(Video: Watch this video on the post page)

Some sources and resources

Maintenance for prevention of hard drive problems

• Disk Maintenance under Linux (Disk Recovery), January 1st, 1997 by David A. Bandel, “The ins and outs of disk maintenance—what we all should know and DO.”

Repairing a broken linux distro, filesystem, bootloader

Most distros – Fedora, Mandriva, SUSE, Ubuntu, etc. – come with a “fix” or repair option similar to the F8 options available when booting MS Windows. This provides a minimalist environment from which you can test a drive and run automated repairs (eg with fsck). However it’s best if you “touch” a broken drive as little as possible to avoid damaging data further and so using a boot-from-CD (or more commonly now DVD) tool is often best.

• Tomsrtbt
• Knoppix, eg see this review of recovery options with Knoppix.
• UBCD, Ultimate Boot CD

In addition to these options often a drive manufacturer – Western Digital, Seagate, Maxtor, Hitachi, etc. – will have a tool to diagnose issues and possibly even perform some automated fixes.

• [industry tools]

Finally there are tools to recover partitions, MFT, rebuild boot sectors, copy back or undelete eleted files.

• TestDisk is a powerful free data recovery software. It helps recover lost partitions making non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses or human error (such as accidentally deleting a Partition Table). Partition table recovery using TestDisk is really easy. and/or

Recovery of lost files, damaged partitions, broken RAIDS

• Spinrite from Gibson Research: SpinRite v6.0 recognizes and operates on ALL file systems. It can even be used to repair and recover Apple Macintosh and Tivo hard drives by temporarily moving them into an Intel-based PC. It can also be used to check the health of drives that have not yet been formatted.
  
  SpinRite v6.0 brings along and automatically boots a copy of the FreeDOS operating system, so it will run even if you have no “DOS”. It can create bootable diskettes, CD?R’s, USB Flash drives and other media.
• Photorec despite the name is an application to recover any type of data file not just photos and pictures.

OEM supplied hard disk drive repair tools

All links tested March 2009.

• Maxtor/Quantum http://www.maxtor.com/en/main/support.html
  • At the tertiary level Maxtor’s site simply redirects to the relevant part of Seagate’s website. Seagate acquired Maxtor in 1996 but still uses the Maxtor brand on some equipment.
• Fujitsu http://www.fujitsu.com/us/services/computing/storage/hdd/support/
  • Diagnostic Tools
  • UDMA Utilities
  • Flash Utility
  • Change Definition Utility
  • Erase Utility
  • Ontrack Disk Manager®
• Samsung http://www.samsung.com/uk/support/download/supportDownMain.do
  • No direct links available, choose product from the Samsung onsite support wizard.
• Seagate http://www.seagate.com/www/en-us/support/downloads/seatools/
  • Download SeaTools for DOS
  • Download SeaTools for Windows
  • Legacy: Windows Version Linux Command Line Version
• Western Digital http://support.wdc.com/product/download.asp?lang=en; www.westerndigital.com
  • Data Lifeguard Tools 11.2 for Windows
  • Data Lifeguard Tools 11.2 for DOS (CD)
  • Data Lifeguard Tools 11.2 for DOS (Floppy)
  • Data Lifeguard Diagnostic for DOS (Floppy)
  • Data Lifeguard Diagnostic for DOS (CD)
  • Data Lifeguard Diagnostic for Windows
  • IDE RAID Compatibility Upgrade – 3Ware Cards
  • IDE RAID Compatibility Upgrade – Non-3Ware Cards
  • Old Data Lifeguard Diagnostic
  • Data Lifeguard Tools 11.0 for DOS
  • Data Lifeguard Tools 11.0 for DOS (CD)
• IBM and Hitachi http://www.hgst.com/hdd/support/download.htm#DFT
  • Install or Optimize Your Drive – Utilities for installing or optimizing Hitachi HDDs
    • Feature Tool – Change various ATA features.
    • Power Booster – Control advanced battery life extender power settings.
    • Disk Manager
  • Analyze, Monitor and Restore Your Drive – Utilities for analyzing, monitoring and restoring Hitachi HDDs
    • Drive Fitness Test
    • Feature Tool
    • OGT Diagnostic Tool
    • SMART Defender

  Other techniques

  Dangerous hard drive recovery tricks

  • Drop it to release a stuck platten.
  • Freeze it (in an airtight bag) to release stuck parts.

