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)
AUTHOR and COPYRIGHT
Copyright (C) 1991-2022 by John Heidemann <johnh AT isi DOT edu>
This program is distributed under terms of the GNU general public license, version 2. See the file COPYING with the distribution for details.