Posts Tagged ‘system administrator’

Finding top access IPs in Webserver or how to delay connects from Bots (Web Spiders) to your site to prevent connect Denial of Service

Friday, September 15th, 2017

analyze-log-files-most-visited-ips-and-find-and-stopwebsite-hammering-bot-spiders-neo-tux

If you're a sysadmin who has to deal with cracker attemps for DoS (Denial of Service) on single or multiple servers (clustered CDN or standalone) Apache Webservers, nomatter whether working for some web hosting company or just running your private run home brew web server its very useful thing to inspect Web Server log file (in Apache HTTPD case that's access.log).

Sometimes Web Server overloads and the follow up Danial of Service (DoS) affect is not caused by evil crackers (mistkenly often called hackers but by some data indexing Crawler Search Engine bots who are badly configured to aggressively crawl websites and hence causing high webserver loads flooding your servers with bad 404 or 400, 500 or other requests, just to give you an example of such obstructive bots.

1. Dealing with bad Search Indexer Bots (Spiders) with robots.txt

Just as I mentioned hackers word above I feel obliged to expose the badful lies the press and media spreading for years misconcepting in people's mind the word cracker (computer intruder) with a hacker, if you're one of those who mistakenly call security intruders hackers I recommend you read Dr. Richard Stallman's article On Hacking to get the proper understanding that hacker is an cheerful attitude of mind and spirit and a hacker could be anyone who has this kind of curious and playful mind out there. Very often hackers are computer professional, though many times they're skillful programmers, a hacker is tending to do things in a very undstandard and weird ways to make fun out of life but definitelely follow the rule of do no harm to the neighbor.

Well after the short lirical distraction above, let me continue;

Here is a short list of Search Index Crawler bots with very aggressive behaviour towards websites:

 

# mass download bots / mirroring utilities
1. webzip
2. webmirror
3. webcopy
4. netants
5. getright
6. wget
7. webcapture
8. libwww-perl
9. megaindex.ru
10. megaindex.com
11. Teleport / TeleportPro
12. Zeus
….

Note that some of the listed crawler bots are actually a mirroring clients tools (wget) etc., they're also included in the list of server hammering bots because often  websites are attempted to be mirrored by people who want to mirror content for the sake of good but perhaps these days more often mirror (duplicate) your content for the sake of stealing, this is called in Web language Content Stealing in SEO language.


I've found a very comprehensive list of Bad Bots to block on Mike's tech blog his website provided example of bad robots.txt file is mirrored as plain text file here

Below is the list of Bad Crawler Spiders taken from his site:

 

# robots.txt to prohibit bad internet search engine spiders to crawl your website
# Begin block Bad-Robots from robots.txt
User-agent: asterias
Disallow:/
User-agent: BackDoorBot/1.0
Disallow:/
User-agent: Black Hole
Disallow:/
User-agent: BlowFish/1.0
Disallow:/
User-agent: BotALot
Disallow:/
User-agent: BuiltBotTough
Disallow:/
User-agent: Bullseye/1.0
Disallow:/
User-agent: BunnySlippers
Disallow:/
User-agent: Cegbfeieh
Disallow:/
User-agent: CheeseBot
Disallow:/
User-agent: CherryPicker
Disallow:/
User-agent: CherryPickerElite/1.0
Disallow:/
User-agent: CherryPickerSE/1.0
Disallow:/
User-agent: CopyRightCheck
Disallow:/
User-agent: cosmos
Disallow:/
User-agent: Crescent
Disallow:/
User-agent: Crescent Internet ToolPak HTTP OLE Control v.1.0
Disallow:/
User-agent: DittoSpyder
Disallow:/
User-agent: EmailCollector
Disallow:/
User-agent: EmailSiphon
Disallow:/
User-agent: EmailWolf
Disallow:/
User-agent: EroCrawler
Disallow:/
User-agent: ExtractorPro
Disallow:/
User-agent: Foobot
Disallow:/
User-agent: Harvest/1.5
Disallow:/
User-agent: hloader
Disallow:/
User-agent: httplib
Disallow:/
User-agent: humanlinks
Disallow:/
User-agent: InfoNaviRobot
Disallow:/
User-agent: JennyBot
Disallow:/
User-agent: Kenjin Spider
Disallow:/
User-agent: Keyword Density/0.9
Disallow:/
User-agent: LexiBot
Disallow:/
User-agent: libWeb/clsHTTP
Disallow:/
User-agent: LinkextractorPro
Disallow:/
User-agent: LinkScan/8.1a Unix
Disallow:/
User-agent: LinkWalker
Disallow:/
User-agent: LNSpiderguy
Disallow:/
User-agent: lwp-trivial
Disallow:/
User-agent: lwp-trivial/1.34
Disallow:/
User-agent: Mata Hari
Disallow:/
User-agent: Microsoft URL Control – 5.01.4511
Disallow:/
User-agent: Microsoft URL Control – 6.00.8169
Disallow:/
User-agent: MIIxpc
Disallow:/
User-agent: MIIxpc/4.2
Disallow:/
User-agent: Mister PiX
Disallow:/
User-agent: moget
Disallow:/
User-agent: moget/2.1
Disallow:/
User-agent: mozilla/4
Disallow:/
User-agent: Mozilla/4.0 (compatible; BullsEye; Windows 95)
Disallow:/
User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows 95)
Disallow:/
User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows 98)
Disallow:/
User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows NT)
Disallow:/
User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows XP)
Disallow:/
User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows 2000)
Disallow:/
User-agent: Mozilla/4.0 (compatible; MSIE 4.0; Windows ME)
Disallow:/
User-agent: mozilla/5
Disallow:/
User-agent: NetAnts
Disallow:/
User-agent: NICErsPRO
Disallow:/
User-agent: Offline Explorer
Disallow:/
User-agent: Openfind
Disallow:/
User-agent: Openfind data gathere
Disallow:/
User-agent: ProPowerBot/2.14
Disallow:/
User-agent: ProWebWalker
Disallow:/
User-agent: QueryN Metasearch
Disallow:/
User-agent: RepoMonkey
Disallow:/
User-agent: RepoMonkey Bait & Tackle/v1.01
Disallow:/
User-agent: RMA
Disallow:/
User-agent: SiteSnagger
Disallow:/
User-agent: SpankBot
Disallow:/
User-agent: spanner
Disallow:/
User-agent: suzuran
Disallow:/
User-agent: Szukacz/1.4
Disallow:/
User-agent: Teleport
Disallow:/
User-agent: TeleportPro
Disallow:/
User-agent: Telesoft
Disallow:/
User-agent: The Intraformant
Disallow:/
User-agent: TheNomad
Disallow:/
User-agent: TightTwatBot
Disallow:/
User-agent: Titan
Disallow:/
User-agent: toCrawl/UrlDispatcher
Disallow:/
User-agent: True_Robot
Disallow:/
User-agent: True_Robot/1.0
Disallow:/
User-agent: turingos
Disallow:/
User-agent: URLy Warning
Disallow:/
User-agent: VCI
Disallow:/
User-agent: VCI WebViewer VCI WebViewer Win32
Disallow:/
User-agent: Web Image Collector
Disallow:/
User-agent: WebAuto
Disallow:/
User-agent: WebBandit
Disallow:/
User-agent: WebBandit/3.50
Disallow:/
User-agent: WebCopier
Disallow:/
User-agent: WebEnhancer
Disallow:/
User-agent: WebmasterWorldForumBot
Disallow:/
User-agent: WebSauger
Disallow:/
User-agent: Website Quester
Disallow:/
User-agent: Webster Pro
Disallow:/
User-agent: WebStripper
Disallow:/
User-agent: WebZip
Disallow:/
User-agent: WebZip/4.0
Disallow:/
User-agent: Wget
Disallow:/
User-agent: Wget/1.5.3
Disallow:/
User-agent: Wget/1.6
Disallow:/
User-agent: WWW-Collector-E
Disallow:/
User-agent: Xenu’s
Disallow:/
User-agent: Xenu’s Link Sleuth 1.1c
Disallow:/
User-agent: Zeus
Disallow:/
User-agent: Zeus 32297 Webster Pro V2.9 Win32
Disallow:/
Crawl-delay: 20
# Begin Exclusion From Directories from robots.txt
Disallow: /cgi-bin/

