[root@ufuso ~]# wget http://releases.wikimedia.org/mediawiki/1.22/mediawiki-1.22.3.tar.gz
　←　wget入力後にコピーしておいたURLを貼り付けてダウンロード
`mediawiki-1.22.3.tar.gz' に保存中

100%[======================================>] 20,794,195  3.92M/s 時間 9.8s    

2014-02-28 17:50:37 (2.02 MB/s) - `mediawiki-1.22.3.tar.gz' へ保存完了 [20794195/20794195]
　←　ダウンロード完了

[root@ufuso ~]# tar zxvf mediawiki-1.22.3.tar.gz　←　MediaWikiの展開（解凍）
mediawiki-1.22.3/
mediawiki-1.22.3/.jshintrc
mediawiki-1.22.3/COPYING
・・・
・・・
mediawiki-1.22.3/img_auth.php
mediawiki-1.22.3/index.php
mediawiki-1.22.3/thumb.php

[root@ufuso ~]# yes|cp -R mediawiki-1.22.3/* /var/www/html/mwiki/　←　mediawiki
フォルダの中身を既存フォルダに上書きコピー（/var/www/html/mwikiは例示）
cp: `/var/www/html/mwiki/COPYING' を上書きしてもよろしいですか(yes/no)? 
cp: `/var/www/html/mwiki/CREDITS' を上書きしてもよろしいですか(yes/no)?
cp: `/var/www/html/mwiki/FAQ' を上書きしてもよろしいですか(yes/no)?
・・・
・・・
cp: `/var/www/html/mwiki/thumb_handler.php' を上書きしてもよろしいですか(yes/no)? 
cp: `/var/www/html/mwiki/thumb_handler.php5' を上書きしてもよろしいですか(yes/no)? 
cp: `/var/www/html/mwiki/wiki.phtml' を上書きしてもよろしいですか(yes/no)?

[root@ufuso ~]# rm -f mediawiki-1.22.3.tar.gz　←　展開後は不要なのでダウンロード
ファイルを削除

[root@ufuso ~]# rm -fr mediawiki-1.22.3　←　展開後は不要なのでダウンロード
ファイルを削除

[root@ufuso ~]# php /var/www/html/mwiki/maintenance/update.php　←　1.22.3から1.
23.1にupgradeする際にエラーになったので追記。phpのアップデートが必要でした。失礼！
MediaWiki 1.23.1 Updater

