/ 
Fsdb-3.4
River stage zero No dependents
/ Fsdb::Filter::dbmerge2

NAME

dbmerge2 - merge exactly two inputs in sorted order based on the the specified columns

SYNOPSIS

dbmerge2 --input A.fsdb --input B.fsdb [-T TemporaryDirectory] [-nNrR] column [column...]

or cat A.fsdb | dbmerge2 --input B.fsdb [-T TemporaryDirectory] [-nNrR] column [column...]

DESCRIPTION

Merge exactly two sorted input files, producing one sorted result. Inputs can both be specified with --input, or one can come from standard input and the other from --input.

Inputs must have identical schemas (columns, column order, and field separators).

Dbmerge2 consumes a fixed amount of memory regardless of input size.

Although described above as a command line too, the command line version of dbmerge2 is not installed by default. Dbmerge2 is used primarily internal to perl; dbmerge(1) is the command-line tool for user use.

Warning: we do not verify that each input is actually sorted. In correct merge results will occur if they are not.

OPTIONS

General option:

--saveoutput $OUT_REF

Save output writer (for integration with other fsdb filters).

<-T TmpDir>

where to put tmp files. Also uses environment variable TMPDIR, if -T is not specified. Default is /tmp.

Sort specification options (can be interspersed with column names):

-r or --descending

sort in reverse order (high to low)

-R or --ascending

sort in normal order (low to high)

-n or --numeric

sort numerically

-N or --lexical

sort lexicographically

This module also supports the standard fsdb options:

-d

Enable debugging output.

-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:

File a.fsdb:

#fsdb cid cname
11 numanal
10 pascal

File b.fsdb:

#fsdb cid cname
12 os
13 statistics

Command:

dbmerge2 --input a.fsdb --input b.fsdb cname

or

cat a.fsdb | dbmerge2 --input b.fsdb cname

Output:

#fsdb      cid     cname
11 numanal
12 os
10 pascal
13 statistics
#  | dbmerge2 --input a.fsdb --input b.fsdb cname

SEE ALSO

dbmerge(1), dbsort(1), Fsdb(3)

CLASS FUNCTIONS

new

$filter = new Fsdb::Filter::dbmerge2(@arguments);

Create a new 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) 1991-2022 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.