Veryimportant variable among the ones passed by above robots.txt is
 

Crawl-Delay: 20

 


You might want to tune that variable a Crawl-Delay of 20 instructs all IP connects from any Web Spiders that are respecting robots.txt variables to delay crawling with 20 seconds between each and every connect client request, that is really useful for the Webserver as less connects means less CPU and Memory usage and less degraded performance put by aggressive bots crawling your site like crazy, requesting resources 10 times per second or so …

As you can conclude by the naming of some of the bots having them disabled would prevent your domain/s clients from Email harvesting Spiders and other not desired activities.


 

2. Listing IP addresses Hits / How many connects per IPs used to determine problematic server overloading a huge number of IPs connects

After saying few words about SE bots and I think it it is fair to also  mention here a number of commands, that helps the sysadmin to inspect Apache's access.log files.
Inspecting the log files regularly is really useful as the number of malicious Spider Bots and the Cracker users tends to be
raising with time, so having a good way to track the IPs that are stoning at your webserver and later prohibiting them softly to crawl either via robots.txt (not all of the Bots would respect that) or .htaccess file or as a last resort directly form firewall is really useful to know.
 

– Below command Generate a list of IPs showing how many times of the IPs connected the webserver (bear in mind that commands are designed log fields order as given by most GNU / Linux distribution + Apache default logging configuration;

 

webhosting-server:~# cd /var/log/apache2 webhosting-server:/var/log/apache2# cat access.log| awk '{print $1}' | sort | uniq -c |sort -n


Below command provides statistics info based on whole access.log file records, sometimes you will need to have analyzed just a chunk of the webserver log, lets say last 12000 IP connects, here is how:
 

webhosting-server:~# cd /var/log/apache2 webhosting-server:/var/log/apache2# tail -n 12000 access.log| awk '{print $1}' | sort | uniq -c |sort -n


You can combine above basic bash shell parser commands with the watch command to have a top like refresh statistics every few updated refreshing IP statistics of most active customers on your websites.

Here is an example:

 

webhosting-server:~# watch "cat access.log| awk '{print $1}' | sort | uniq -c |sort -n";

 


Once you have the top connect IPs if you have a some IP connecting with lets say 8000-10000 thousand times in a really short interval of time 20-30 minues or so. Hence it is a good idea to investigate further where is this IP originating from and if it is some malicious Denial of Service, filter it out either in Firewall (with iptables rules) or ask your ISP or webhosting to do you a favour and drop all the incoming traffic from that IP.

Here is how to investigate a bit more about a server stoner IP;
Lets assume that you found IP: 176.9.50.244 to be having too many connects to your webserver:
 

webhosting-server:~# grep -i 176.9.50.244 /var/log/apache2/access.log|tail -n 1
176.9.50.244 – – [12/Sep/2017:07:42:13 +0300] "GET / HTTP/1.1" 403 371 "-" "Mozilla/5.0 (compatible; MegaIndex.ru/2.0; +http://megaindex.com/crawler)"

 

webhosting-server:~# host 176.9.50.244
244.50.9.176.in-addr.arpa domain name pointer static.244.50.9.176.clients.your-server.de.

 

webhosting-server:~# whois 176.9.50.244|less

 

The outout you will get would be something like:

% This is the RIPE Database query service.
% The objects are in RPSL format.
%
% The RIPE Database is subject to Terms and Conditions.
% See http://www.ripe.net/db/support/db-terms-conditions.pdf

% Note: this output has been filtered.
%       To receive output for a database update, use the "-B" flag.

% Information related to '176.9.50.224 – 176.9.50.255'

% Abuse contact for '176.9.50.224 – 176.9.50.255' is 'abuse@hetzner.de'

inetnum:        176.9.50.224 – 176.9.50.255
netname:        HETZNER-RZ15
descr:          Hetzner Online GmbH
descr:          Datacenter 15
country:        DE
admin-c:        HOAC1-RIPE
tech-c:         HOAC1-RIPE
status:         ASSIGNED PA
mnt-by:         HOS-GUN
mnt-lower:      HOS-GUN
mnt-routes:     HOS-GUN
created:        2012-03-12T09:45:54Z
last-modified:  2015-08-10T09:29:53Z
source:         RIPE

role:           Hetzner Online GmbH – Contact Role
address:        Hetzner Online GmbH
address:        Industriestrasse 25
address:        D-91710 Gunzenhausen
address:        Germany
phone:          +49 9831 505-0
fax-no:         +49 9831 505-3
abuse-mailbox:  abuse@hetzner.de
remarks:        *************************************************
remarks:        * For spam/abuse/security issues please contact *
remarks:        * abuse@hetzner.de, not this address. *
remarks:        * The contents of your abuse email will be *
remarks:        * forwarded directly on to our client for *
….


