-@node System and Portable Files
-@chapter System Files and Portable Files
+@node System and Portable File IO
+@chapter System and Portable File I/O
The commands in this chapter read, write, and examine system files and
portable files.
* APPLY DICTIONARY:: Apply system file dictionary to active file.
* EXPORT:: Write to a portable file.
* GET:: Read from a system file.
+* GET DATA:: Read from foreign files.
* IMPORT:: Read from a portable file.
-* MATCH FILES:: Merge system files.
* SAVE:: Write to a system file.
* SYSFILE INFO:: Display system file dictionary.
* XEXPORT:: Write to a portable file, as a transformation.
system file are considered. Variables with the same name but different
types (numeric, string) will cause an error message. Otherwise, the
system file variables' attributes will replace those in their matching
-active file variables, as described below.
+active file variables:
+@itemize @bullet
+@item
If a system file variable has a variable label, then it will replace the
active file variable's variable label. If the system file variable does
not have a variable label, then the active file variable's variable
-label, if any, will be retained.
+label, if any, will be retained.
+
+@item
+If the system file variable has custom attributes (@pxref{VARIABLE
+ATTRIBUTE}), then those attributes replace the active file variable's
+custom attributes. If the system file variable does not have custom
+attributes, then the active file variable's custom attributes, if any,
+will be retained.
+@item
If the active file variable is numeric or short string, then value
labels and missing values, if any, will be copied to the active file
variable. If the system file variable does not have value labels or
missing values, then those in the active file variable, if any, will not
be disturbed.
+@end itemize
-Finally, weighting of the active file is updated (@pxref{WEIGHT}). If
-the active file has a weighting variable, and the system file does not,
-or if the weighting variable in the system file does not exist in the
-active file, then the active file weighting variable, if any, is
-retained. Otherwise, the weighting variable in the system file becomes
-the active file weighting variable.
+In addition to properties of variables, some properties of the active
+file dictionary as a whole are updated:
+
+@itemize @bullet
+@item
+If the system file has custom attributes (@pxref{DATAFILE ATTRIBUTE}),
+then those attributes replace the active file variable's custom
+attributes.
+
+@item
+If the active file has a weighting variable (@pxref{WEIGHT}), and the
+system file does not, or if the weighting variable in the system file
+does not exist in the active file, then the active file weighting
+variable, if any, is retained. Otherwise, the weighting variable in
+the system file becomes the active file weighting variable.
+@end itemize
@cmd{APPLY DICTIONARY} takes effect immediately. It does not read the
active
Use of @cmd{GET} to read a portable file or scratch file is a PSPP
extension.
+@node GET DATA
+@section GET DATA
+@vindex GET DATA
+
+@display
+GET DATA
+ /TYPE=@{GNM,PSQL,TXT@}
+ @dots{}additional subcommands depending on TYPE@dots{}
+@end display
+
+The @cmd{GET DATA} command is used to read files and other data sources
+created by other applications.
+When this command is executed, the current dictionary and active file are
+replaced with variables and data read from the specified source.
+
+The TYPE subcommand is mandatory and must be the first subcommand
+specified. It determines the type of the file or source to read.
+PSPP currently supports the following file types:
+
+@table @asis
+@item GNM
+Spreadsheet files created by Gnumeric (@url{http://gnumeric.org}).
+
+@item PSQL
+Relations from PostgreSQL databases (@url{http://postgresql.org}).
+
+@item TXT
+Textual data files in columnar and delimited formats.
+@end table
+
+Each supported file type has additional subcommands, explained in
+separate sections below.
+
+@menu
+* GET DATA /TYPE=GNM::
+* GET DATA /TYPE=PSQL::
+* GET DATA /TYPE=TXT::
+@end menu
+
+@node GET DATA /TYPE=GNM
+@subsection Gnumeric Spreadsheet Files
+
+@display
+GET DATA /TYPE=GNM
+ /FILE=@{'file-name'@}
+ /SHEET=@{NAME 'sheet-name', INDEX n@}
+ /CELLRANGE=@{RANGE 'range', FULL@}
+ /READNAMES=@{ON, OFF@}
+ /ASSUMEDVARWIDTH=n.
+@end display
+
+@cindex Gnumeric
+@cindex spreadsheet files
+To use GET DATA to read a spreadsheet file created by Gnumeric
+(@url{http://gnumeric.org}), specify TYPE=GNM to indicate the file's
+format and use FILE to indicate the Gnumeric file to be read. All
+other subcommands are optional.
+
+The format of each variable is determined by the format of the spreadsheet
+cell containing the first datum for the variable.
