mk-show-grants.1p man page

mk-show-grants — Canonicalize and print MySQL grants so you can effectively replicate, compare and version-control them.


Usage: mk-show-grants [OPTION...] [DSN]

mk-show-grants shows grants (user privileges) from a MySQL server.


mk-show-grants --separate --revoke | diff othergrants.sql -


The following section is included to inform users about the potential risks, whether known or unknown, of using this tool. The two main categories of risks are those created by the nature of the tool (e.g. read-only tools vs. read-write tools) and those created by bugs.

mk-show-grants is read-only by default, and very low-risk. If you specify "--flush", it will execute "FLUSH PRIVILEGES".

At the time of this release, we know of no bugs that could cause serious harm to users.

The authoritative source for updated information is always the online issue tracking system. Issues that affect this tool will be marked as such. You can see a list of such issues at the following URL: <http://www.maatkit.org/bugs/mk-show-gra…>.

See also "Bugs" for more information on filing bugs and getting help.


mk-show-grants extracts, orders, and then prints grants for MySQL user accounts.

Why would you want this? There are several reasons.

The first is to easily replicate users from one server to another; you can simply extract the grants from the first server and pipe the output directly into another server.

The second use is to place your grants into version control. If you do a daily automated grant dump into version control, you'll get lots of spurious changesets for grants that don't change, because MySQL prints the actual grants out in a seemingly random order. For instance, one day it'll say

GRANT DELETE, INSERT, UPDATE ON `test`.* TO 'foo'@'%';

And then another day it'll say

GRANT INSERT, DELETE, UPDATE ON `test`.* TO 'foo'@'%';

The grants haven't changed, but the order has. This script sorts the grants within the line, between 'GRANT' and 'ON'. If there are multiple rows from SHOW GRANTS, it sorts the rows too, except that it always prints the row with the user's password first, if it exists. This removes three kinds of inconsistency you'll get from running SHOW GRANTS, and avoids spurious changesets in version control.

Third, if you want to diff grants across servers, it will be hard without "canonicalizing" them, which mk-show-grants does. The output is fully diff-able.

With the "--revoke", "--separate" and other options, mk-show-grants also makes it easy to revoke specific privileges from users. This is tedious otherwise.


This tool accepts additional command-line arguments. Refer to the "Synopsis" and usage information for details.

Prompt for a password when connecting to MySQL.
short form: -A; type: string

Default character set. If the value is utf8, sets Perl's binmode on STDOUT to utf8, passes the mysql_enable_utf8 option to DBD::mysql, and runs SET NAMES UTF8 after connecting to MySQL. Any other value sets binmode on STDOUT without the utf8 layer, and runs SET NAMES after connecting to MySQL.
type: Array

Read this comma-separated list of config files; if specified, this must be the first option on the command line.
short form: -D; type: string

The database to use for the connection.
short form: -F; type: string

Only read mysql options from the given file. You must give an absolute pathname.
Add DROP USER before each user in the output.
Add FLUSH PRIVILEGES after output.

You might need this on pre-4.1.1 servers if you want to drop a user completely.

default: yes

Print dump header.

The header precedes the dumped grants. It looks like:

-- Grants dumped by mk-show-grants 1.0.19
-- Dumped from server Localhost via UNIX socket, MySQL 5.0.82-log at 2009-10-26 10:01:04

See also "--[no]timestamp".

Show help and exit.
short form: -h; type: string

Connect to host.
type: array

Ignore this comma-separated list of users.
type: array

Only show grants for this comma-separated list of users.
short form: -p; type: string

Password to use when connecting.
type: string

Create the given PID file. The file contains the process ID of the script. The PID file is removed when the script exits. Before starting, the script checks if the PID file already exists. If it does not, then the script creates and writes its own PID to it. If it does, then the script checks the following: if the file contains a PID and a process is running with that PID, then the script dies; or, if there is no process running with that PID, then the script overwrites the file with its own PID and starts; else, if the file contains no PID, then the script dies.
short form: -P; type: int

Port number to use for connection.
Add REVOKE statements for each GRANT statement.
List each GRANT or REVOKE separately.

The default output from MySQL's SHOW GRANTS command lists many privileges on a single line. With "--flush", places a FLUSH PRIVILEGES after each user, instead of once at the end of all the output.
type: string; default: wait_timeout=10000

Set these MySQL variables. Immediately after connecting to MySQL, this string will be appended to SET and executed.
short form: -S; type: string

Socket file to use for connection.
default: yes

Add timestamp to the dump header.

See also "--[no]header".
short form: -u; type: string

User for login if not current user.
Show version and exit.

Dsn Options

These DSN options are used to create a DSN. Each option is given like "option=value". The options are case-sensitive, so P and p are not the same option. There cannot be whitespace before or after the "=" and if the value contains whitespace it must be quoted. DSN options are comma-separated. See the maatkit manpage for full details.


dsn: charset; copy: yes

Default character set.

dsn: database; copy: yes

Default database.

dsn: mysql_read_default_file; copy: yes

Only read default options from the given file

dsn: host; copy: yes

Connect to host.

dsn: password; copy: yes

Password to use when connecting.

dsn: port; copy: yes

Port number to use for connection.

dsn: mysql_socket; copy: yes

Socket file to use for connection.

dsn: user; copy: yes

User for login if not current user.


You can download Maatkit from Google Code at <http://code.google.com/p/maatkit/>, or you can get any of the tools easily with a command like the following:

wget http://www.maatkit.org/get/toolname
wget http://www.maatkit.org/trunk/toolname

Where "toolname" can be replaced with the name (or fragment of a name) of any of the Maatkit tools. Once downloaded, they're ready to run; no installation is needed. The first URL gets the latest released version of the tool, and the second gets the latest trunk code from Subversion.


The environment variable "MKDEBUG" enables verbose debugging output in all of the Maatkit tools:

MKDEBUG=1 mk-....

System Requirements

You need the following Perl modules: DBI and DBD::mysql.


For a list of known bugs see <http://www.maatkit.org/bugs/mk-show-gra…>.

Please use Google Code Issues and Groups to report bugs or request support: <http://code.google.com/p/maatkit/>. You can also join #maatkit on Freenode to discuss Maatkit.

Please include the complete command-line used to reproduce the problem you are seeing, the version of all MySQL servers involved, the complete output of the tool when run with "--version", and if possible, debugging output produced by running with the "MKDEBUG=1" environment variable.

Copyright, License and Warranty

This program is copyright 2007-2011 Baron Schwartz. Feedback and improvements are welcome.


This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2; OR the Perl Artistic License. On UNIX and similar systems, you can issue `man perlgpl' or `man perlartistic' to read these licenses.

You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.

See Also

Someone pointed out that this has been done before (not surprising, as it's not all that complicated). Visit <http://www.futhark.ch/mysql/139.html> for a simpler implementation of the same general concept, though without the canonicalization. I borrowed the idea of adding DROP USER from that script, and it inspired me to add the REVOKE functionality too.


Baron Schwartz

About Maatkit

This tool is part of Maatkit, a toolkit for power users of MySQL. Maatkit was created by Baron Schwartz; Baron and Daniel Nichter are the primary code contributors. Both are employed by Percona. Financial support for Maatkit development is primarily provided by Percona and its clients.


This manual page documents Ver 1.0.23 Distrib 7540 $Revision: 7477 $.