3. Generate list of directories and files that are most called by clients
 

webhosting-server:~# cd /var/log/apache2; webhosting-server:/var/log/apache2# awk '{print $7}' access.log|cut -d? -f1|sort|uniq -c|sort -nk1|tail -n10

( take in consideration that this info is provided only on current records from /var/log/apache2/ and is short term for long term statistics you have to merge all existing gzipped /var/log/apache2/access.log.*.gz )

To merge all the old gzipped files into one single file and later use above shown command to analyize run:

 

cd /var/log/apache2/
cp -rpf *access.log*.gz apache-gzipped/
cd apache-gzipped
for i in $(ls -1 *access*.log.*.gz); do gzip -d $i; done
rm -f *.log.gz;
for i in $(ls -1 *|grep -v access_log_complete); do cat $i >> access_log_complete; done


Though the accent of above article is Apache Webserver log analyzing, the given command examples can easily be recrafted to work properly on other Web Servers LigHTTPD, Nginx etc.

Above commands are about to put a higher load to your server during execution, so on busy servers it is a better idea, to first go and synchronize the access.log files to another less loaded servers in most small and midsized companies this is being done by a periodic synchronization of the logs to the log server used usually only to store log various files and later used to do various analysis our run analyse software such as Awstats, Webalizer, Piwik, Go Access etc.

Worthy to mention one great text console must have Apache tool that should be mentioned to analyze in real time for the lazy ones to type so much is Apache-top but those script will be not installed on most webhosting servers and VPS-es, so if you don't happen to own a self-hosted dedicated server / have webhosting company etc. – (have root admin access on server), but have an ordinary server account you can use above commands to get an overall picture of abusive webserver IPs.

logstalgia-visual-loganalyzer-in-reali-time-windows-linux-mac
 

If you have a Linux with a desktop GUI environment and have somehow mounted remotely the weblog server partition another really awesome way to visualize in real time the connect requests to  web server Apache / Nginx etc. is with Logstalgia

Well that's all folks, I hope that article learned you something new. Enjoy

Thanks for article neo-tux picture to segarkshtri.com.np)

Windows key Shortcuts and Commands List every Win admin / support must know

Tuesday, November 25th, 2014

windows-XP-vista-7-8-server-2003-rc2-2012--full-complete-keyboard-shortcuts-list
If you're a system administrator of Windows Servers or or just a PC support in a small company and you have to fix PCs running Microsoft Windows XP / 7 / 8  daily, sooner or later you will be interested into how to optimize your windows maintainance work to be able to do more adminsitration work for less time.

M$ Windows OS has evolved a lot over the past 10+ years and many of the features available GUI are now either possibile to be done via a standard commands and the GUI interfaces. Various adminsitration and common daily work simplification goodies are now accessible through quick access shortcuts and commands.

Virtually all Windows operating system environment could be now customized by using such shortcuts, this reduces the multitude of annoying double clicks which are truely pissing off sysadmins and tech-supports involved in  Windows Ticket solving.

Win Shortcuts and Commands helps to:

  • Quickly invoke almost all System Settings available from Windows Control Panel
  • Access all admins tools GUIs throguh command
  • Speed up Opening Video, Pictures, Documents, Downloads folders start Windows Update, Configure Printers / Fax / Add Sharings

etc..

A lot of the commands were new to me thus I decided to try out all of the commands in command prompt (cmd). Many of the tools down-mentioned were news to me and let me understand better on Windows Internals, so if you time try them out.
 

Function Comand
Open Documents Folder Start menu -> Search (Type documents)
Open Videos folder Start -> Search (Type videos)
Open Downloads Folder Start -> Search (Type downloads)
Open Favorites Folder favorites
View Recent messages of your PC Start menu -> Search (Type recent)
Open Recent Folder N/A
Open Pictures Folder Start menu -> Search (Type pictures)
Windows Sideshow control.exe /name Microsoft.WindowsSideshow
Windows CardSpace (Windows ID Manager) control.exe /name Microsoft.cardspace
Windows Anytime Upgrade Start menu -> Search dialog (Type WindowsUpdate)
Taskbar and Start Menu control.exe /name Microsoft.TaskbarandStartMenu
Troubleshooting control.exe /name Microsoft.Troubleshooting
User Accounts (Run user accounts Interface) control.exe /name Microsoft.UserAccounts
Adding a new Device devicepairingwizard
Add Hardware Wizard hdwwiz
Advanced User Accounts Management netplwiz
Advanced User Accounts (Authorization Mgr) azman.msc
Windows Backup and Restore sdclt
Bluetooth File Transfer fsquirt
Calculator calc
Certificates Manager certmgr.msc
Change Computer Performance Settings systempropertiesperformance (Remove visual effects)
Change Data Execution Prevention Settings systempropertiesdataexecutionprevention
Change Data Execution Prevention Settings printui
Character Map charmap
ClearType Tuner cttune (Make text onscreen more readable)
Color Management colorcpl
Command Prompt cmd
Component Services comexp.msc
Component Services dcomcnfg
Computer Management Interface compmgmt.msc
Computer Management Interface compmgmtlauncher
Connect to Network Project via Network netproj
Connect to a Projector displayswitch (Alias for Fn key + F4)
Run Control Panel command control
Create A Shared Folder Wizard shrpubw
Create a System Repair Disc recdisc
Credential Backup and Restore Wizard credwiz
Data Execution Prevention systempropertiesdataexecutionprevention
Date and Time timedate.cpl
Default Location locationnotifications
Device Manager devmgmt.msc
Device Manager hdwwiz.cpl
Device Pairing Wizard devicepairingwizard
Diagnostics Troubleshooting Wizard msdt
Digitizer Calibration Tool tabcal
DirectX Diagnostic Tool dxdiag
Disk Cleanup cleanmgr
Disk Defragmenter dfrgui
Disk Management diskmgmt.msc
Display (Change font size of text onscreen) dpiscaling
Display Color Calibration dccw
Display Switch displayswitch
DPAPI Key Migration Wizard dpapimig
Driver Verifier Manager verifier
Ease of Access Center utilman
EFS Wizard rekeywiz
Event Viewer eventvwr.msc
Fax Cover Page Editor fxscover
File Signature Verification sigverif
Font Viewer fontview
Game Controllers joy.cpl
Windows Getting Started Iface gettingstarted
IExpress Wizard iexpress
Another alias for Getting Started irprops.cpl
Install or Uninstall Display Languages lusrmgr
Internet Explorer iexplore
Run Internet Explorer Internet Options inetcpl.cpl
iSCSI Initiator Configuration Tool iscsicpl
Language Pack Installer lpksetup
Local Group Policy Editor gpedit.msc
Local Security Policy secpol.msc
Local Users and Groups lusrmgr.msc
Location Activity locationnotifications
Magnifier magnify
Malicious Software Removal Tool mrt (Might be not existent on some Windows versions)
Manage Your File Encryption Certificates rekeywiz
Math Input Panel mip
Microsoft Management Console mmc
Microsoft Support Diagnostic Tool msdt
Mouse main.cpl
NAP Client Configuration napclcfg.msc
Narrator narrator
Network Connections ncpa.cpl
New Scan Wizard wiaacmgr
Notepad notepad
ODBC Data Source Administrator odbcad32
ODBC Driver Configuration odbcconf
On-Screen Keyboard osk
Paint mspaint
Pen and Touch tabletpc.cpl
People Near Me collab.cpl
Performance Monitor perfmon.msc
Performance Options systempropertiesperformance
Phone and Modem telephon.cpl
Phone Dialer dialer
Power Options powercfg.cpl
Presentation Settings presentationsettings
Print Management printmanagement.msc
Printer Migration printbrmui
Printer User Interface printui
Private Character Editor eudcedit
Problem Steps Recorder psr
Programs and Features (Install / Uninstall) appwiz.cpl
Protected Content Migration dpapimig
Region and Language intl.cpl
Registry Editor regedit
Registry Editor 32 regedt32
Remote Access Phonebook rasphone
Remote Desktop Connection mstsc
Resource Monitor resmon
Resultant Set of Policy rsop.msc
SAM Lock Tool syskey
Screen Resolution desk.cpl
Securing the Windows Account Database syskey
Services services.msc
Set Program Access and Computer Defaults computerdefaults
Share Creation Wizard shrpubw
Shared Folders fsmgmt.msc
Snipping Tool snippingtool
Sound mmsys.cpl
Sound recorder soundrecorder
SQL Server Client Network Utility cliconfg
Sticky Notes stikynot
Stored User Names and Passwords credwiz
Sync Center mobsync
System Configuration msconfig
System Configuration Editor sysedit
System Information msinfo32
System Properties sysdm.cpl
System Properties (Advanced Tab) systempropertiesadvanced
System Properties (Computer Name Tab) systempropertiescomputername
System Properties (Hardware Tab) systempropertieshardware
System Properties (Remote Tab) systempropertiesremote
System Properties (System Protection Tab) systempropertiesprotection
System Restore rstrui
Task Manager taskmgr
Task Scheduler taskschd.msc
Trusted Platform Module (TPM) Management tpm.msc
User Account Control Settings useraccountcontrolsettings
Utility Manager utilman
Version Reporter Applet winver
Volume Mixer sndvol
Windows Action Center wscui.cpl
Windows Activation Client slui (Runs on Windows license activation time)
Windows Anytime Upgrade Results windowsanytimeupgraderesults
Windows CardSpace infocardcpl.cpl
Windows Disc Image Burning Tool isoburn (Command line tool to burn images)
Windows DVD Maker dvdmaker (N/A on Windows 7, 8)
Windows Easy Transfer migwiz (N/A on many Windows versions)
Run Windows Explorer explorer
Windows Fax and Scan wfs
Windows Features optionalfeatures
Windows Firewall firewall.cpl
Windows Firewall with Advanced Security wf.msc
Windows Journal journal (N/A on Windows 7)
Windows Media Player wmplayer (N/A on many Windows releases)
Windows Memory Diagnostic Scheduler mdsched (Check your PC memory on next boot)
Windows Mobility Center (Stats) mblctr
Windows Picture Acquisition Wizard wiaacmgr
Windows PowerShell powershell
Windows PowerShell ISE powershell_ise
Windows Remote Assistance msra
Windows Repair Disc recdisc
Windows Script Host wscript
Windows Update wuapp
Windows Update Standalone Installer wusa
Show Windows Version winver
WMI Management wmimgmt.msc
WordPad write
XPS Viewer xpsrchvw


