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NAME

dbrow - select rows from an Fsdb file based on arbitrary conditions

SYNOPSIS

dbrow [-vw] CONDITION [CONDITION...]

DESCRIPTION

Select rows for which all CONDITIONS are true. Conditions are specified as Perl code, in which column names are be embedded, preceded by underscores.

OPTIONS

-v

Invert the selection, picking rows where at least one condition does not match.

This module also supports the standard fsdb options:

-d

Enable debugging output.

-w or --warnings

Enable warnings in user supplied code.

-i or --input InputSource

Read from InputSource, typically a file name, or - for standard input, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.

-o or --output OutputDestination

Write to OutputDestination, typically a file name, or - for standard output, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue objects.

--autorun or --noautorun

By default, programs process automatically, but Fsdb::Filter objects in Perl do not run until you invoke the run() method. The --(no)autorun option controls that behavior within Perl.

--header H

Use H as the full Fsdb header, rather than reading a header from then input.

--help

Show help.

--man

Show full manual.

SAMPLE USAGE

Input:

    #fsdb account passwd uid gid fullname homedir shell
    johnh * 2274 134 John_Heidemann /home/johnh /bin/bash
    greg * 2275 134 Greg_Johnson /home/greg /bin/bash
    root * 0 0 Root /root /bin/bash
    # this is a simple database

Command:

    cat DATA/passwd.fsdb | dbrow '_fullname =~ /John/'

Output:

    #fsdb      account passwd  uid     gid     fullname        homedir shell
    johnh   *       2274    134     John_Heidemann  /home/johnh     /bin/bash
    greg    *       2275    134     Greg_Johnson    /home/greg      /bin/bash
    # this is a simple database
    #  | /home/johnh/BIN/DB/dbrow 

BUGS

Doesn't detect references to unknown columns in conditions.

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CLASS FUNCTIONS

new

    $filter = new Fsdb::Filter::dbrow(@arguments);

Create a new dbrow object, taking command-line arguments.

set_defaults

    $filter->set_defaults();

Internal: set up defaults.

parse_options

    $filter->parse_options(@ARGV);

Internal: parse command-line arguments.

setup

    $filter->setup();

Internal: setup, parse headers.

run

    $filter->run();

Internal: run over each rows.

AUTHOR and COPYRIGHT

Copyright (C) 1991-2018 by John Heidemann <johnh@isi.edu>

This program is distributed under terms of the GNU general public license, version 2. See the file COPYING with the distribution for details.