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

NOTE: this page was directly converted from the perl FSDB manual pages from FSDB version 3.1

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)