Most of above commands works fine with Windows XP, Vista and Windows 7 / 8, Windows 2003 / 2012, however some cmds are missing across some win versions.

Here is list of other useful Windows shortcut keys:
 

General keyboard shortcuts

  • Ctrl+C (Copy)
  • Ctrl+X (Delete selected item and save a copy to the clipboard)
  • Ctrl+V (Paste)
  • Ctrl+Z (Undo)
  • Delete (Delete) 
  • Shift+Delete (Delete the selected item permanently without moving the item to the Recycle Bin) 
  • Ctrl while dragging an item (Copy the selected item)
  • Ctrl+Shift while dragging an item (Create a shortcut to the selected item)
  • F2 key (Rename the selected item)
  • Ctrl+Right Arrow (Move the cursor to the beginning of the next word) 
  • Ctrl+Left Arrow (Move the cursor to the beginning of the previous word) 
  • Ctrl+Down Arrow (Move the cursor to the beginning of the next paragraph) 
  • Ctrl+Up Arrow (Move the cursor to the beginning of the previous paragraph) 
  • Ctrl+Shift with any arrow key (Highlight a block of text) 
  • Shift with any arrow key (Select more than one item in a window or on the desktop, or select text in a document) 
  • Ctrl+A (Select all) 
  • F3 key (Search for a file or a folder)
  • Alt+Enter (View the properties for the selected item) 
  • Alt+F4 (Close the active item, or exit the active program) 
  • Alt+Enter (Display the properties of the selected object) 
  • Alt+Spacebar (Open the shortcut menu for the active window) 
  • Ctrl+F4 (Close the active document in programs that enable multiple documents to be open at the same time) 
  • Alt+Tab (Switch between the open items) 
  • Alt+Esc (Cycle through items in the order in which they were opened) 
  • F6 key (Cycle through the screen elements in a window or on the desktop)
  • F4 key (Display the Address bar list in My Computer or in Windows Explorer) 
  • Shift+F10 (Display the shortcut menu for the selected item)
  • Alt+Spacebar (Display the System menu for the active window) 
  • Ctrl+Esc (Display the Start menu) 
  • Alt+Underlined letter in a menu name (Display the corresponding menu)
  • Underlined letter in a command name on an open menu (Perform the corresponding command)
  • F10 key (Activate the menu bar in the active program)
  • Right Arrow  (Open the next menu to the right, or open a submenu)
  • Left Arrow  (Open the next menu to the left, or close a submenu)
  • F5 key (Update the active window)
  • Backspace (View the folder one level up in My Computer or Windows Explorer) 
  • Esc (Cancel the current task)
  • Shift when you insert a CD into the CD drive (Prevent the CD from automatically playing)
  • Ctrl+Shift+Esc (Open Task Manager) 

Dialog box keyboard shortcuts

  • Ctrl+Tab (Move forward through the tabs)
  • Ctrl+Shift+Tab (Move backward through the tabs)
  • Tab (Move forward through the options)
  • Shift+Tab (Move backward through the options)
  • Alt+Underlined letter (Perform the corresponding command, or select the corresponding option)
  • Enter (Perform the command for the active option or button)
  • Spacebar (Select or clear the check box if the active option is a check box)
  • Arrow keys (Select a button if the active option is a group of option buttons)
  • F1 key (Display Help)
  • F4 key (Display the items in the active list)
  • Backspace (Open a folder one level up if a folder is selected in the Save As or Open dialog box)

