1DBSORT(1)             User Contributed Perl Documentation            DBSORT(1)
2
3
4

NAME

6       dbsort - sort rows based on the the specified columns
7

SYNOPSIS

9           dbsort [-M MemLimit] [-T TemporaryDirectory] [-nNrR] column [column...]
10

DESCRIPTION

12       Sort all input rows as specified by the numeric or lexical columns.
13
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.)
17
18       The sort should be stable, but this has not yet been verified.
19
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.
23

OPTIONS

25       General option:
26
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.
31
32       -T TmpDir
33           where to put tmp files.  Also uses environment variable TMPDIR, if
34           -T is not specified.  Default is /tmp.
35
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.
39
40       Sort specification options (can be interspersed with column names):
41
42       -r or --descending
43           sort in reverse order (high to low)
44
45       -R or --ascending
46           sort in normal order (low to high)
47
48       -n or --numeric
49           sort numerically
50
51       -N or --lexical
52           sort lexicographically
53
54       This module also supports the standard fsdb options:
55
56       -d  Enable debugging output.
57
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.
62
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.
67
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.
72
73       --header H
74           Use H as the full Fsdb header, rather than reading a header from
75           then input.
76
77       --help
78           Show help.
79
80       --man
81           Show full manual.
82

SAMPLE USAGE

84   Input:
85           #fsdb cid cname
86           10 pascal
87           11 numanal
88           12 os
89
90   Command:
91           cat data.fsdb | dbsort cname
92
93   Output:
94           #fsdb      cid     cname
95           11 numanal
96           12 os
97           10 pascal
98           #  | dbsort cname
99

SEE ALSO

101       dbmerge(1), dbmapreduce(1), Fsdb(3)
102

104       Copyright (C) 1991-2018 by John Heidemann <johnh@isi.edu>
105
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.
109
110
111
112perl v5.28.1                      2019-02-02                         DBSORT(1)
Impressum