1DBSORT(1)             User Contributed Perl Documentation            DBSORT(1)
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NAME

6       dbsort - sort rows based on the the specified columns
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SYNOPSIS

9           dbsort [-M MemLimit] [-T TemporaryDirectory] [-nNrR] column [column...]
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DESCRIPTION

12       Sort all input rows as specified by the numeric or lexical columns.
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14       Dbsort consumes a fixed amount of memory regardless of input size.  (It
15       reverts to temporary files on disk if necessary, based on the -M and -T
16       options.)
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18       The sort should be stable, but this has not yet been verified.
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20       For large inputs (those that spill to disk), dbsort will do some of the
21       merging in parallel, if possible.  The --parallel option can control
22       the degree of parallelism, if desired.
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OPTIONS

25       General option:
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27       -M MaxMemBytes
28           Specify an approximate limit on memory usage (in bytes).  Larger
29           values allow faster sorting because more operations happen in-
30           memory, provided you have enough memory.
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32       -T TmpDir
33           where to put tmp files.  Also uses environment variable TMPDIR, if
34           -T is not specified.  Default is /tmp.
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36       --parallelism N or -j N
37           Allow up to N merges to happen in parallel.  Default is the number
38           of CPUs in the machine.
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40       Sort specification options (can be interspersed with column names):
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42       -r or --descending
43           sort in reverse order (high to low)
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45       -R or --ascending
46           sort in normal order (low to high)
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48       -n or --numeric
49           sort numerically
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51       -N or --lexical
52           sort lexicographically
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54       This module also supports the standard fsdb options:
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56       -d  Enable debugging output.
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58       -i or --input InputSource
59           Read from InputSource, typically a file name, or "-" for standard
60           input, or (if in Perl) a IO::Handle, Fsdb::IO or Fsdb::BoundedQueue
61           objects.
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63       -o or --output OutputDestination
64           Write to OutputDestination, typically a file name, or "-" for
65           standard output, or (if in Perl) a IO::Handle, Fsdb::IO or
66           Fsdb::BoundedQueue objects.
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68       --autorun or --noautorun
69           By default, programs process automatically, but Fsdb::Filter
70           objects in Perl do not run until you invoke the run() method.  The
71           "--(no)autorun" option controls that behavior within Perl.
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73       --header H
74           Use H as the full Fsdb header, rather than reading a header from
75           then input.
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77       --help
78           Show help.
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80       --man
81           Show full manual.
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SAMPLE USAGE

84   Input:
85           #fsdb cid cname
86           10 pascal
87           11 numanal
88           12 os
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90   Command:
91           cat data.fsdb | dbsort cname
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93   Output:
94           #fsdb      cid     cname
95           11 numanal
96           12 os
97           10 pascal
98           #  | dbsort cname
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SEE ALSO

101       dbmerge(1), dbmapreduce(1), Fsdb(3)
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104       Copyright (C) 1991-2018 by John Heidemann <johnh@isi.edu>
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106       This program is distributed under terms of the GNU general public
107       license, version 2.  See the file COPYING with the distribution for
108       details.
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112perl v5.34.0                      2021-07-22                         DBSORT(1)
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