Microsoft natural keyboard shortcuts

  • Windows Logo (Display or hide the Start menu)
  • Windows Logo+Break (Display the System Properties dialog box)
  • Windows Logo+D (Display the desktop)
  • Windows Logo+M (Minimize all the windows)
  • Windows Logo+Shift+M (Restore the minimized windows)
  • Windows Logo+E (Open My Computer)
  • Windows Logo+F (Search for a file or a folder)
  • Ctrl+Windows Logo+F (Search for computers)
  • Windows Logo+F1 (Display Windows Help)
  • Windows Logo+ L (Lock the keyboard)
  • Windows Logo+R (Open the Run dialog box)
  • Windows Logo+U (Open Utility Manager)

Accessibility keyboard shortcuts

  • Right Shift for eight seconds (Switch FilterKeys on or off)
  • Left Alt+left Shift+Print Screen (Switch High Contrast on or off)
  • Left Alt+left Shift+Num Lock (Switch the MouseKeys on or off)
  • Shift five times (Switch the StickyKeys on or off)
  • Num Lock for five seconds (Switch the ToggleKeys on or off)
  • Windows Logo +U (Open Utility Manager)

Windows Explorer keyboard shortcuts

 

 

  • End (Display the bottom of the active window)
  • Home (Display the top of the active window)
  • Num Lock+Asterisk sign (*) (Display all the subfolders that are under the selected folder)
  • Num Lock+Plus sign (+) (Display the contents of the selected folder)
  • Num Lock+Minus sign (-) (Collapse the selected folder)
  • Left Arrow  (Collapse the current selection if it is expanded, or select the parent folder)
  • Right Arrow  (Display the current selection if it is collapsed, or select the first subfolder) 

Keyboard Shortcuts for Character Map

 

 

After you double-click a character on the grid of characters, you can move through the grid by using the keyboard shortcuts:

  • Right Arrow  (Move to the right or to the beginning of the next line)
  • Left Arrow  (Move to the left or to the end of the previous line) 
  • Up Arrow (Move up one row)
  • Down Arrow (Move down one row)
  • Page Up  (Move up one screen at a time)
  • Page Down (Move down one screen at a time)
  • Home (Move to the beginning of the line)
  • End (Move to the end of the line)
  • Ctrl+Home (Move to the first character)
  • Ctrl+End (Move to the last character)
  • Spacebar (Switch between Enlarged and Normal mode when a character is selected) 

Microsoft Management Console (MMC) main window keyboard shortcuts

 

 

  • Ctrl+O (Open a saved console)
  • Ctrl+N (Open a new console)
  • Ctrl+S (Save the open console)
  • Ctrl+M (Add or remove a console item)
  • Ctrl+W (Open a new window)
  • F5 key (Update the content of all console windows)
  • Alt+Spacebar (Display the MMC window menu)
  • Alt+F4 (Close the console)
  • Alt+A (Display the Action menu)
  • Alt+V (Display the View menu)
  • Alt+F (Display the File menu)
  • Alt+O (Display the Favorites menu) 

Microsoft Management Console (MMC) window keyboard shortcuts

  • Ctrl+P (Print the current page or active pane)
  • Alt+Minus sign (-) (Display the window menu for the active console window)
  • Shift+F10 (Display the Action shortcut menu for the selected item)
  • F1 key (Open the Help topic, if any, for the selected item)
  • F5 key (Update the content of all console windows)
  • Ctrl+F10 (Maximize the active console window)
  • Ctrl+F5 (Restore the active console window)
  • Alt+Enter (Display the Properties dialog box, if any, for the selected item)
  • F2 key (Rename the selected item)
  • Ctrl+F4 (Close the active console window. When a console has only one console window, this shortcut closes the console)

Remote desktop connection navigation

 

 

  • Ctrl+Alt+End (Open the Microsoft Windows NT Security dialog box)
  • Alt+Page Up (Switch between programs from left to right)
  • Alt+Page Down (Switch between programs from right to left)
  • Alt+Insert (Cycle through the programs in most recently used order)
  • Alt+Home (Display the Start menu)
  • Ctrl+Alt+Break (Switch the client computer between a window and a full-screen display)
  • Alt+Delete (Display the Windows menu)
  • Ctrl+Alt+Minus sign (-) (Put a snapshot of the complete client window area on the Terminal server clipboard and provide the same functionality as pressing Alt+Print Screen on a local computer)
  • Ctrl+Alt+Plus sign (+) (Put a snapshot of the active window in the client on the Terminal server clipboard and provide the same functionality as pressing Print Screen on a local computer.) 

Microsoft Internet Explorer navigation

 

 

  • Ctrl+B (Open the Organize Favorites dialog box)
  • Ctrl+E (Open the Search bar)
  • Ctrl+F (Start the Find utility)
  • Ctrl+H (Open the History bar)
  • Ctrl+I (Open the Favorites bar)
  • Ctrl+L (Open the Open dialog box)
  • CtrlL+N (Start another instance of the browser with the same web address)
  • Ctrl+O (Open the Open dialog box, the same as CTRL+L)
  • Ctrl+P (Open the Print dialog box)
  • Ctrl+R (Update the current webpage)
  • Ctrl+W (Close the current window) 

Complete list of Windows Keyboard Shorcuts is on Microsoft website

Quitting my job as IT Manager and moving to Further Horizons in Hewlett Packard

Friday, September 13th, 2013

International University College Logo IUC

I haven't blogged for a while for a plenty of reasons, I'm going through a change period in my life and as any change it is not easy.
This post will be not informative and will not teach any of my dear readers, anything on Computers its pretty personal but still for my friends it might cause interest.
Here is my personal life story over the last few months …

For a while I worked in a International University College situated in my hometown Dobrich. I was hired on position of IT Manager, and actually was doing a bit of E-Marketing to try to boost traffic to College's website – www.vumk.eu and mostly helping the old school hacker ad college system administrator over the last 10 yrs – Ertan to fix a bunch of Linux Mail / SQL and Webservers and some Windows machines. In college I learned from Ertan how to install and backups of restaurants software called BARBEQUE as well as how to fix problems with billing terminals situated in College Restaurant (3rd floor of building). Other of my work time I had to  fix infested Windows computers with viruses re-install Windowses and fix various printing and network problems of College's teachers, accountants, cash desk, marketing and rest of college  employees.

Talking about Ertan I should express my sincere tremendous Thanks (Thanks Ertan) to it for recommending me for this job position. Right before I started work in the college I was jobless for a while starting to get desperate that its impossible find work. Current IUC sysadmin – Mr. Ertan Geldiev is a remarkable man and one of the people that made great impression in my mind. Something I found interesting I can learn from Ertan was to get from his cheerful "admin" attitude. As a true hacker Ertan had this hacker attitude of playfulness I myself has for a while lost over the years. So seeing someone like this near my life make me a good favor and had a positive influence on myself.

