Ubuntu Manpage: stilts-tcat - Concatenates multiple similar tables

NAME

       stilts-tcat - Concatenates multiple similar tables

SYNOPSIS

       stilts tcat [in=<table> [<table> ...]] [ifmt=<in-format>] [multi=true|false] [istream=true|false]
                   [icmd=<cmds>] [ocmd=<cmds>] [omode=out|meta|stats|count|cgi|discard|topcat|samp|tosql|gui]
                   [out=<out-table>] [ofmt=<out-format>] [seqcol=<colname>] [loccol=<colname>]
                   [uloccol=<colname>] [lazy=true|false] [countrows=true|false]

DESCRIPTION

       tcat is a tool for concatenating any number of similar tables one after the other. The tables must be  of
       similar  form  to  each other (same number and types of columns). Preprocessing of the tables may be done
       using the icmd parameter, which will operate in the same way on all the input tables. Table parameters of
       the output table will be taken from the first of the input tables.

       Subject  to  some  constraints  on  the  details  of the input and output formats and processing, tcat is
       capable of joining an unlimited number of tables together to produce an output table of unlimited length,
       without large memory requirements.

       If  you  have  heterogeneous tables, in different formats or requiring different preprocessing steps from
       each other before they can be concatenated, use tcatn instead.

OPTIONS

in=<table> [<table> ...]
Locations of the input tables. Either specify the parameter multiple times, or supply the input
tables as a space-separated list within a single use.

The following table location forms are allowed:

* A filename.

* A URL.

* The special value "-", meaning standard input. In this case the input format must be given
explicitly using the ifmt parameter. Note that not all formats can be streamed in this way.

* A system command line with either a "<" character at the start, or a "|" character at the end
("<syscmd" or "syscmd|"). This executes the given pipeline and reads from its standard output.
This will probably only work on unix-like systems.
Compression in any of the supported compression formats (Unix compress, gzip or bzip2) is
expanded automatically.

A list of input table locations may be given in an external file by using the indirction character
'@'. Thus "in=@filename" causes the file filename to be read for a list of input table locations.
The locations in the file should each be on a separate line.

ifmt=<in-format>
Specifies the format of the input table as specified by parameter in. The known formats are listed
in SUN/256. This flag can be used if you know what format your table is in. If it has the special
value (auto) (the default), then an attempt will be made to detect the format of the table
automatically. This cannot always be done correctly however, in which case the program will exit
with an error explaining which formats were attempted.

The same format parameter applies to all the tables specified by in.

multi=true|false
Determines whether all tables, or just the first one, from input table files will be used. If set
false, then just the first table from each file named by in will be used. If true, then all tables
present in those input files will be used. This only has an effect for file formats which are
capable of containing more than one table, which effectively means FITS and VOTable and their
variants.

istream=true|false
If set true, the input table specified by the in parameter will be read as a stream. It is
necessary to give the ifmt parameter in this case. Depending on the required operations and
processing mode, this may cause the read to fail (sometimes it is necessary to read the table more
than once). It is not normally necessary to set this flag; in most cases the data will be streamed
automatically if that is the best thing to do. However it can sometimes result in less resource
usage when processing large files in certain formats (such as VOTable).

The same streaming flag applies to all the tables specified by in.

icmd=<cmds>
Specifies processing to be performed on each input table as specified by parameter in, before any
other processing has taken place. The value of this parameter is one or more of the filter
commands described in SUN/256. If more than one is given, they must be separated by semicolon
characters (";"). This parameter can be repeated multiple times on the same command line to build
up a list of processing steps. The sequence of commands given in this way defines the processing
pipeline which is performed on the table.

Commands may alteratively be supplied in an external file, by using the indirection character '@'.
Thus a value of "@filename" causes the file filename to be read for a list of filter commands to
execute. The commands in the file may be separated by newline characters and/or semicolons, and
lines which are blank or which start with a '#' character are ignored.

ocmd=<cmds>
Specifies processing to be performed on the output table, after all other processing has taken
place. The value of this parameter is one or more of the filter commands described in SUN/256. If
more than one is given, they must be separated by semicolon characters (";"). This parameter can
be repeated multiple times on the same command line to build up a list of processing steps. The
sequence of commands given in this way defines the processing pipeline which is performed on the
table.

omode=out|meta|stats|count|cgi|discard|topcat|samp|tosql|gui
The mode in which the result table will be output. The default mode is out, which means that the
result will be written as a new table to disk or elsewhere, as determined by the out and ofmt
parameters. However, there are other possibilities, which correspond to uses to which a table can
be put other than outputting it, such as displaying metadata, calculating statistics, or
populating a table in an SQL database. For some values of this parameter, additional parameters
(<mode-args>) are required to determine the exact behaviour.

Possible values are

* out

* meta

* stats

* count

* cgi

* discard

* topcat

* samp

* tosql

* gui
Use the help=omode flag or see SUN/256 for more information.

out=<out-table>
The location of the output table. This is usually a filename to write to. If it is equal to the
special value "-" (the default) the output table will be written to standard output.

This parameter must only be given if omode has its default value of "out".

ofmt=<out-format>
Specifies the format in which the output table will be written (one of the ones in SUN/256 -
matching is case-insensitive and you can use just the first few letters). If it has the special
value "(auto)" (the default), then the output filename will be examined to try to guess what sort
of file is required usually by looking at the extension. If it's not obvious from the filename
what output format is intended, an error will result.

This parameter must only be given if omode has its default value of "out".

seqcol=<colname>
Name of a column to be added to the output table which will contain the sequence number of the
input table from which each row originated. This column will contain 1 for the rows from the first
concatenated table, 2 for the second, and so on.

loccol=<colname>
Name of a column to be added to the output table which will contain the location (as specified in
the input parameter(s)) of the input table from which each row originated.

uloccol=<colname>
Name of a column to be added to the output table which will contain the unique part of the
location (as specified in the input parameter(s)) of the input table from which each row
originated. If not null, parameters will also be added to the output table giving the pre- and
post-fix string common to all the locations. For example, if the input tables are
"/data/cat_a1.fits" and "/data/cat_b2.fits" then the output table will contain a new column
<colname> which takes the value "a1" for rows from the first table and "b2" for rows from the
second, and new parameters "<colname>_prefix" and "<colname>_postfix" with the values "/data/cat_"
and ".fits" respectively.

lazy=true|false
Whether to perform table resolution lazily. If true, each table is only accessed when the time
comes to add its rows to the output; if false, then all the tables are accessed up front. This is
mostly a tuning parameter, and on the whole it doesn't matter much how it is set, but for joining
an enormous number of tables setting it true may avoid running out of resources.

countrows=true|false
Whether to count the rows in the table before starting the output. This is essentially a tuning
parameter - if writing to an output format which requires the number of rows up front (such as
normal FITS) it may result in skipping the number of passes through the input files required for
processing. Unless you have a good understanding of the internals of the software, your best bet
for working out whether to set this true or false is to try it both ways

VERSION

       STILTS version 3.2-debian

       This  is the Debian version of Stilts, which lack the support of some file formats and network protocols.
       For differences see
       file:///usr/share/doc/stilts/README.Debian

AUTHOR