVE} can be nested up to five levels deep.

@node SET
@section SET
@vindex SET

@display
SET

(data input)
        /BLANKS=@{SYSMIS,'.',number@}
        /DECIMAL=@{DOT,COMMA@}
        /FORMAT=@var{fmt_spec}
        /EPOCH=@{AUTOMATIC,@var{year}@}
        /RIB=@{NATIVE,MSBFIRST,LSBFIRST,VAX@}
        /RRB=@{NATIVE,ISL,ISB,IDL,IDB,VF,VD,VG,ZS,ZL@}

(interaction)
        /MXERRS=@var{max_errs}
        /MXWARNS=@var{max_warnings}
        /WORKSPACE=@var{workspace_size}

(syntax execution)
        /LOCALE='@var{locale}'
        /MEXPAND=@{ON,OFF@}
        /MITERATE=@var{max_iterations}
        /MNEST=@var{max_nest}
        /MPRINT=@{ON,OFF@}
        /MXLOOPS=@var{max_loops}
        /SEED=@{RANDOM,@var{seed_value}@}
        /UNDEFINED=@{WARN,NOWARN@}
        /FUZZBITS=@var{fuzzbits}

(data output)
        /CC@{A,B,C,D,E@}=@{'@var{npre},@var{pre},@var{suf},@var{nsuf}','@var{npre}.@var{pre}.@var{suf}.@var{nsuf}'@}
        /DECIMAL=@{DOT,COMMA@}
        /FORMAT=@var{fmt_spec}
        /WIB=@{NATIVE,MSBFIRST,LSBFIRST,VAX@}
        /WRB=@{NATIVE,ISL,ISB,IDL,IDB,VF,VD,VG,ZS,ZL@}

(output routing)
        /ERRORS=@{ON,OFF,TERMINAL,LISTING,BOTH,NONE@}
        /MESSAGES=@{ON,OFF,TERMINAL,LISTING,BOTH,NONE@}
        /PRINTBACK=@{ON,OFF,TERMINAL,LISTING,BOTH,NONE@}
        /RESULTS=@{ON,OFF,TERMINAL,LISTING,BOTH,NONE@}

(output driver options)
        /HEADERS=@{NO,YES,BLANK@}
        /LENGTH=@{NONE,@var{n_lines}@}
        /MORE=@{ON,OFF@}
        /WIDTH=@{NARROW,WIDTH,@var{n_characters}@}
        /TNUMBERS=@{VALUES,LABELS,BOTH@}
        /TVARS=@{NAMES,LABELS,BOTH@}

(logging)
        /JOURNAL=@{ON,OFF@} ['@var{file_name}']

(system files)
        /COMPRESSION=@{ON,OFF@}
        /SCOMPRESSION=@{ON,OFF@}

(miscellaneous)
        /SAFER=ON
        /LOCALE='@var{string}'


(obsolete settings accepted for compatibility, but ignored)
        /BOXSTRING=@{'@var{xxx}','@var{xxxxxxxxxxx}'@}
        /CASE=@{UPPER,UPLOW@}
        /CPI=cpi_value
        /HIGHRES=@{ON,OFF@}
        /HISTOGRAM='@var{c}'
        /LOWRES=@{AUTO,ON,OFF@}
        /LPI=@var{lpi_value}
        /MENUS=@{STANDARD,EXTENDED@}
        /MXMEMORY=@var{max_memory}
        /SCRIPTTAB='c'
        /TB1=@{'@var{xxx}','@var{xxxxxxxxxxx}'@}
        /TBFONTS='@var{string}'
        /XSORT=@{YES,NO@}
@end display

@cmd{SET} allows the user to adjust several parameters relating to
@pspp{}'s execution.  Since there are many subcommands to this command, its
subcommands will be examined in groups.

For subcommands that take boolean values, @subcmd{ON} and @subcmd{YES} are synonymous, 
as are @subcmd{OFF} and @subcmd{NO}, when used as subcommand values.

The data input subcommands affect the way that data is read from data
files.  The data input subcommands are

@table @asis
@item BLANKS
@anchor{SET BLANKS}
This is the value assigned to an item data item that is empty or
contains only white space.  An argument of SYSMIS or '.' will cause the
system-missing value to be assigned to null items.  This is the
default.  Any real value may be assigned.

@item DECIMAL
@anchor{SET DECIMAL}
This value may be set to @subcmd{DOT} or @subcmd{COMMA}.
Setting it to @subcmd{DOT} causes the decimal point character to be
@samp{.} and the grouping character to be @samp{,}.
Setting it to @subcmd{COMMA}
causes the decimal point character to be @samp{,} and the grouping
character to be @samp{.}.
If the setting is @subcmd{COMMA}, then @samp{,} will not be treated
as a field separator in the @cmd{DATA LIST} command (@pxref{DATA LIST}).
The default value is determined from the system locale.