I have learned a lot from Ertan during the 3 months and 3 days in International University College. Just for a bit of historic information earlier IUC was known as International College – Albena, also among Dobrich citizens known as The Dutch College – as earlier IUC had good relations with Dutch Universities and was issuing double degrees both Bulgarian and Dutch. Nowadays I'm not sure if still Double-degrees partnership between IUC and Dutch Universities exist, what I know for sure is college is issuing European Double Degrees in partnership with Cardiff Metropolitan University. I myself have earlier studied in the college and already know the place well thus will use this post to say a few words on my impressions on it …

International University College - one of top prestigious colleges in Eastern Europe

The college is a great place to be as you have chance to meet plenty of people both lecturers (professors), participate in the various events organized by College's as well as get involved in the many European Projects which are being handled by a European Projects department special department situated on the back of the College Building. Other positive about College is it is small and located on a peaceful town of Dobrich. This gives the bright people a lot of space for personal development, anyways on the other hand it can make you also a bad as Dobrich as a small city is a bit boring. The studies in College are good for students who want personal freedom as there is not too strict requirements for professors on how to teach.

Though college had help me grow, especially in my knowledge in Windows 7 and 8 (Ertan had a really good Windows background), I couldn't have the chance to develop myself too further in the long term. So my job offer to work in HP as Web and Middleware Implementation Engineer opened much broader opportunities for my long term IT career. Other reason I quit the College IT job was simply because I needed more money I had the vision to make a family with a girl from Belarus – Svetlana and in order to take care for her I need to earn good money. My official salary in the college was the funny for the position – 640 lv (though after a few months I was promised to have a raise and earn 400 EUR :)) . Such low sallary was for the reason I had the idea to continue studying in College and complete my Bachelor Business degree and we had agreed with the College CEO Mr. Todor Radev to extract part of my salary monthly and with that to pay my 1 semester tuition fee (2200 EUR) – necessary for my graduation assignment. Though completing the Bachelor is important phase to close in my life for a long time, I found for the moment more valuable to work for HP and earn normal living salary with which to possibly finance myself and create family with woman of my life (hopefully) in the short term.

In this post I want express my sincere thanks to all people in International College (Elena Urchenko, Krasimir – for helping me in my job duties), Pavel and Silvia for being a colleague for a while I worked partly in the Marketing Department.

Talking about Marketing Department what I did there is some Twitter Marketing (building some twitter followers) and wrote a tiny document with recommendation on how to optimize College website – vumk.eu (future version) – for better SEO ranking. This included complete analysis from user outlook to Indexing bots and site current code. 

Mr Docent Phd Todor Radev

I have to do a big underline on how great person the College President and UNI Rector – Docent Todor Radev is. I have already bitter experience studying for a while in a government universities when younger and I know from experience usually Rectors and Universities management of state universities is pure "Hell". Thanks to Mr. Todor Radev for he did me a big favor letting me quit  job just a week later (instead of 1 month as it is officially set by Bulgarian Dismissal Law and explicitly stated in my Work Contract. Also as a person my experience from Docent Radev is wonderful too. He is extremely intelligent, brilliant gentleman and  most importantly open minded and always open for innovation.
 

As a close up I would like to say Big Thanks to everyone which I worked with or met in International University College! Thanks guys for all your support and help, thanks for being work mates and friends for the time.

Linux: Configure Midnight Commander to use mcedit instead of nano or vi text editor

Friday, June 21st, 2013

reverting mc text editor to mcedit fix problem with mcedit not working in linux

I use Midnight Commander console file manager on any UNIX like servers, since my early days as system administrator. mc comes with its own text editor mcedit which is often very handy for reading config files or pieces of source code. Many times I had to modify files which were spitting errors which I couldn't track in VIM, jor or whatever text editor had on server at hand and after checking file with mcedit I caught my config or source code mistake. I guess many other admins has similar nice experiences with mcedit Internal file editor of GNU Midnight Commander. Nowadays, I install mostly Debian Linux on new configured servers and using mc to navigate in file system is very useful. I prefer mc to open files for edit with F4 (Edit – kbd shortcut) with its default mcedit, however for some reasons most of Debian / Ubuntu and other Linuxes, nowadays has set global environment text editor to nano. I totally dislike this text editor and like changing mc always to use mcedit. This is done straight from MC menus by:

Pressing F9 -> Going to Options -> Configuration -> (Setting mark on) -> Use Inernal Edit
/code>

unix terminal file manager midnight commander configuration menu screenshot

linux console file manager midnight commander use internal edit menu unchecked screenshot

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Remote Desktop client – Remmina, Connect Remote to MS Windows VNC hosts from Linux

Friday, May 31st, 2013

remmina remote connet to windows linux vnc client logo

If you're system administrator, who use Linux as Desktop. You surely want to check out Remmina – The GTK+ Remote Desktop Client.

As far as I tested among all VNC Linux clients I know Remmina is definitely the one of choice in terms of Interface simplicity / stability and remote connection level of responsibility.

Before finding out about Remmina existence, I tried xtightvncviewer, xvnc4viewer, gvncviewer, gtkvncviewer. xtightvncviewer, xvncviewer and gvncviewer are more for console geeks and hence either they lack GUI interface or user interface looks terrible.

GTKVncViewer's interface is also not bad but still not со nice as Remmina's.

gtkvncviewer Debian GNU Linux Wheezy screenshot Linux VNC simple client

As you see in above shot, gtkvncviewer lacks any configuration. The only thing it can do is connect to remote host and you have option to configure nothing related how remote connection will respond, what type of Resolution to use etc.

I know of of no other Linux VNC Clients that has configurability and GUI interface of Remmina.

 

As of time of writting Remmina is at stable version 1.0 and supports following Remote connection protocols:

  • VNC
  • VNC
  • RDP
  • RDPF
  • RDPS
  • SFTP
  • SSH

Remmina is available across mostly all Linux mainstream distributions:

To install Remmina on Debian / Ubuntu and deb derivatives:

debian:~# apt-get –yes install remmina
….

On Redhats (Fedora, CentOS, RHEL – RPM based Linuxes) install via:

[root@centos ~]# yum –yes install remmina

Below are few screenshots of Remmina:

Remmina Linux remote vnc connect best software gui frontend screenshot

Linux VNC best VNC connect tool Remmina preferences screenshot

One of best Remmina feature is it supports Tabbing just like in Firefox. You can open a number of Remote VNC connects to different Windows hosts and manage them all by switching from tab to tab.

