tbl-dctrl(1) Debian administrator's manual tbl-dctrl(1)
NAME
tbl-dctrl - generate tabular representations of data in dctrl format
SYNOPSIS
tbl-dctrl [ options ] [ -c column-specification ... ] [ filename ] ...
tbl-dctrl --version
tbl-dctrl --help
DESCRIPTION
tbl-dctrl creates tabular representations of data given to it in Debian
control file format.
By default, tbl-dctrl reads the whole database, looking for the longest
entry in each requested column; it then outputs a table, with borders
and column titles, where each column is just wide enough to fit the
longest entry. Most of this behaviour can be customized as described
below.
A column is requested by specifying the -c (--column) switch with a col-
umn specification. The simplest kind of a column specification consists
solely of the name of a field. In such a case, tbl-dctrl will include
in the output a column whose title is the literal column specification
and whose data is drawn from fields with that name. If no -c options
are given, tbl-dctrl will use all fields in the input in the order in
which they first appear.
There are two optional additions one can make to a column specification.
Prefixing the field name with some text followed by an equality sign
(for example, -c 'Package name=Package') modifies the column in such a
way that the text before the equality sign is used as the column title,
while the text after the equality sign is used as the name of the field
from which data is drawn. One can also append a colon followed by a
positive whole number to the field name. In such a case, the number af-
ter the colon specifies the width of the column. These two additions
can be used separately or together. If there are more than one colon,
the last one is significant. If there are more than one equals sign,
the first one is significant. Other colons and equals signs are used
simply as data. Note that the whole column specification must be given
to tbl-dctrl as one argument, so if it contains spaces, it must be
quoted for the shell.
If all requested columns have a specified width, tbl-dctrl will produce
output immediately, not waiting for the whole input to be read in.
OPTIONS
-d delimiter, --delimiter=delimiter
Instead of drawing nice borders to the table, use the specified
delimiter string to delimit columns in a row.
-H, --no-heading
Do not print a table heading (column titles).
-l level, --errorlevel=level
Set log level to level. level is one of fatal, important, infor-
mational 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 de-
fault 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
tbl-dctrl will read its input from the files named on the command line,
in the specified order. A file called - represents the program's stan-
dard input stream. If no files are named, the program behaves as if -
alone had been named, that is, input is read from the standard input
stream.
STDIN
The standard input stream may be used as input as specified above in the
OPERANDS section.
INPUT FILES
All input to tbl-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 con-
tent. 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 con-
tent. The colon must reside on the first line of the field, and the
first line must start with no whitespace. Subsequent lines, in con-
trast, always start with linear whitespace (one or more space or tab
characters).
When input is read from multiple files, a record separator is implicit
between two adjacent files.
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 a tabu-
lar representation of the input database restricted to the specified
fields. Logically, the output is a table; when the -d option is used,
this table is represented simply by separating columns in each row by
the specified delimiter; when the option is not used, a frame is drawn
around the table. The order of the columns is the same as the order of
the column specifications on the command line.
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 com-
pletely garbage. In case of errors in invocation, the program will
refuse to function.
EXAMPLES
The following command line pipe outputs a table of all packages, with
their maintainer data, sorted by the maintainer data, that have no con-
tent:
% grep-available -FInstalled-Size --eq 0 | sort-dctrl -kMaintainer - \
| tbl-dctrl -cPackage -cMaintainer
AUTHOR
The tbl-dctrl program and this manual page were written by Antti-Juhani
Kaijanaho.
SEE ALSO
apt-cache(1), ara(1), dpkg-awk(1), dpkg-query(1), grep-dctrl(1),
sort-dctrl(1), dpkg(8)
Debian Project 2006-04-02 tbl-dctrl(1)
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