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172 lines
4.8 KiB
ReStructuredText
172 lines
4.8 KiB
ReStructuredText
.. program:: pt-fifo-split
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==========================
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:program:`pt-fifo-split`
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==========================
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.. highlight:: perl
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NAME
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====
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:program:`pt-fifo-split` - Split files and pipe lines to a fifo without really splitting.
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SYNOPSIS
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========
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Usage
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-----
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::
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pt-fifo-split [options] [FILE ...]
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:program:`pt-fifo-split` splits FILE and pipes lines to a fifo. With no FILE, or when FILE is -, read standard input.
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Read hugefile.txt in chunks of a million lines without physically splitting it:
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.. code-block:: perl
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pt-fifo-split --lines 1000000 hugefile.txt
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while [ -e /tmp/pt-fifo-split ]; do cat /tmp/pt-fifo-split; done
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RISKS
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=====
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The following section is included to inform users about the potential risks,
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whether known or unknown, of using this tool. The two main categories of risks
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are those created by the nature of the tool (e.g. read-only tools vs. read-write
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tools) and those created by bugs.
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:program:`pt-fifo-split` creates and/or deletes the "--fifo" file. Otherwise, no other files are modified, and it merely reads lines from the file given on the command-line. It should be very low-risk.
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At the time of this release, we know of no bugs that could cause serious harm to
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users.
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The authoritative source for updated information is always the online issue
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tracking system. Issues that affect this tool will be marked as such. You can
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see a list of such issues at the following URL:
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`http://www.percona.com/bugs/pt-fifo-split <http://www.percona.com/bugs/pt-fifo-split>`_.
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See also "BUGS" for more information on filing bugs and getting help.
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DESCRIPTION
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===========
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:program:`pt-fifo-split` lets you read from a file as though it contains only some of the lines in the file. When you read from it again, it contains the next set of lines; when you have gone all the way through it, the file disappears. This works only on Unix-like operating systems.
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You can specify multiple files on the command line. If you don't specify any,
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or if you use the special filename \ ``-``\ , lines are read from standard input.
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OPTIONS
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=======
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This tool accepts additional command-line arguments. Refer to the
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"SYNOPSIS" and usage information for details.
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.. option:: --config
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type: Array
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Read this comma-separated list of config files; if specified, this must be the
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first option on the command line.
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.. option:: --fifo
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type: string; default: /tmp/pt-fifo-split
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The name of the fifo from which the lines can be read.
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.. option:: --force
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Remove the fifo if it exists already, then create it again.
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.. option:: --help
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Show help and exit.
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.. option:: --lines
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type: int; default: 1000
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The number of lines to read in each chunk.
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.. option:: --offset
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type: int; default: 0
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Begin at the Nth line. If the argument is 0, all lines are printed to the fifo.
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If 1, then beginning at the first line, lines are printed (exactly the same as
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0). If 2, the first line is skipped, and the 2nd and subsequent lines are
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printed to the fifo.
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.. option:: --pid
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type: string
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Create the given PID file. The file contains the process ID of the script.
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The PID file is removed when the script exits. Before starting, the script
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checks if the PID file already exists. If it does not, then the script creates
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and writes its own PID to it. If it does, then the script checks the following:
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if the file contains a PID and a process is running with that PID, then
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the script dies; or, if there is no process running with that PID, then the
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script overwrites the file with its own PID and starts; else, if the file
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contains no PID, then the script dies.
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.. option:: --statistics
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Print out statistics between chunks. The statistics are the number of chunks,
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the number of lines, elapsed time, and lines per second overall and during the
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last chunk.
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.. option:: --version
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Show version and exit.
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ENVIRONMENT
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===========
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The environment variable \ ``PTDEBUG``\ enables verbose debugging output to STDERR.
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To enable debugging and capture all output to a file, run the tool like:
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.. code-block:: perl
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PTDEBUG=1 pt-fifo-split ... > FILE 2>&1
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Be careful: debugging output is voluminous and can generate several megabytes
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of output.
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SYSTEM REQUIREMENTS
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===================
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You need Perl, DBI, DBD::mysql, and some core packages that ought to be
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installed in any reasonably new version of Perl.
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BUGS
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====
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For a list of known bugs, see `http://www.percona.com/bugs/pt-fifo-split <http://www.percona.com/bugs/pt-fifo-split>`_.
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Please report bugs at `https://bugs.launchpad.net/percona-toolkit <https://bugs.launchpad.net/percona-toolkit>`_.
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AUTHORS
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=======
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Baron Schwartz
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COPYRIGHT, LICENSE, AND WARRANTY
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================================
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This program is copyright 2007-2011 Baron Schwartz, 2011 Percona Inc.
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Feedback and improvements are welcome.
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VERSION
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=======
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:program:`pt-fifo-split` 1.0.1
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