Remmina best vnc linux desktop client screenshot with tabs / What is best VNC client for Linux

Linux: Delete empty lines from text file with sed, awk, grep and vim

Saturday, March 23rd, 2013

As a system administrator, sometimes is necessary to do basic plain text processing for various sysadmin tasks. One very common task I do to remove empty lines in file. There are plenty of ways to do it i.e. – with grep, sed, awk, bash, perl etc.

1. Deleting empty file lines with sed

The most standard way to do it is with sed, as sed was written to do in shell quick regexp. Here is how;

sed '/^\s*$/d' file_with_empty_lines.txt > output_no_empty_lines.txt

2. Deleting empty file lines with awk

It is less of writting with awk, but I always forget the syntax and thus I like more sed, anyways here is how with awk;

cat file_with_empty_lines.txt | awk 'NF' >
output_no_empty_lines.txt

3. Deleting empty lines with grep

Grep  regular expression can be used. Here is grep cmd to cut off empty lines from file;

grep -v '^\s*$' file_with_empty_lines.txt >
output_no_empty_lines.txt

4. Delete empty files with vi / vim text editor

Open vi / vim text editor

$ vim

Press Esc+: and if empty lines doesn't have empty space characters use command

g/^$/d

Whether, empty lines contain " " – space characters (which are not visible in most text editors), use vi cmd:
g/^ $/d

How to count lines of PHP source code in a directory (recursively)

Saturday, July 14th, 2012

Count PHP and other programming languages lines of source code (source code files count) recursively

Being able to count the number of PHP source code lines for a website is a major statistical information for timely auditting of projects and evaluating real Project Managment costs. It is inevitable process for any software project evaluation to count the number of source lines programmers has written.
In many small and middle sized software and website development companies, it is the system administrator task to provide information or script quickly something to give info on the exact total number of source lines for projects.

Even for personal use out of curiousity it is useful to know how many lines of PHP source code a wordpress or Joomla website (with the plugins) contains.
Anyone willing to count the number of PHP source code lines under one directory level, could do it with:::

serbver:~# cd /var/www/wordpress-website
server:/var/www/wordpress-website:# wc -l *.php
17 index.php
101 wp-activate.php
1612 wp-app.php
12 wp-atom.php
19 wp-blog-header.php
105 wp-comments-post.php
12 wp-commentsrss2.php
90 wp-config-sample.php
85 wp-config.php
104 wp-cron.php
12 wp-feed.php
58 wp-links-opml.php
59 wp-load.php
694 wp-login.php
236 wp-mail.php
17 wp-pass.php
12 wp-rdf.php
15 wp-register.php
12 wp-rss.php
12 wp-rss2.php
326 wp-settings.php
451 wp-signup.php
110 wp-trackback.php
109 xmlrpc.php
4280 total

This will count and show statistics, for each and every PHP source file within wordpress-website (non-recursively), to get only information about the total number of PHP source code lines within the directory, one could grep it, e.g.:::

server:/var/www/wordpress-website:# wc -l *.php |grep -i '\stotal$'
4280 total

The command grep -i '\stotal$' has \s in beginning and $ at the end of total keyword in order to omit erroneously matching PHP source code file names which contain total in file name; for example total.php …. total_blabla.php …. blabla_total_bla.php etc. etc.

The \s grep regular expression meaning is "put empty space", "$" is placed at the end of tital to indicate to regexp grep only for words ending in string total.

So far, so good … Now it is most common that instead of counting the PHP source code lines for a first directory level to count complete number of PHP, C, Python whatever source code lines recursively – i. e. (a source code of website or projects kept in multiple sub-directories). To count recursively lines of programming code for any existing filesystem directory use find in conjunction with xargs:::

server:/var/www/wp-website1# find . -name '*.php' | xargs wc -l
1079 ./wp-admin/includes/file.php
2105 ./wp-admin/includes/media.php
103 ./wp-admin/includes/list-table.php
1054 ./wp-admin/includes/class-wp-posts-list-table.php
105 ./wp-admin/index.php
109 ./wp-admin/network/user-new.php
100 ./wp-admin/link-manager.php
410 ./wp-admin/widgets.php
108 ./wp-content/plugins/akismet/widget.php
104 ./wp-content/plugins/google-analytics-for-wordpress/wp-gdata/wp-gdata.php
104 ./wp-content/plugins/cyr2lat-slugs/cyr2lat-slugs.php
,,,,
652239 total

As you see the cmd counts and displays the number of source code lines encountered in each and every file, for big directory structures the screen gets floated and passing | less is nice, e.g.:

find . -name '*.php' | xargs wc -l | less

Displaying lines of code for each file within the directories is sometimes unnecessery, whether just a total number of programming source code line is required, hence for scripting purposes it is useful to only get the source lines total num:::

server:/var/www/wp-website1# find . -name '*.php' | xargs wc -l | grep -i '\stotal$'

Another shorter and less CPU intensive one-liner to calculate the lines of codes is:::

server:/var/www/wp-website1# ( find ./ -name '*.php' -print0 | xargs -0 cat ) | wc -l

Here is one other shell script which displays all file names within a directory with the respective calculated lines of code

For more professional and bigger projects using pure Linux bash and command line scripting might not be the best approach. For counting huge number of programming source code and displaying various statistics concerning it, there are two other tools – SLOCCount
as well as clock (count lines of code)

Both tools, are written in Perl, so for IT managers concerned for speed of calculating projects source (if too frequent source audit is necessery) this tools might be a bit sluggish. However for most projects they should be of a great add on value, actually SLOCCount was already used for calculating the development costs of GNU / Linux and other projects of high importance for Free Software community and therefore it is proven it works well with ENORMOUS software source line code calculations written in programming languages of heterogenous origin.

sloccount and cloc packages are available in default Debian and Ubuntu Linux repositories, so if you're a Debilian user like me you're in luck:::

server:~# apt-cache search cloc$
cloc - statistics utility to count lines of code
server:~# apt-cache search sloccount$
sloccount - programs for counting physical source lines of code (SLOC)

Well that's all folks, Cheers en happy counting 😉

How to convert file content encoded in windows-cp1251 charset to UTF-8 (with iconv) to be delivered properly encoded to browsing end clients

Wednesday, May 16th, 2012

windows-cp1251 bulgarian to UTF-8 / Encoding Communication Decoding Communication Funny Picture

I have a bunch of old html files all encoded in the historically obsolete Windows-cp1251. Windows-CP1251 used to be common used 7 years ago and therefore still big portions of the web content in Bulgarian / Russian Cyrillic is still transferred to the end users in this encoding.

This was just before the "UTF-8 revolution", where massively people started using UTF-8,
Well it was clear the specific national country text encoding standards will quickly be moved by to UTF-8 – Universal Encoding format which abbreviation stands for (Unicode Transformation Format).

