Dbmerge2 (1) Linux Manual Page

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

 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

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

dbmerge2 (1) Linux Manual Page