dbmerge2 (1) - Linux Manuals

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

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.

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.

--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

AUTHOR and COPYRIGHT

Copyright (C) 1991-2015 by John Heidemann <johnh [at] 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.