Currently supported services are:

Download @ http://wordrider.net/freerapid/download.html

*Hiren’s BootCD 10.6

Hiren’s BootCD (HBCD) is a completely free bootable CD that contains a load of useful tools you can make use of in a variety of situations like analyzing, recovering and fixing your computer even if the primary operating system can not be booted.

It is a great resource for anyone with computer problems who is having trouble accessing the internet to download programs in an attempt to fix it. It has a multitude of tools divided into a number of categories like partitioning tools, backup, recovery and BIOS/CMOS tools to name a few.

With some simple knowledge about what is contained on the CD, you can use it to repair many problems computer like hard drive failure, virus infections, partitioning, password recovery and data recovery.

We may call it as an emergency cd which every computer technician or home user must have.

Partition Tools

If you need to make changes to the partitions on your computer, there are several applications that provides various levels of functionality for accomplishing this goal. You can both create and delete partitions from your computer, even while there are other partitions on the hard drive you are modifying. You can also resize partitions if needed, to change how much space is allocated to them.

Backup and Recovery

There are several backup and recovery tools on Hiren’s BootCD. Backup tools like GetDataBack, HDD Scan, Partition Find and Mount, PhotoRec, Recuva, Undelete… let you copy data off of your hard drive and schedule automatic backups to ensure your data is saved to another location. You can also recover deleted data, whether that data was deleted intentionally or accidentally. There are also a few tools that will help you recover data from damaged or corrupted portions of your hard drive if you are unable to recover them through other methods.

Testing Tools

Hiren’s BootCD provides a variety of tools for testing different aspects of your computer. If you suspect that your RAM is corrupted or that a piece of hardware on your machine is not functioning properly, there are several applications you can run to determine the problems. You can also perform hard drive tests to see whether your hard drive is physically damaged, and get a report on how much longer your hard drive is expected to work.

Password Tools

Password recovery and modification tools are also provided on Hiren’s BootCD. You can change the administrator password on Windows machines, and there are utilities for saving passwords for your online accounts in an encrypted format. You can also encrypt your entire hard drive with Hiren’s BootCD so that a password is required to read or write any data from or to your hard drive.

Updated softwares:

New added softwares:

+ Update Checker 1.037: Scans your computer for installed software and checks for newer releases on FileHippo.
+ Speccy 1.02.156: An advanced System Information tool for your PC.
+ BootICE 0.78: Boot sector manipulation utility.
+ MyUninstaller 1.65: Alternative to the standard add / remove control panel module.
+ SearchMyFiles 1.47: Alternative to ‘Search For Files And Folders’ module of Windows + Duplicates Search.
+ Glary Registry Repair 3.3.0.852: An advanced registry cleaner that allows you to safely scan, clean, and repair registry problems.
+ HDHacker 1.4: Load/Save/View MBR and BootSector from a physical/logical drive.
+ Delete Doctor 2.2: Delete Files that are hard to delete, Option to delete on reboot or via UNC Name.
+ Write Protect USB Devices: Tweak your PC to make USB Pen Drive, Memory Card or Thumb Drive as Read Only.
+ Protect a Drive from Autorun Virus: Protect your pen drive from being infected when you plug it in an infected PC.
+ SumatraPDF 1.1: A free, open source, lightweight PDF Reader for Microsoft Windows.
+ RegShot 1.8.2: A registry compare utility that allows you to quickly take a snapshot of your registry and then compare it with a second one: done after doing system changes or installing a new software product.
+ KeyTweak 2.3.0: A program to Remap Keyboard Layout, you can even customize a broken key to an unused key.
+ Bart’s Stuff Test 5.1.4: Long term heavy stress testing storage devices.