+If this cell is of string (text) format, then the width of the variable is
+determined from the length of the string it contains, unless the
+ASSUMEDVARWIDTH subcommand is given.
+
+
+The FILE subcommand is mandatory. Specify the name of the file
+to be read.
+
+The SHEET subcommand specifies the sheet within the spreadsheet file to read.
+There are two forms of the SHEET subcommand.
+In the first form,
+@samp{/SHEET=name @var{sheet-name}}, the string @var{sheet-name} is the
+name of the sheet to read.
+In the second form, @samp{/SHEET=index @var{idx}}, @var{idx} is a
+integer which is the index of the sheet to read.
+The first sheet has the index 1.
+If the SHEET subcommand is omitted, then the command will read the
+first sheet in the file.
+
+The CELLRANGE subcommand specifies the range of cells within the sheet to read.
+If the subcommand is given as @samp{/CELLRANGE=FULL}, then the entire
+sheet is read.
+To read only part of a sheet, use the form
+@samp{/CELLRANGE=range '@var{top-left-cell}:@var{bottom-right-cell}'}.
+For example, the subcommand @samp{/CELLRANGE=range 'C3:P19'} reads
+columns C--P, and rows 3--19 inclusive.
+If no CELLRANGE subcommand is given, then the entire sheet is read.
+
+If @samp{/READNAMES=ON} is specified, then the contents of cells of
+the first row are used as the names of the variables in which to store
+the data from subsequent rows.
+If the READNAMES command is omitted, or if @samp{/READNAMES=OFF} is
+used, then the variables receive automatically assigned names.
+
+The ASSUMEDVARWIDTH subcommand specifies the maximum width of string
+variables read from the file.
+If omitted, the default value is determined from the length of the
+string in the first spreadsheet cell for each variable.
+
+
+@node GET DATA /TYPE=PSQL
+@subsection Postgres Database Queries
+
+@display
+GET DATA /TYPE=PSQL
+ /CONNECT=@{connection info@}
+ /SQL=@{query@}
+ [/ASSUMEDVARWIDTH=n]
+ [/UNENCRYPTED]
+ [/BSIZE=n].
+@end display
+
+@cindex postgres
+@cindex databases
+
+The PSQL type is used to import data from a postgres database server.
+The server may be located locally or remotely.
+Variables are automatically created based on the table column names
+or the names specified in the SQL query.
+Postgres data types of high precision, will loose precision when
+imported into PSPP.
+Not all the postgres data types are able to be represented in PSPP.
+If a datum cannot be represented a warning will be issued and that
+datum will be set to SYSMIS.
+
+The CONNECT subcommand is mandatory.
+It is a string specifying the parameters of the database server from
+which the data should be fetched.
+The format of the string is given in the postgres manual
+@url{http://www.postgresql.org/docs/8.0/static/libpq.html#LIBPQ-CONNECT}.
+
+The SQL subcommand is mandatory.
+It must be a valid SQL string to retrieve data from the database.
+
+The ASSUMEDVARWIDTH subcommand specifies the maximum width of string
+variables read from the database.
+If omitted, the default value is determined from the length of the
+string in the first value read for each variable.
+
+The UNENCRYPTED subcommand allows data to be retrieved over an insecure
+connection.
+If the connection is not encrypted, and the UNENCRYPTED subcommand is not
+given, then an error will occur.
+Whether or not the connection is
+encrypted depends upon the underlying psql library and the
+capabilities of the database server.
+
+The BSIZE subcommand serves only to optimise the speed of data transfer.
+It specifies an upper limit on
+number of cases to fetch from the database at once.
+The default value is 4096.
+If your SQL statement fetches a large number of cases but only a small number of
+variables, then the data transfer may be faster if you increase this value.
+Conversely, if the number of variables is large, or if the machine on which
+PSPP is running has only a
+small amount of memory, then a smaller value will be better.
+
+
+The following syntax is an example:
+@example
+GET DATA /TYPE=PSQL
+ /CONNECT='host=example.com port=5432 dbname=product user=fred passwd=xxxx'
+ /SQL='select * from manufacturer'.
+@end example
+
+
+@node GET DATA /TYPE=TXT
+@subsection Textual Data Files
+
+@display
+GET DATA /TYPE=TXT
+ /FILE=@{'file-name',file_handle@}
+ [/ARRANGEMENT=@{DELIMITED,FIXED@}]
+ [/FIRSTCASE=@{first_case@}]
+ [/IMPORTCASE=@{ALL,FIRST max_cases,PERCENT percent@}]
+ @dots{}additional subcommands depending on ARRANGEMENT@dots{}
+@end display
+
+@cindex text files
+@cindex data files
+When TYPE=TXT is specified, GET DATA reads data in a delimited or
+fixed columnar format, much like DATA LIST (@pxref{DATA LIST}).