Though UTF-8 was clear to be "the future", many web developers mostly because of their incompetency or using an old sources of learning how to writen in HTML continued to use windows-cp1251 in HTMLs. I'm even convinced, there are still developers out there who are writting websites for Bulgarian / Russian / Macedonian customers using obsolete encodings …

The smarter developers of those accustomed to windows-cp1251, KOI-8R etc. etc., were using the meta tag to specify the type of charset of the web page content with:

<meta http-equiv="content-type" content="text/html;charset=windows-cp1251">

or

<meta http-equiv="content-type" content="text/html;charset=koi-8r">

Anyhow, still many devs even didn't placed the windows-cp1251 in the head of the HTML …

The result for the system administrator is always a mess – a lot of webpages that are showing like unreadable signs and tons of unhappy customers.
As always the system administrator is considered responsible, for the programmer mistakes :). So instead of programmers fix their bad cooking, the admin has to fix it all!

One quick work around me as admin has applied to failing to display pages in Cyrillic using the Windows-cp1251 character encoding was to force windows-cp1251 as a default encoding for the whole virtualhost or Apache directory with Apache directives like:

<VirtualHost *:80>
ServerAdmin some_user@some_host.com
DocumentRoot /var/www/html
AddDefaultCharset windows-cp1251
ServerName the_host_name.com
ServerAlias www.the_host_name.com
....
....
<Directory>
AddDefaultCharset windows-cp1251
>/Directory>
</VirtualHost>

Though this mostly would, work there are some occasions, where only a particular html files from all the content served by Apache is encoded in windows-cp1251, if most of the content is already written in UTF-8, this could be a big issues as you cannot just change the UTF-8 globally to windows-cp1251, just because few pages are written in archaic encoding….
Since most of the content is displayed to the client by Apache (as prior explained) just fine, only particular htmls lets's ay single.html, single2.html etc. etc. are displayed with some question marks or some non-human readable "hieroglyphs".

Below is a screenshot from two pages returned to my browser in wrongly set htmls charset:

Improper Windows CP1251 encoding with Apache set to serve UTF-8 encoding questiomarks

Improper Windows CP1251 delivered page in UTF-8 browser view

Apache returns cp1251 in some non-UTF8 wrong encoding (webserver improperly served cyrillic encoding)

Improperly served encoding CP1251 delivered by Apache in non-utf-8 encoding

When this kind of issues occur, the only solution is to simply login to the server and use iconv command to convert all files returning unreadable content from whatever the non UTF-8 encoding is lets say in my case Bulgarian typeset of cp1251 to UTF-8

Here is how the iconv command to convert between windows-cp1251 to utf-8 the two sample files named single1.html and single2.html

server:/web# /usr/bin/iconv -f WINDOWS-1251 -t UTF-8 single1.html > single1.html.utf8
server:/web# mv single1.html single1.html.bak;
server:/web# mv single1.html.utf8 single1.html
server:/web# /usr/bin/iconv -f WINDOWS-1251 -t UTF-8 single2.html > single2.html.utf8
server:/web# mv single2.html single2.html.bak;
server:/web# mv single2.html.utf8 single2.html

I always, make copies of the original cp1251 encoded files (as you see mv single1.html single1.html.bak), because if something goes wrong with convertion I can easily revert back.

If there are 10 files with consequential numbers naming they can be converted using a short for loop, like so:

server:/web# for i $(seq 1 10); do
/usr/bin/iconv -f WINDOWS-1251 -t UTF-8 single$i.html > single$i.html.utf8;mv single$i.html single$i.html.bak
mv single$i.html.utf8 single$i.html
done

Just as earlier mentioned if single1.html, single2.html … has in the html <head>:

<meta http-equiv="Content-Type" content="text/html; charset=windows-1251">

You should open, each of the files in question and wipe out the line either by hand or use sed to wipe it in one loop if it has to be done for lets say 10 files named (single{1..10})

server:/web# for i in $(seq 1 10); do
sed '/<meta http-equiv="Content-Type" content="text\/html; charset=windows-1251>/d' single$i.txt > single$i.txt.new;
mv single$i.txt single$i.txt.bak;
mv single$i.txt.new single$i.txt

Well now,

How to upgrade single package with their dependencies on Debian and Ubuntu Linux

Friday, March 16th, 2012

Debian GNU / Linux apt-get upgrade a package selection of a whole bunch of packages ready to upgrade apt artistic logo

Are you a Debian System Administrator and you recently run apt-get upgrade && apt-get upgrade finding out there are plenty of new packagesfor upgrade? Do you need only a pre-selected number of packages to upgrade with apt?
I run apt-get update && apt-get upgrade on one of our company Debian servers, just to see there are a number of packages to be upgraded among which there was some I didn't wanted to upgrade. Here is a little paste output from apt-get upgrade:

debian:~# apt-get update && apt-get upgrade
Hit http://security.debian.org squeeze/updates Release.gpg
...
Hit http://security.debian.org squeeze/updates/main amd64 Packages
Fetched 128 kB in 0s (441 kB/s)
Reading package lists... Done
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
at imagemagick libdbd-pg-perl libfreetype6 libmagickcore3 libmagickcore3-extra libmagickwand3 libmysqlclient16 mysql-client
mysql-client-5.1 mysql-common mysql-server mysql-server-5.1 mysql-server-core-5.1
Do you want to continue [Y/n]
14 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

From first sight it seems logical to issue apt-get upgrade packagename to upgrade only single package with its package dependencies, instead of the whole group the above packs. However doing:
apt-get upgrade imagemagick will still try to upgrade all the packages instead of just imagemagick and its dependency package deb libmagickcore3

debian:~# apt-get upgrade imagemagick
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be upgraded:
at imagemagick libdbd-pg-perl libfreetype6 libmagickcore3 libmagickcore3-extra libmagickwand3 libmysqlclient16 mysql-client
mysql-client-5.1 mysql-common mysql-server mysql-server-5.1 mysql-server-core-5.1
14 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Do you want to continue [Y/n]

Doing all package,upgrade is not a good idea in my case, since upgrading mysql-server will require a MySQL server restart (something which we cannot afford to do right now) on this production server.
MySQL server restart during upgrade is never a good idea especially on productive busy (heavy loaded) SQL servers.
A restart of the MySQL server serving thousands of requests per second could lead often to crashed tables and hence temporary server downtime etc.

Still it is a good idea to upgrade the rest of packages with their newer versions. For exmpl. to upgrade; imagemagick, at , libfreetype6 and so on.

In order to upgrade only this 3 ones and their respective package dependencies, issue:

debian:~# apt-get --yes install imagemagick at libfreetype6

Repeat the apt-get install command with passing all the single package name you want to be upgraded and voila you're done :).
Be sure the apt-get install packagename upgrade doesn't require also upgrade of myssql-server, mysql-client, mysql-common or mysql-server-core-5.1 or any of the package name you want to preserve from upgrading.