.. _cli::p3-extract:


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p3-extract
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Select Columns from an Input File
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.. code-block:: perl

     p3-extract [options] col1 col2 ... colN


This script extracts the specified columns from a tab-delimited file.

Parameters
==========


The positional parameters are the numbers or names of the columns to include in the output. The column numbers
are 1-based, and the column names are taken from the header record of the input file.

The standard input may be overridden by the command-line options given in :ref:`cli-input-options`.

The following additional options are supported.


- all
 
 Output all the columns. This simply copies the file.
 


- reverse
 
 Output all the columns not listed, rather than the listed columns.
 


- nohead
 
 If specified, the file is presumed to have no headers.