+
+The FILE subcommand is mandatory. Specify the file to be read as
+a string file name or (for textual data
+only) a file handle (@pxref{File Handles}).
+
+The ARRANGEMENT subcommand determines the file's basic format.
+DELIMITED, the default setting, specifies that fields in the input
+data are separated by spaces, tabs, or other user-specified
+delimiters. FIXED specifies that fields in the input data appear at
+particular fixed column positions within records of a case.
+
+By default, cases are read from the input file starting from the first
+line. To skip lines at the beginning of an input file, set FIRSTCASE
+to the number of the first line to read: 2 to skip the first line, 3
+to skip the first two lines, and so on.
+
+IMPORTCASE can be used to limit the number of cases read from the
+input file. With the default setting, ALL, all cases in the file are
+read. Specify FIRST @i{max_cases} to read at most @i{max_cases} cases
+from the file. Use PERCENT @i{percent} to read only @i{percent}
+percent, approximately, of the cases contained in the file. (The
+percentage is approximate, because there is no way to accurately count
+the number of cases in the file without reading the entire file. The
+number of cases in some kinds of unusual files cannot be estimated;
+PSPP will read all cases in such files.)
+
+FIRSTCASE and IMPORTCASE may be used with delimited and fixed-format
+data. The remaining subcommands, which apply only to one of the two file
+arrangements, are described below.
+
+@menu
+* GET DATA /TYPE=TXT /ARRANGEMENT=DELIMITED::
+* GET DATA /TYPE=TXT /ARRANGEMENT=FIXED::
+@end menu
+
+@node GET DATA /TYPE=TXT /ARRANGEMENT=DELIMITED
+@subsubsection Reading Delimited Data
+
+@display
+GET DATA /TYPE=TXT
+ /FILE=@{'file-name',file_handle@}
+ [/ARRANGEMENT=@{DELIMITED,FIXED@}]
+ [/FIRSTCASE=@{first_case@}]
+ [/IMPORTCASE=@{ALL,FIRST max_cases,PERCENT percent@}]
+
+ /DELIMITERS="delimiters"
+ [/QUALIFIER="quotes" [/ESCAPE]]
+ [/DELCASE=@{LINE,VARIABLES n_variables@}]
+ /VARIABLES=del_var [del_var]@dots{}
+where each del_var takes the form:
+ variable format
+@end display
+
+The GET DATA command with TYPE=TXT and ARRANGEMENT=DELIMITED reads
+input data from text files in delimited format, where fields are
+separated by a set of user-specified delimiters. Its capabilities are
+similar to those of DATA LIST FREE (@pxref{DATA LIST FREE}), with a
+few enhancements.
+
+The required FILE subcommand and optional FIRSTCASE and IMPORTCASE
+subcommands are described above (@pxref{GET DATA /TYPE=TXT}).
+
+DELIMITERS, which is required, specifies the set of characters that
+may separate fields. Each character in the string specified on
+DELIMITERS separates one field from the next. The end of a line also
+separates fields, regardless of DELIMITERS. Two consecutive
+delimiters in the input yield an empty field, as does a delimiter at
+the end of a line. A space character as a delimiter is an exception:
+consecutive spaces do not yield an empty field and neither does any
+number of spaces at the end of a line.
+
+To use a tab as a delimiter, specify @samp{\t} at the beginning of the
+DELIMITERS string. To use a backslash as a delimiter, specify
+@samp{\\} as the first delimiter or, if a tab should also be a
+delimiter, immediately following @samp{\t}. To read a data file in
+which each field appears on a separate line, specify the empty string
+for DELIMITERS.
+
+The optional QUALIFIER subcommand names one or more characters that
+can be used to quote values within fields in the input. A field that
+begins with one of the specified quote characters ends at the next
+matching quote. Intervening delimiters become part of the field,
+instead of terminating it. The ability to specify more than one quote
+character is a PSPP extension.
+
+By default, a character specified on QUALIFIER cannot itself be
+embedded within a field that it quotes, because the quote character
+always terminates the quoted field. With ESCAPE, however, a doubled
+quote character within a quoted field inserts a single instance of the
+quote into the field. For example, if @samp{'} is specified on
+QUALIFIER, then without ESCAPE @code{'a''b'} specifies a pair of
+fields that contain @samp{a} and @samp{b}, but with ESCAPE it
+specifies a single field that contains @samp{a'b}. ESCAPE is a PSPP
+extension.
