1MK-FIFO-SPLIT(1) User Contributed Perl Documentation MK-FIFO-SPLIT(1)
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6 mk-fifo-split - Split files and pipe lines to a fifo without really
7 splitting.
8
10 Usage: mk-fifo-split [options] [FILE ...]
11 mk-fifo-split splits FILE and pipes lines to a fifo. With no FILE, or
13 when FILE is -, read standard input.
14 Read hugefile.txt in chunks of a million lines without physically
16 splitting it:
17 mk-fifo-split --lines 1000000 hugefile.txt
19 while [ -e /tmp/mk-fifo-split ]; do cat /tmp/mk-fifo-split; done
20
22 The following section is included to inform users about the potential
23 risks, whether known or unknown, of using this tool. The two main
24 categories of risks are those created by the nature of the tool (e.g.
25 read-only tools vs. read-write tools) and those created by bugs.
26 mk-fifo-split creates and/or deletes the "--fifo" file. Otherwise, no
28 other files are modified, and it merely reads lines from the file given
29 on the command-line. It should be very low-risk.
30 At the time of this release, we know of no bugs that could cause
32 serious harm to users.
33 The authoritative source for updated information is always the online
35 issue tracking system. Issues that affect this tool will be marked as
36 such. You can see a list of such issues at the following URL:
37 <http://www.maatkit.org/bugs/mk-fifo-split>.
38 See also "BUGS" for more information on filing bugs and getting help.
40
42 mk-fifo-split lets you read from a file as though it contains only some
43 of the lines in the file. When you read from it again, it contains the
44 next set of lines; when you have gone all the way through it, the file
45 disappears. This works only on Unix-like operating systems.
46 You can specify multiple files on the command line. If you don't
48 specify any, or if you use the special filename "-", lines are read
49 from standard input.
50
52 This tool accepts additional command-line arguments. Refer to the
53 "SYNOPSIS" and usage information for details.
54 --config
56 type: Array
57 Read this comma-separated list of config files; if specified, this
59 must be the first option on the command line.
60 --fifo
62 type: string; default: /tmp/mk-fifo-split
63 The name of the fifo from which the lines can be read.
65 --force
67 Remove the fifo if it exists already, then create it again.
68 --help
70 Show help and exit.
71 --lines
73 type: int; default: 1000
74 The number of lines to read in each chunk.
76 --offset
78 type: int; default: 0
79 Begin at the Nth line. If the argument is 0, all lines are printed
81 to the fifo. If 1, then beginning at the first line, lines are
82 printed (exactly the same as 0). If 2, the first line is skipped,
83 and the 2nd and subsequent lines are printed to the fifo.
84 --pid
86 type: string
87 Create the given PID file. The file contains the process ID of the
89 script. The PID file is removed when the script exits. Before
90 starting, the script checks if the PID file already exists. If it
91 does not, then the script creates and writes its own PID to it. If
92 it does, then the script checks the following: if the file contains
93 a PID and a process is running with that PID, then the script dies;
94 or, if there is no process running with that PID, then the script
95 overwrites the file with its own PID and starts; else, if the file
96 contains no PID, then the script dies.
97 --statistics
99 Print out statistics between chunks. The statistics are the number
100 of chunks, the number of lines, elapsed time, and lines per second
101 overall and during the last chunk.
102 --version
104 Show version and exit.
105
107 You can download Maatkit from Google Code at
108 <http://code.google.com/p/maatkit/>, or you can get any of the tools
109 easily with a command like the following:
110 wget http://www.maatkit.org/get/toolname
112 or
113 wget http://www.maatkit.org/trunk/toolname
114 Where "toolname" can be replaced with the name (or fragment of a name)
116 of any of the Maatkit tools. Once downloaded, they're ready to run; no
117 installation is needed. The first URL gets the latest released version
118 of the tool, and the second gets the latest trunk code from Subversion.
119
121 The environment variable "MKDEBUG" enables verbose debugging output in
122 all of the Maatkit tools:
123 MKDEBUG=1 mk-....
125
127 You need Perl, DBI, DBD::mysql, and some core packages that ought to be
128 installed in any reasonably new version of Perl.
129
131 For a list of known bugs see
132 <http://www.maatkit.org/bugs/mk-fifo-split>.
133 Please use Google Code Issues and Groups to report bugs or request
135 support: <http://code.google.com/p/maatkit/>. You can also join
136 #maatkit on Freenode to discuss Maatkit.
137 Please include the complete command-line used to reproduce the problem
139 you are seeing, the version of all MySQL servers involved, the complete
140 output of the tool when run with "--version", and if possible,
141 debugging output produced by running with the "MKDEBUG=1" environment
142 variable.
143
145 This program is copyright 2007-2011 Baron Schwartz. Feedback and
146 improvements are welcome.
147 THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
149 WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
150 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
151 This program is free software; you can redistribute it and/or modify it
153 under the terms of the GNU General Public License as published by the
154 Free Software Foundation, version 2; OR the Perl Artistic License. On
155 UNIX and similar systems, you can issue `man perlgpl' or `man
156 perlartistic' to read these licenses.
157 You should have received a copy of the GNU General Public License along
159 with this program; if not, write to the Free Software Foundation, Inc.,
160 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
161
163 Baron Schwartz
164
166 This tool is part of Maatkit, a toolkit for power users of MySQL.
167 Maatkit was created by Baron Schwartz; Baron and Daniel Nichter are the
168 primary code contributors. Both are employed by Percona. Financial
169 support for Maatkit development is primarily provided by Percona and
170 its clients.
171
173 This manual page documents Ver 1.0.7 Distrib 7540 $Revision: 7477 $.
174perl v5.36.0 2022-07-21 MK-FIFO-SPLIT(1)