@item FORMAT
@anchor{SET FORMAT}
Allows the default numeric input/output format to be specified.  The
default is F8.2.  @xref{Input and Output Formats}.

@item EPOCH
@anchor{SET EPOCH}
Specifies the range of years used when a 2-digit year is read from a
data file or used in a date construction expression (@pxref{Date
Construction}).  If a 4-digit year is specified for the epoch, then
2-digit years are interpreted starting from that year, known as the
epoch.  If @subcmd{AUTOMATIC} (the default) is specified, then the epoch begins
69 years before the current date.

@item RIB
@anchor{SET RIB} 

@pspp{} extension to set the byte ordering (endianness) used for reading
data in IB or PIB format (@pxref{Binary and Hexadecimal Numeric
Formats}).  In @subcmd{MSBFIRST} ordering, the most-significant byte appears at
the left end of a IB or PIB field.  In @subcmd{LSBFIRST} ordering, the
least-significant byte appears at the left end.  @subcmd{VAX} ordering is like
@subcmd{MSBFIRST}, except that each pair of bytes is in reverse order.  @subcmd{NATIVE},
the default, is equivalent to @subcmd{MSBFIRST} or @subcmd{LSBFIRST} depending on the
native format of the machine running @pspp{}.

@item RRB
@anchor{SET RRB}

@pspp{} extension to set the floating-point format used for reading data in
RB format (@pxref{Binary and Hexadecimal Numeric Formats}).  The
possibilities are:

@table @asis
@item NATIVE
The native format of the machine running @pspp{}.  Equivalent to either IDL
or IDB.

@item ISL
32-bit IEEE 754 single-precision floating point, in little-endian byte
order.

@item ISB
32-bit IEEE 754 single-precision floating point, in big-endian byte
order.

@item IDL
64-bit IEEE 754 double-precision floating point, in little-endian byte
order.

@item IDB
64-bit IEEE 754 double-precision floating point, in big-endian byte
order.

@item VF
32-bit VAX F format, in VAX-endian byte order.

@item VD
64-bit VAX D format, in VAX-endian byte order.

@item VG
64-bit VAX G format, in VAX-endian byte order.

@item ZS
32-bit IBM Z architecture short format hexadecimal floating point, in
big-endian byte order.  

@item ZL
64-bit IBM Z architecture long format hexadecimal floating point, in
big-endian byte order.

Z architecture also supports IEEE 754 floating point.  The ZS and ZL
formats are only for use with very old input files.
@end table
The default is NATIVE.
@end table

Interaction subcommands affect the way that @pspp{} interacts with an
online user.  The interaction subcommands are

@table @asis
@item MXERRS
The maximum number of errors before @pspp{} halts processing of the current
command file.  The default is 50.

@item MXWARNS
The maximum number of warnings + errors before @pspp{} halts processing the
current command file.  
The special value of zero means that all warning situations should be ignored.
No warnings will be issued, except a single initial warning advising the user
that warnings will not be given.
The default value is 100.
@end table

Syntax execution subcommands control the way that @pspp{} commands
execute.  The syntax execution subcommands are

@table @asis
@item LOCALE
Overrides the system locale for the purpose of reading and writing
syntax and data files.  The argument should be a locale name in the
general form @code{@var{language}_@var{country}.@var{encoding}}, where @var{language}
and @var{country} are 2-character language and country abbreviations,
respectively, and @var{encoding} is an @acronym{IANA} character set name.
Example locales are @code{en_US.UTF-8} (UTF-8 encoded English as
spoken in the United States) and @code{ja_JP.EUC-JP} (EUC-JP encoded
Japanese as spoken in Japan).

@item MEXPAND
@itemx MITERATE
@itemx MNEST
@itemx MPRINT
Currently not used.

@item MXLOOPS
The maximum number of iterations for an uncontrolled loop (@pxref{LOOP}).
The default @var{max_loops} is 40.

@item SEED
The initial pseudo-random number seed.  Set to a real number or to
RANDOM, which will obtain an initial seed from the current time of day.

@item UNDEFINED
Currently not used.

@item FUZZBITS
@anchor{SET FUZZBITS}
The maximum number of bits of errors in the least-significant places
to accept for rounding up a value that is almost halfway between two
possibilities for rounding with the RND operator (@pxref{Miscellaneous
Mathematics}).  The default @var{fuzzbits} is 6.