*Ultimate Boot CD 5.0.2

You need the Ultimate Boot CD if you want to:

• Run floppy-based diagnostic tools from CDROM drives. More and more PCs are shipped without floppy drives these days, and it is such a royal pain when you need to run diagnostic tools on them.
• Free yourself from the slow loading speed of the floppy drive. Even if you do have a floppy drive, it is still much much faster to run your diagnostic tools from the CDROM drive, rather than wait for the tool to load from the floppy drive.
• Consolidate as many diagnostic tools as possible into one bootable CD. Wouldn’t you like to avoid digging into the dusty box to look for the right floppy disk, but simply run them all from a single CD? Then the Ultimate Boot CD is for you!
• Run Ultimate Boot CD from your USB memory stick. A script on the CD prepares your USB memory stick so that it can be used on newer machines that supports booting from USB devices. You can access the same tools as you would from the CD version.

New features in UBCD V5.0 include:

• New! The Linux-based distro Parted Magic is now included with UBCD V5.0. This should be the method of choice when you need to resize/rescue partitions, access NTFS filesystems or work with USB storage devices.
• New! UBCD V5.0 now supports both syslinux/isolinux and grub4dos. This helps improve the chances that UBCD will boot on any particular machine.

When you boot up from the CD, a text-based menu will be displayed, and you will be able to select the tool you want to run. The selected tool actually boots off a virtual floppy disk created in memory.

===================================================

This torrent includes the Hiren’s BootCD version 10.6 and The Ultimate Boot CD version 5.02 with tools needed to boot from USB Drives.

To use Hiren’s on a USB drive, use these instructions: http://www.hirensbootcd.net/usb-booting.html

To use the Ultimate Boot CD, change the iso name to ubcd501.iso and use the included USB installer (The reason you have to do this is that pendrivelinux.com hasn’t released a version of their easy USB install program that support the ubcd502.iso yet).

Otherwise, burn to CD with your favorite ISO program and enjoy these highly useful tools!

Click here to download the torrent or Click to get help download torrent

ps -f
UID PID PPID STIME TTY TIME COMD
hermie 24 1 00:35:28 tty1 0:01 bash
hermie 137 24 00:36:39 tty1 0:00 ps -f

The output here shows, for each active task, the UID (owning user), PID (process ID), PPID (parent process ID), STIME (when the task started), TIME (how long the task has been active), and CMD (the actual command line used to start the task). If you exa mine the PIDs and PPIDs, you can see that bash invoked the ps -f command, because the PPID of the latter matches the PID of the former.

Launching Tasks in the Foreground and Background

Suppose you have a long-running task (for example, compiling a large program) that you need to run, but you also want to get some other work done. Linux lets you start a task in the background and keep on doing other things from the command prompt. By a dding the ampersand (&) to the end of any command, you can launch it in the background and get your command prompt back right away. For example,

cc hugepgm.c > outlist &

will start cc (the C compiler) as a background task, executing it in parallel with other tasks on your system.

Note: It’s a good idea to redirect the output of background tasks to a file, as shown here, since the background task still shares the console with foreground tasks. If you don’t, the background task will splash any output it might produce all over your screen while you’re editing a file or typing another command.

If you start a long-running task and forget to add the ampersand, you can still swap that task into the background. Instead of pressing ctrl-C (to terminate the foreground task) and then restarting it in the background, just press ctrl-Z after the command starts, type bg, and press enter. You’ll get your prompt back and be able to continue with other work. Use the fg command to bring a background task to the foreground.

You might wonder why you’d ever want to swap programs between the foreground and background, but this is quite useful if for example you’re doing a long-running compile and you need to issue a quick command at the shell prompt. While the compilation is running, you could press ctrl-Z and then enter the bg command to put the compiler in the background. Then do your thing at the shell prompt and enter the fg command to return the compiler task to the foreground. The ctrl-Z trick also works with the Emacs text editor and the Pine email program. You can suspend either program and then return t o your work in progress with the fg command.

Of course, in the X Windows environment, all these unnatural gyrations are not necessary. Just start another shell window and run the other command there. You can watch both processes running in separate windows at the same time, and you don’t have to w orry about adding ampersands, piping output to files, or keeping track of foreground versus background processes.

