Manual:ChangePassword.php/en

Details
changePassword.php file is a maintenance script to change the password of a user on your wiki. Note that passwords must have at least 10 characters.

Usage
Usernames and passwords can have spaces, which will need to be protected from your shell (be it bash or ; see Troubleshooting, below):

Troubleshooting

 * If your MediaWiki installation uses a memory cache, such as APC, memcached or Redis, then the user object is cached. Thus after making SQL changes you must flush the cache before a user can log in with the new password.
 * Windows has special challenges with parsing double-quoted strings, as when a username or password contains spaces in the second example above.
 * Occasionally triple and quadruple sets of double quotes will solve your problems with Windows' command shell,  . You may be happier, though, to try Cygwin and follow the Unix conventions for quoting strings, which require fewer quotation marks.