@item WORKSPACE
The maximum amount of memory (in kilobytes) that @pspp{} will use to store data being processed.
If memory in excess of the workspace size is required, then @pspp{} will start
to use temporary files to store the data.
Setting a higher value will, in general, mean procedures will run faster, 
but may cause other applications to run slower.
On platforms without virtual memory management, setting a very large workspace
may cause @pspp{} to abort.
@cindex workspace
@cindex memory, amount used to store cases
@end table

Data output subcommands affect the format of output data.  These
subcommands are

@table @asis
@item CCA
@itemx CCB
@itemx CCC
@itemx CCD
@itemx CCE
@anchor{CCx Settings}

Set up custom currency formats.  @xref{Custom Currency Formats}, for
details.

@item DECIMAL
The default @subcmd{DOT} setting causes the decimal point character to be
@samp{.}.  A setting of @subcmd{COMMA} causes the decimal point character to be
@samp{,}.

@item FORMAT
Allows the default numeric input/output format to be specified.  The
default is F8.2.  @xref{Input and Output Formats}.

@item WIB
@anchor{SET WIB} 

@pspp{} extension to set the byte ordering (endianness) used for writing
data in IB or PIB format (@pxref{Binary and Hexadecimal Numeric
Formats}).  In @subcmd{MSBFIRST} ordering, the most-significant byte appears at
the left end of a IB or PIB field.  In @subcmd{LSBFIRST} ordering, the
least-significant byte appears at the left end.  @subcmd{VAX} ordering is like
@subcmd{MSBFIRST}, except that each pair of bytes is in reverse order.  @subcmd{NATIVE},
the default, is equivalent to @subcmd{MSBFIRST} or @subcmd{LSBFIRST} depending on the
native format of the machine running @pspp{}.

@item WRB
@anchor{SET WRB}

@pspp{} extension to set the floating-point format used for writing data in
RB format (@pxref{Binary and Hexadecimal Numeric Formats}).  The choices
are the same as @subcmd{SET RIB}.  The default is @subcmd{NATIVE}.
@end table

In the @pspp{} text-based interface, the output routing subcommands
affect where output is sent.  The following values are allowed for
each of these subcommands:

@table @asis
@item OFF
@item NONE
Discard this kind of output.

@item TERMINAL
Write this output to the terminal, but not to listing files and other
output devices.

@item LISTING
Write this output to listing files and other output devices, but not
to the terminal.

@item ON
@itemx BOTH
Write this type of output to all output devices.
@end table

These output routing subcommands are:

@table @asis
@item ERRORS
Applies to error and warning messages.  The default is @subcmd{BOTH}.

@item MESSAGES
Applies to notes.  The default is @subcmd{BOTH}.

@item PRINTBACK
Determines whether the syntax used for input is printed back as part
of the output.  The default is @subcmd{NONE}.

@item RESULTS
Applies to everything not in one of the above categories, such as the
results of statistical procedures.  The default is @subcmd{BOTH}.
@end table

These subcommands have no effect on output in the @pspp{} GUI
environment.

Output driver option subcommands affect output drivers' settings.  These
subcommands are

@table @asis
@item HEADERS
@itemx LENGTH
@itemx MORE
@itemx WIDTH
@itemx TNUMBERS
The @subcmd{TNUMBERS} option sets the way in which values are displayed in output tables.
The valid settings are @subcmd{VALUES}, @subcmd{LABELS} and @subcmd{BOTH}.
If @subcmd{TNUMBERS} is set to @subcmd{VALUES}, then all values are displayed with their literal value 
(which for a numeric value is a number and for a string value an alphanumeric string).
If @subcmd{TNUMBERS} is set to @subcmd{LABELS}, then values are displayed using their assigned labels if any.
(@xref{VALUE LABELS}.)
If the a value has no label, then it will be displayed using its literal value.
If @subcmd{TNUMBERS} is set to @subcmd{BOTH}, then values will be displayed with both their label
(if any) and their literal value in parentheses.
@item TVARS
The @subcmd{TVARS} option sets the way in which variables are displayed in output tables.
The valid settings are @subcmd{NAMES}, @subcmd{LABELS} and @subcmd{BOTH}.
If @subcmd{TVARS} is set to @subcmd{NAMES}, then all variables are displayed using their names.
If @subcmd{TVARS} is set to @subcmd{LABELS}, then variables are displayed using their label if one
has been set.  If no label has been set, then the name will be used.
(@xref{VARIABLE LABELS}.)
If @subcmd{TVARS} is set to @subcmd{BOTH}, then variables will be displayed with both their label
(if any) and their name in parentheses.
@end table

@cindex headers
@cindex length
@cindex more
@cindex pager 
@cindex width
@cindex tnumbers


Logging subcommands affect logging of commands executed to external
files.  These subcommands are

@table @asis
@item JOURNAL
@itemx LOG
These subcommands, which are synonyms, control the journal.  The
default is @subcmd{ON}, which causes commands entered interactively to be
written to the journal file.  Commands included from syntax files that
are included interactively and error messages printed by @pspp{} are also
written to the journal file, prefixed by @samp{>}.  @subcmd{OFF} disables use
of the journal.