Table of Contents

• Starting vi
• Cursor keys
• Word and Line Movement keys
• Number counts
• Cancelling commands
• Status line
• Scroll commands
• Delete commands
• Input/editing commands
• Search
• Copy, paste, undo, repeat
• Ex commands (file commands)
• Search and replace

vi Editor (visual display editor)

Unlike most word processors you may be used to, vi does not use modifier keys in command sequences. Typically on a PC, you would use some combination of function keys, alt, shift and ctrl. Vi was written to run on a text based system, and so almost entirely uses no modifier keys for commands.

Vi has two operational modes: COMMAND mode and INPUT mode.

When you start vi, you are in COMMAND mode. When you add, insert, replace, or change text, you need to enter INPUT mode. Pressing the ESC (Escape) key at any time, will return you to the command mode. If you are already in command mode, your terminal will simply beep you, telling you so.

For the next several sections, we will be in command mode only. We will learn about the input mode once we know how to navigate around in a file.

Starting vi

To invoke vi with a new (blank) file, simply type “vi” at the prompt:

>> prompt% vi

You should get a screen with the cursor blinking at the top left, and tildes “~” along the left margin. The tildes indicate that those lines are completely void of any characters (spaces, tabs, returns included).

To edit an existing file, type “vi” followed by the filename:

>> prompt% vi filename

You should see your file, along with a status line along the bottom stating the name of the file, the number of lines, and the number of characters in that file:

Example: "pton.list" 399 lines, 22543 characters

To view a file only (you will not be making any changes, or want to prevent any accidental changes) type “view” followed by the filename:

>> prompt% view filename

Cursor Keys

You can move the cursor around using the movement keys. “h” and “l” moves the cursor left and right; “j” and “k” moves down and up.

                                  (up)    

                                   k
                   (left)     h         l    (right)
                                   j       

                                 (down)

NOTE: The arrow keys work in vi as well, but not all terminals may have them. In any case using hjkl is recommended, since it keeps your hands on the keyboard, and so you don’t have to reposition your hand everytime you move the cursor. Alternative keys:

                                  (up)    

                                   -
             (left)  Backspace            (spacebar) (right)
                                   +       

                                 (down)

Word and Line Movement Keys

If you’re editing a file that’s primarily text (that is, words and sentences and not a ton of computer code) there are more convenient ways to move around than one column/row at a time.

We’re still in command mode. To move to the beginning of the next word, type “w”. To move to the beginning of the previous word, type “b”. You can also move to the end of the next word, type “e”.

>> Beginning of next word      w
>> Beginning of prev word      b

You can also jump to the start and end of lines if you’re somewhere in the middle. 0 (zero) or ^ (caret) jumps to the start, “$” jumps to the end.

>> Start of line               0 (zero) or ^
>> End of line                 $

If you’re a fan of run-on sentences, you might want to jump from sentence to sentence. Use “(” to move to the start of the previous sentence and “)” to move to the start of the next sentence.

>> Start of previous sentence   (
>> Start of next sentence       )

We can jump in even larger units. Using “{” and “}”, we can jump to previous and next paragraphs.

>> Start of previous paragraph  {
>> Start of next paragraph      }

Also, if you hit RETURN at any time, you will move to the beginning of the *next* line down.

>> Start of following line:  RETURN

There are also several commands to jump to relative locations on the screen and in the file:

>> Move to top of screen         H (home)
>> Move to middle of screen      M (middle)
>> Move to last line of screen   L (last)

One other useful command, is “G”, which let’s you jump to the end of your file:

>> Last line in file             G

In the next section we’ll see how to jump to any line in a file.

Number Counts

Much of the time even using the word movement keys is too slow. If we could jump any number of words/lines instead of having to press the keys each time, things would be much easier. Vi, therefore, provides a way to repeat commands.

>> To repeat command X, n times:  nX

Examples:

To move 10 lines down         10j
To move 4 characters left     4h
To move 5 words right         5w

Number counts can be used with almost all movement and editing commands. As you know, “G” by itself moves to the last line. To move to the first line of a file, type “1G”. To move to the nth line, type “nG”.