Going to run database updates for mwiki
Depending on the size of your database this may take a while!
Abort with control-c in the next five seconds (skip this countdown with --quick) ... 0
Turning off Content Handler DB fields for this part of upgrade.
...have ipb_id field in ipblocks table.
...have ipb_expiry field in ipblocks table.
...already have interwiki table
...indexes seem up to 20031107 standards.
...hitcounter table already exists.
...have rc_type field in recentchanges table.
...index new_name_timestamp already set on recentchanges table.
...have user_real_name field in user table.
...querycache table already exists.
...objectcache table already exists.
...categorylinks table already exists.
...have pagelinks; skipping old links table updates
...il_from OK
...have rc_ip field in recentchanges table.
...index PRIMARY already set on image table.
...have rc_id field in recentchanges table.
...have rc_patrolled field in recentchanges table.
...logging table already exists.
...have user_token field in user table.
...have wl_notificationtimestamp field in watchlist table.
...watchlist talk page rows already present.
...user table does not contain user_emailauthenticationtimestamp field.
...page table already exists.
...have log_params field in logging table.
...logging table has correct log_title encoding.
...have ar_rev_id field in archive table.
...have page_len field in page table.
...revision table does not contain inverse_timestamp field.
...have rev_text_id field in revision table.
...have rev_deleted field in revision table.
...have img_width field in image table.
...have img_metadata field in image table.
...have user_email_token field in user table.
...have ar_text_id field in archive table.
...page_namespace is already a full int (int(11)).
...ar_namespace is already a full int (int(11)).
...rc_namespace is already a full int (int(11)).
...wl_namespace is already a full int (int(11)).
...qc_namespace is already a full int (int(11)).
...log_namespace is already a full int (int(11)).
...have img_media_type field in image table.
...already have pagelinks table.
...image table does not contain img_type field.
...already have unique user_name index.
...user_groups table exists and is in current format.
...have ss_total_pages field in site_stats table.
...user_newtalk table already exists.
...transcache table already exists.
...have iw_trans field in interwiki table.
...wl_notificationtimestamp is already nullable.
...index times already set on logging table.
...have ipb_range_start field in ipblocks table.
...no page_random rows needed to be set
...have user_registration field in user table.
...templatelinks table already exists
...externallinks table already exists.
...job table already exists.
...have ss_images field in site_stats table.
...langlinks table already exists.
...querycache_info table already exists.
...filearchive table already exists.
...have ipb_anon_only field in ipblocks table.
...index rc_ns_usertext already set on recentchanges table.
...index rc_user_text already set on recentchanges table.
...have user_newpass_time field in user table.
...redirect table already exists.
...querycachetwo table already exists.
...have ipb_enable_autoblock field in ipblocks table.
...index pl_namespace on table pagelinks includes field pl_from.
...index tl_namespace on table templatelinks includes field tl_from.
...index il_to on table imagelinks includes field il_from.
...have rc_old_len field in recentchanges table.
...have user_editcount field in user table.
...page_restrictions table already exists.
...have log_id field in logging table.
...have rev_parent_id field in revision table.
...have pr_id field in page_restrictions table.
...have rev_len field in revision table.
...have rc_deleted field in recentchanges table.
...have log_deleted field in logging table.
...have ar_deleted field in archive table.
...have ipb_deleted field in ipblocks table.
...have fa_deleted field in filearchive table.
...have ar_len field in archive table.
...have ipb_block_email field in ipblocks table.
...index cl_sortkey on table categorylinks includes field cl_from.
...have oi_metadata field in oldimage table.
...index usertext_timestamp already set on archive table.
...index img_usertext_timestamp already set on image table.
...index oi_usertext_timestamp already set on oldimage table.
...have ar_page_id field in archive table.
...have img_sha1 field in image table.
...protected_titles table already exists.
...have ipb_by_text field in ipblocks table.
...page_props table already exists.
...updatelog table already exists.
...category table already exists.
Populating category table, printing progress markers. For large databases, you
may want to hit Ctrl-C and do this manually with maintenance/
populateCategory.php.
Category population complete.
Done populating category table.
...have ar_parent_id field in archive table.
...have user_last_timestamp field in user_newtalk table.
Populating rev_parent_id fields, printing progress markers. For large
databases, you may want to hit Ctrl-C and do this manually with
maintenance/populateParentId.php.
Populating rev_parent_id column
...doing rev_id from 1 to 200
rev_parent_id population complete ... 0 rows [0 changed]
...protected_titles table has correct pt_title encoding.
...have ss_active_users field in site_stats table.
...ss_active_users user count set...
...have ipb_allow_usertalk field in ipblocks table.
...pl_namespace, tl_namespace, il_to indices are already UNIQUE.
...change_tag table already exists.
...tag_summary table already exists.
...valid_tag table already exists.
...user_properties table already exists.
...log_search table already exists.
...have log_user_text field in logging table.
Populating log_user_text field, printing progress markers. For large
databases, you may want to hit Ctrl-C and do this manually with
maintenance/populateLogUsertext.php.
Nothing to do.
done.
Populating log_search table, printing progress markers. For large
databases, you may want to hit Ctrl-C and do this manually with
maintenance/populateLogSearch.php.
Nothing to do.
done.
...l10n_cache table already exists.
...index ls_field_val already set on log_search table.
...index change_tag_rc_tag already set on change_tag table.
...have rd_interwiki field in redirect table.
Converting tc_time from UNIX epoch to MediaWiki timestamp ...done.
Altering all *_mime_minor fields to 100 bytes in size ...done.
...iwlinks table already exists.
...index iwl_prefix_title_from already set on iwlinks table.
...have ul_value field in updatelog table.
...have iw_api field in interwiki table.
...iwl_prefix key doesn't exist.
...have cl_collation field in categorylinks table.
Updating categorylinks (again) ...done.
...collations up-to-date.
...msg_resource table already exists.
...module_deps table already exists.
...ar_page_revid key doesn't exist.
...index ar_revid already set on archive table.
...ll_lang is up-to-date.
...user_last_timestamp is already nullable.
...index user_email already set on user table.
Modifying up_property field of table user_properties ...done.
...uploadstash table already exists.
...user_former_groups table already exists.
...index type_action already set on logging table.
...have rev_sha1 field in revision table.
...batch conversion of user_options: nothing to migrate. done.
...user table does not contain user_options field.
...have ar_sha1 field in archive table.
...index page_redirect_namespace_len already set on page table.
...have us_chunk_inx field in uploadstash table.
...have job_timestamp field in job table.
...index page_user_timestamp already set on revision table.
...have ipb_parent_block_id field in ipblocks table.
...index ipb_parent_block_id already set on ipblocks table.
...category table does not contain cat_hidden field.
...have rev_content_format field in revision table.
...have rev_content_model field in revision table.
...have ar_content_format field in archive table.
...have ar_content_model field in archive table.
...have page_content_model field in page table.
Content Handler DB fields should be usable now.
...site_stats table does not contain ss_admins field.
...recentchanges table does not contain rc_moved_to_title field.
...sites table already exists.
...have fa_sha1 field in filearchive table.
...have job_token field in job table.
...have job_attempts field in job table.
...have us_props field in uploadstash table.
Modifying ug_group field of table user_groups ...done.
Modifying ufg_group field of table user_former_groups ...done.
...index pp_propname_page already set on page_props table.
...index img_media_mime already set on image table.
...iwl_prefix_title_from index is already non-UNIQUE.
...index iwl_prefix_from_title already set on iwlinks table.
...have ar_id field in archive table.
...have el_id field in externallinks table.
Adding rc_source field to table recentchanges ...done.
Adding index log_user_text_type_time to table logging ...done.
Adding index log_user_text_time to table logging ...done.
Adding page_links_updated field to table page ...done.
Adding user_password_expires field to table user ...done.
...site_stats is populated...done.
Checking existence of old default messages...done.
Populating rev_len column
...doing rev_id from 1 to 200
Populating ar_len column
...archive table seems to be empty.
rev_len and ar_len population complete [0 revision rows, 0 archive rows].
Populating rev_sha1 column
...doing rev_id from 1 to 200
Populating ar_sha1 column
...archive table seems to be empty.
Populating ar_sha1 column legacy rows
rev_sha1 and ar_sha1 population complete [0 revision rows, 0 archive rows].
Populating img_sha1 field

Done 0 files in 0.0 seconds
Fixing protocol-relative entries in the externallinks table...
Done, 0 rows updated.
Populating fa_sha1 field from fa_storage_key

Done 0 files in 0.0 seconds
Purging caches...done.

Done in 0:03.