+
+The DELCASE subcommand controls how data may be broken across lines in
+the data file. With LINE, the default setting, each line must contain
+all the data for exactly one case. For additional flexibility, to
+allow a single case to be split among lines or multiple cases to be
+contained on a single line, specify VARIABLES @i{n_variables}, where
+@i{n_variables} is the number of variables per case.
+
+The VARIABLES subcommand is required and must be the last subcommand.
+Specify the name of each variable and its input format (@pxref{Input
+and Output Formats}) in the order they should be read from the input
+file.
+
+@subsubheading Examples
+
+@noindent
+On a Unix-like system, the @samp{/etc/passwd} file has a format
+similar to this:
+
+@example
+root:$1$nyeSP5gD$pDq/:0:0:,,,:/root:/bin/bash
+blp:$1$BrP/pFg4$g7OG:1000:1000:Ben Pfaff,,,:/home/blp:/bin/bash
+john:$1$JBuq/Fioq$g4A:1001:1001:John Darrington,,,:/home/john:/bin/bash
+jhs:$1$D3li4hPL$88X1:1002:1002:Jason Stover,,,:/home/jhs:/bin/csh
+@end example
+
+@noindent
+The following syntax reads a file in the format used by
+@samp{/etc/passwd}:
+
+@c If you change this example, change the regression test in
+@c tests/command/get-data-txt-examples.sh to match.
+@example
+GET DATA /TYPE=TXT /FILE='/etc/passwd' /DELIMITERS=':'
+ /VARIABLES=username A20
+ password A40
+ uid F10
+ gid F10
+ gecos A40
+ home A40
+ shell A40.
+@end example
+
+@noindent
+Consider the following data on used cars:
+
+@example
+model year mileage price type age
+Civic 2002 29883 15900 Si 2
+Civic 2003 13415 15900 EX 1
+Civic 1992 107000 3800 n/a 12
+Accord 2002 26613 17900 EX 1
+@end example
+
+@noindent
+The following syntax can be used to read the used car data:
+
+@c If you change this example, change the regression test in
+@c tests/command/get-data-txt-examples.sh to match.
+@example
+GET DATA /TYPE=TXT /FILE='cars.data' /DELIMITERS=' ' /FIRSTCASE=2
+ /VARIABLES=model A8
+ year F4
+ mileage F6
+ price F5
+ type A4
+ age F2.
+@end example
+
+@noindent
+Consider the following information on animals in a pet store:
+
+@example
+'Pet''s Name', "Age", "Color", "Date Received", "Price", "Height", "Type"
+, (Years), , , (Dollars), ,
+"Rover", 4.5, Brown, "12 Feb 2004", 80, '1''4"', "Dog"
+"Charlie", , Gold, "5 Apr 2007", 12.3, "3""", "Fish"
+"Molly", 2, Black, "12 Dec 2006", 25, '5"', "Cat"
+"Gilly", , White, "10 Apr 2007", 10, "3""", "Guinea Pig"
+@end example
+
+@noindent
+The following syntax can be used to read the pet store data:
+
+@c If you change this example, change the regression test in
+@c tests/command/get-data-txt-examples.sh to match.
+@example
+GET DATA /TYPE=TXT /FILE='pets.data' /DELIMITERS=', ' /QUALIFIER='''"' /ESCAPE
+ /FIRSTCASE=3
+ /VARIABLES=name A10
+ age F3.1
+ color A5
+ received EDATE10
+ price F5.2
+ height a5
+ type a10.
+@end example
+
+@node GET DATA /TYPE=TXT /ARRANGEMENT=FIXED
+@subsubsection Reading Fixed Columnar Data
+
+@display
+GET DATA /TYPE=TXT
+ /FILE=@{'file-name',file_handle@}
+ [/ARRANGEMENT=@{DELIMITED,FIXED@}]
+ [/FIRSTCASE=@{first_case@}]
+ [/IMPORTCASE=@{ALL,FIRST max_cases,PERCENT percent@}]
+
+ [/FIXCASE=n]
+ /VARIABLES fixed_var [fixed_var]@dots{}
+ [/rec# fixed_var [fixed_var]@dots{}]@dots{}
+where each fixed_var takes the form:
+ variable start-end format
+@end display
+
+The GET DATA command with TYPE=TXT and ARRANGEMENT=FIXED reads input
+data from text files in fixed format, where each field is located in
+particular fixed column positions within records of a case. Its
+capabilities are similar to those of DATA LIST FIXED (@pxref{DATA LIST
+FIXED}), with a few enhancements.
+
+The required FILE subcommand and optional FIRSTCASE and IMPORTCASE
+subcommands are described above (@pxref{GET DATA /TYPE=TXT}).