The journal is named @file{pspp.jnl} by default.  A different name may
be specified.
@end table

System file subcommands affect the default format of system files
produced by @pspp{}.  These subcommands are

@table @asis
@item COMPRESSION
Not currently used.

@item SCOMPRESSION
Whether system files created by @cmd{SAVE} or @cmd{XSAVE} are
compressed by default.  The default is @subcmd{ON}.
@end table

Security subcommands affect the operations that commands are allowed to
perform.  The security subcommands are

@table @asis
@item SAFER
Setting this option disables the following operations:

@itemize @bullet
@item
The @cmd{ERASE} command.
@item
The @cmd{HOST} command.
@item
The @cmd{PERMISSIONS} command.
@item
Pipes (file names beginning or ending with @samp{|}).
@end itemize

Be aware that this setting does not guarantee safety (commands can still
overwrite files, for instance) but it is an improvement.
When set, this setting cannot be reset during the same session, for
obvious security reasons.

@item LOCALE
@cindex locale
@cindex encoding, characters
This item is used to set the default character encoding.
The encoding may be specified either as an encoding name or alias
(see @url{http://www.iana.org/assignments/character-sets}), or
as a locale name.
If given as a locale name, only the character encoding of the 
locale is relevant.

System files written by @pspp{} will use this encoding.
System files read by @pspp{}, for which the encoding is unknown, will be
interpreted using this encoding.

The full list of valid encodings and locale names/alias are operating system
dependent.
The following are all examples of acceptable syntax on common GNU/Linux
systems.
@example
SET LOCALE='iso-8859-1'.

SET LOCALE='ru_RU.cp1251'.

SET LOCALE='japanese'.
@end example

Contrary to intuition, this command does not affect any aspect 
of the system's locale.
@end table

@node SHOW
@section SHOW
@vindex SHOW

@display
SHOW
        [ALL]
        [BLANKS]
        [CC]
        [CCA]
        [CCB]
        [CCC]
        [CCD]
        [CCE]
        [COPYING]
        [DECIMALS]
        [DIRECTORY]
        [ENVIRONMENT]
        [FORMAT]
        [FUZZBITS]
        [LENGTH]
        [MXERRS]
        [MXLOOPS]
        [MXWARNS]
        [N]
        [SCOMPRESSION]
        [TEMPDIR]
        [UNDEFINED]
        [VERSION]
        [WARRANTY]
        [WEIGHT]
        [WIDTH]
@end display

@cmd{SHOW} can be used to display the current state of @pspp{}'s execution
parameters.  Parameters that can be changed using @cmd{SET}
(@pxref{SET}), can be examined using @cmd{SHOW} using the subcommand
with the same name.  @cmd{SHOW} supports the following additional
subcommands:

@table @asis
@item @subcmd{ALL}
Show all settings.
@item @subcmd{CC}
Show all custom currency settings (@subcmd{CCA} through @subcmd{CCE}).
@item @subcmd{DIRECTORY}
Shows the current working directory.
@item @subcmd{ENVIRONMENT}
Shows the operating system details.
@item @subcmd{N}
Reports the number of cases in the active dataset.  The reported number is not
weighted.  If no dataset is defined, then @samp{Unknown} will be reported.
@item @subcmd{TEMPDIR}
Shows the path of the directory where temporary files will be stored.
@item @subcmd{VERSION}
Shows the version of this installation of @pspp{}.
@item @subcmd{WARRANTY}
Show details of the lack of warranty for @pspp{}.
@item @subcmd{COPYING} / @subcmd{LICENSE}
Display the terms of @pspp{}'s copyright licence (@pxref{License}).
@end table

Specifying @cmd{SHOW} without any subcommands is equivalent to @subcmd{SHOW ALL}.

@node SUBTITLE
@section SUBTITLE
@vindex SUBTITLE

@display
SUBTITLE '@var{subtitle_string}'.
  or
SUBTITLE @var{subtitle_string}.
@end display

@cmd{SUBTITLE} provides a subtitle to a particular @pspp{}
run.  This subtitle appears at the top of each output page below the
title, if headers are enabled on the output device.

Specify a subtitle as a string in quotes.  The alternate syntax that did
not require quotes is now obsolete.  If it is used then the subtitle is
converted to all uppercase.

@node TITLE
@section TITLE
@vindex TITLE

@display
TITLE '@var{title_string}'.
  or
TITLE @var{title_string}.
@end display

@cmd{TITLE} provides a title to a particular @pspp{} run.
This title appears at the top of each output page, if headers are enabled
on the output device.

Specify a title as a string in quotes.  The alternate syntax that did
not require quotes is now obsolete.  If it is used then the title is
converted to all uppercase.