Ubuntu Manpage: join-dctrl - perform relational join on data in dctrl format

NAME

       join-dctrl - perform relational join on data in dctrl format

SYNOPSIS

       join-dctrl [ options ] filename filename

       join-dctrl --version

       join-dctrl --help

DESCRIPTION

       join-dctrl performs a relational join operation on data given to it in Debian control file format.

       A  join  field must be specified using either the switches -1 and -2 or the switch -j.  Conceptually, the
       program creates all ordered pairs of records that can be formed by having a record from the first file as
       the  first  member of the pair and having a record from the second file as the second member of the pair;
       and then it deletes all such pairs where the join fields are not equal.  Effectively, each of  the  input
       files is treated as a relational database table.

       Every input file must be in ascending order on its join field; this allows the program to work fast.  The
       sort-dctrl(1) program can be used to make it so.

OPTIONS

-1 field, --1st-join-field=field
Specify the join field of the first input file.

-2 field, --2nd-join-field=field
Specify the join field of the second input file.

-j field, --join-field=field
Specify a common join field for all files.

-a fileno, --unpairable-from=fileno
Specify that unmatched paragraphs from the first (if 1 is given) or the second (if 2 is given)
file are printed.

-o fieldspec, --output-fields=fieldspec
Specify which fields are included in the output. Fields are separated by commas (more than one -o
option can be used, too). Each field is specified in the format fileno.field in which fileno is
the ordinal number of the input file from which the field is drawn (either 1 or 2), and field
gives the name of the field to use. As a special case, simple 0 can be used instead of
fileno.field to refer to the common value of the join fields.

The name of the field (not including the file number) is used in the output as the name of the
field. However, a different name for output purposes can be specified by suffixing the field
specification by a colon and the preferred visible name.

For example, the option -o 0,1.Version:Old-Version,2.Version specifies that the first field in any
output record should be the join field, the second field should be Old-Version drawing its data
from the Version field of the first input file, and the third field should be Version drawing its
data from the field with the same name in the second input file, and these are the only fields in
an output record.

If no -o option is given, all fields of all the records being joined are included in the output.

-l level, --errorlevel=level
Set log level to level. level is one of fatal, important, informational and debug, but the last
may not be available, depending on the compile-time options. These categories are given here in
order; every message that is emitted when fatal is in effect, will be emitted in the important
error level, and so on. The default is important.

-V, --version
Print out version information.

-C, --copying
Print out the copyright license. This produces much output; be sure to redirect or pipe it
somewhere (such as your favourite pager).

-h, --help
Print out a help summary.

OPERANDS

       join-dctrl  will treat each file named on the command line as a relational database table.  A file called
       - represents the program's standard input stream.  Currently, exactly two files must be named.

STDIN

       The standard input stream may be used as input as specified above in the OPERANDS section.

INPUT FILES

       All input to join-dctrl is in the format of a Debian control file.

       A Debian control (dctrl) file is a semistructured single-table database  stored  in  a  machine-parseable
       text  file.   Such  a database consists of a set of records; each record is a mapping from field names to
       field content.  Textually, records are separated by empty lines, while each field is encoded  as  one  or
       more  nonempty lines inside a record.  A field starts with its name, followed by a colon, followed by the
       field content.  The colon must reside on the first line of the field, and the first line must start  with
       no  whitespace.  Subsequent lines, in contrast, always start with linear whitespace (one or more space or
       tab characters).

       Each input file must be in the ascending order of its join field.

ENVIRONMENT VARIABLES

       The standard locale environment, specifically its character set setting, affects  the  interpretation  of
       input and output as character streams.

ASYNCHRONOUS EVENTS

       Standard UNIX signals have their usual meaning.

STDOUT

       All  output is sent to the standard output stream.  The output is in the format of a Debian control file,
       described above in the INPUT FILES section.  The output will be in the ascending order of the join field,
       if that field is included in the output.

OUTPUT FILES

       There are no output files.

EXIT STATUS

       This  utility  exits with 0 when successful.  It uses a nonzero exit code inconsistently when an error is
       noticed (this is a bug).

CONSEQUENCES OF ERRORS

       In case of errors in the input, the output will be partially or completely garbage.  In case of errors in
       invocation, the program will refuse to function.

EXAMPLES

       Suppose  that  a  file  containing data about binary packages for the AMD64 architecture contained in the
       Debian squeeze (6.0) release, section main, is in the current directory and named Packages.  Suppose that
       we  are  currently on a Debian system.  Suppose further that the current directory does not contain files
       named stat and pkg.  The following commands gives, for each package currently installed and available  in
       Debian  squeeze  (6.0),  its  currently installed version (as Old-Version) and the version in squeeze (as
       New-Version):
       $ sort-dctrl -kPackage /var/lib/dpkg/status > stat
       $ sort-dctrl -kPackage Packages > pkg
       $ join-dctrl -j Package \
         -o 0,1.Version:Old-Version,2.Version:New-Version \
         stat pkg

AUTHOR

       The join-dctrl program and this manual page were written by Antti-Juhani Kaijanaho.