+
+The optional FIXCASE subcommand may be used to specify the positive
+integer number of input lines that make up each case. The default
+value is 1.
+
+The VARIABLES subcommand, which is required, specifies the positions
+at which each variable can be found. For each variable, specify its
+name, followed by its start and end column separated by @samp{-}
+(e.g.@: @samp{0-9}), followed by the input format type (e.g.@:
+@samp{F}). For this command, columns are numbered starting from 0 at
+the left column. Introduce the variables in the second and later
+lines of a case by a slash followed by the number of the line within
+the case, e.g.@: @samp{/2} for the second line.
+
+@subsubheading Examples
+
+@noindent
+Consider the following data on used cars:
+
+@example
+model year mileage price type age
+Civic 2002 29883 15900 Si 2
+Civic 2003 13415 15900 EX 1
+Civic 1992 107000 3800 n/a 12
+Accord 2002 26613 17900 EX 1
+@end example
+
+@noindent
+The following syntax can be used to read the used car data:
+
+@c If you change this example, change the regression test in
+@c tests/command/get-data-txt-examples.sh to match.
+@example
+GET DATA /TYPE=TXT /FILE='cars.data' /ARRANGEMENT=FIXED /FIRSTCASE=2
+ /VARIABLES=model 0-7 A
+ year 8-15 F
+ mileage 16-23 F
+ price 24-31 F
+ type 32-40 A
+ age 40-47 F.
+@end example
+
@node IMPORT
@section IMPORT
@vindex IMPORT
Use of @cmd{IMPORT} to read a system file or scratch file is a PSPP
extension.
-@node MATCH FILES
-@section MATCH FILES
-@vindex MATCH FILES
-
-@display
-MATCH FILES
- /@{FILE,TABLE@}=@{*,'file-name'@}
- /DROP=var_list
- /KEEP=var_list
- /RENAME=(src_names=target_names)@dots{}
- /IN=var_name
-
- /BY var_list
- /FIRST=var_name
- /LAST=var_name
- /MAP
-@end display
-
-@cmd{MATCH FILES} merges one or more system, portable, or scratch files,
-optionally
-including the active file. Records with the same values for BY
-variables are combined into a single record. Records with different
-values are output in order. Thus, multiple sorted files are
-combined into a single sorted file based on the value of the BY
-variables. The results of the merge become the new active file.
-
-The BY subcommand specifies a list of variables that are used to match
-records from each of the files. Variables specified must exist
-in all the files specified on FILE and TABLE. BY should usually be
-specified. If TABLE or IN is used then BY is required.
-
-Specify FILE with a system, portable, or scratch file as a file name
-string or file handle
-(@pxref{File Handles}), or with an asterisk (@samp{*}) to
-indicate the current active file. The files specified on FILE are
-merged together based on the BY variables, or combined case-by-case if
-BY is not specified. Normally at least two FILE subcommands should be
-specified.
-
-Specify TABLE with a file to use it as a @dfn{table
-lookup file}. Records in table lookup files are not used up after
-they've been used once. This means that data in table lookup files can
-correspond to any number of records in FILE files. Table lookup files
-correspond to lookup tables in traditional relational database systems.
-It is incorrect to have records with duplicate BY values in table lookup
-files.
-
-Any number of FILE and TABLE subcommands may be specified. Each
-instance of FILE or TABLE can be followed by any sequence of DROP,
-KEEP, or RENAME subcommands. These have the same form and meaning as
-the corresponding subcommands of @cmd{GET} (@pxref{GET}), but apply
-only to variables in the given file.
-
-Each FILE or TABLE may optionally be followed by an IN subcommand,
-which creates a numeric variable with the specified name and format
-F1.0. The IN variable takes value 1 in a case if the given file
-contributed a row to the merged file, 0 otherwise. The DROP, KEEP,
-and RENAME subcommands do not affect IN variables.
-
-Variables belonging to files that are not present for the current case
-are set to the system-missing value for numeric variables or spaces for
-string variables.
-
-FIRST, LAST, and MAP are currently ignored.
-
-@cmd{MATCH FILES} may not be specified following @cmd{TEMPORARY}
-(@pxref{TEMPORARY}) if the active file is used as an input source.
-
-Use of portable or scratch files on @cmd{MATCH FILES} is a PSPP
-extension.
-
@node SAVE
@section SAVE
@vindex SAVE
@vindex XEXPORT
@display
-EXPORT
+XEXPORT
/OUTFILE='file-name'
/DIGITS=n
/DROP=var_list
@end itemize
@xref{SAVE}, for more information.
-@setfilename ignored
projects / pspp-builds.git / blobdiff