>> First line in file:  1G

Example: 45th line in file 45G

Cancelling Commands

If at any time, you want to cancel a number count or any other command before you finish typing it, you can always hit ESCAPE.

Status Line

Sometimes when you jump around in a file a lot, you lose track of where you are. CTRL-G will give your current position and the file name you’re editing at the bottom of the screen. It should look something like:

"filename" line 20 of 399 --5%--

Scroll Commands

When you’re simply reading through a file, often times you just want to page through the text and not make any changes. Having to type “40j” every page would be too tedious.

Fortunately, vi has a set of scroll commands. To scroll down a screen (forward), press CTRL-f. To scroll back a screen (backwards), press CTRL- b. To scroll up half a screen, CTRL-u. To scroll down half a screen, CTRL-d.

>> Scroll forward one screen    CTRL-f
>> Scroll back one screen       CTRL-b        

>> Scroll up half a screen      CTRL-u
>> Scroll down half a screen    CTRL-d

Delete Commands

To delete a single character, type “x”. This deletes the character directly under the cursor and moves the remaining text to the right one space to the left.

>> To delete a single character at cursor      x

We can combine number counts with “x” as well:

Example:
delete 4 characters: 4x

Of course, if you want to delete large sections of text, typing “9999x” is a bit unwieldy. Fortunately (as you may have guessed), vi has another delete command, “d”.

By now, you know how to move an distance in any direction by combining a number with a movement key. The delete commands work in a similar fashion.

“d” is always used with another command, never by itself. We need to tell it which direction you want to delete and how far in that direction. We already know how to move any distance in any direction, right? Now all we do is combine “d” with any movement key and we’ve learned almost all the delete commands.

>> To delete from cursor to start of next word         dw
>> To delete from cursor to end of line                d$
>> To delete from current line to bottom of screen     dL
>> To delete one character before cursor               dh

(Note: “dl” works to delete one character at the cursor, but this is exactly what “x” does.)

Vi does provide a short cut for d$. You can use “D” to the same effect.

>> Shortcut delete from cursor to end of line     D

To delete the current line, instead of having to type “^d$” (move to start of line and delete to the end), vi has a shortcut command, “dd”.

>> To delete the current line   dd

Of course, “d” is just like any other command, so we can combine a number count with any “d” command.

Examples: Delete three words: 3dw Delete three words: d3w

Two ways? Which one is right? Vi isn’t picky. They’re both right. Deleting three words once (d3w) is the same as delete one word three times (3dw).

Now…what command would you use to delete 5 lines starting from the current line?

The expected way: 5dd Alternate way: 4dj

Why “4dj”? Remember, deletion always occurs relative to the cursor position when we give it a direction. So “4dj” deletes the current line and the 4 lines below it. Similarly, “4dk” deletes 5 lines, the current line and the 4 lines above it.

Other delete commands:

>> Delete from current line to end of file     dG
>> Delete from current line to start of file   d1G
>> Delete line 5                               5Gdd
    (this is merely combining two commands, 5G and dd)

Input/Editing Commands (finally!)

Now that we know how to navigate through files and delete text from them it’s time we learn how to insert text. There are six input modes: append, insert, change, open, substitute, and replace. Each mode has two invocations, lowercase first letter and uppercase first letter (i.e., “a” and “A” for append).

Remember that we always start in command mode. As soon as you type any of the input commands (except “r” replace) you stay in input mode until you hit ESCAPE. So in order for you to go back any make changes in what you’ve typed, just press ESC and move to where you have to go and enter the appropriate input mode.

To enter text, use either insert (i or I) or append (a or A).

>> Insert text before the cursor    i
>> Insert text after the cursor     a

>> Insert text at start of line     I
>> Insert text at end of line       A

Number counts, of course, can be used to do repeated insertions of text.

>> Insert 5 "newtext"       5inewtext 

Example:  insert 5 copies of "hello"      5ihello

If you need to insert blank lines, use open (o or O).

>> Insert blank line below current line     o
>> Insert blank line above current line     O

(Just think of “lowercase = lower/below” and “uppercase = uppper/above”.)

Often times you want to type over something instead of having to insert new text and then delete old text. To do this we use change.

>> Change from cursor to end of line     C
>> Change a word to "newtext"            cwnewtext
>> Change entire line                    cc  (vi will blank out the entire
                                              line)

Note that when you use “C” vi will change the last character in the line to “$” to show you what how far your change in the text will delete the old text.

Similarly for “cw”, vi will change the last character of the word you intend to change into “$”.

Replace and substitute are fairly similar to change, although with subtle differences in usage.

>> Replace character at cursor with x        rx
>> Replace (overwrite) from cursor onward    R

Examples replace with 5 "g"'s             5rg

Note that “r” with or without a number count will replace and then return you to command mode. “R” stays in input mode.

>> Substitute one or more characters for a single character    snewtext
>> Substitute entire line                                      S

Search (see also Search and Replace later in this section)

To jump a string or substring anywhere in your file, type “/” and the string you want to search for.

>> Search for a string "foo"     /foo

This search will move your cursor to the next occurrence (forwards search) of “foo” if it exists. You can jump to the next occurrence either by typing “/” by itself, or “n”. If you want to search backwards, use “N”.

>> Repeat search forward     n or /
>> Repeat search backward    N

If you are at the last occurrence of a string, a repeat search forward (n or /) will start search again from the top of the file. If the pattern doesn’t exist, it will give you the message “Pattern not found”.

Copy, Paste, Undo, Repeat

Vi also has the capacity to copy and paste text. Copying text is much like deleting text. You give it the copy command and then a direction and distance in that direction. The copy command is “y” (yank).

>> Copy current line     yy  or Y
>> Copy a word           yw
>> Copy 4 words          y4w  or 4yw

Now to paste what you’ve just copied, use the paste command, “p”, to paste after the cursor, “P” to paste before the cursor.

>> Paste after cursor    p
>> Paste before cursor   P

What about cut n’ pasting? You, in fact, already know how to cut and paste. The delete commands automatically save the text you last deleted into the paste buffer. It’s important to note that using the “x” command only deletes one character at a time, and therefore vi only saves each character individually. If you type “x” repeatedly and try to paste, you will only paste one letter.

However, if you use a number count with x, like “25x”, paste *will* insert all 25 characters.

>> Reversing two lines      ddp
>> Reverse two characters   xp

To paste what you previously pasted again, but somewhere else, go to your next point of insertion, and type Ctrl-@.

>> Insert previously pasted text here        ^@ (max of 128 chars)

You can also paste text without having to move your cursor to the location you want to paste to.

>> Paste current line after line 5  :t 5
>> Paste line x after line 5         t 5
>> Paste line 9 after line 5        :9t 5

If you want to move the text, instead of just pasting, use :m.

>> Move current line after line 5   :m 5
>> Move line x after line 5          t 5
>> Move line 9 after line 5         :9t 5

Of course, all this cutting and pasting would be rather dangerous if we couldn’t reverse the changes if we don’t like it. So of course vi has an undo command, and as you’d expect, it’s the letter “u”. Undo comes in two forms, like all the other commands: lowercase and uppercase.

>> Undo last modification                u
>> Undo all changes on a given line      U

“U” will undo all changes on a given line *only* if you keep the cursor on that line. As soon as you move the cursor to another line, you cannot undo all changes on that line. You can still undo the last change however using “u”. If you want to repeat the last editing command you did, use “.”

ex Commands (saving files, opening files, quiting vi)

Before vi was written, the only way to edit files was to use the line editor, ex. You had could only process one line at a time. Nowadays, there’s no need to rough it anymore, but vi carries over some of the file saving, opening, and quitting commands.

The ex commands are all invoked with the colon, “:”. Once you type “:”, vi will give you the ex prompt “:” in the lower left corner.

Saving and Quiting
Once you finish your editing, you’ll want to save your work and exit vi. There happen to three ways to quit and save.

>> To write (save) to file and quit  -->   :wq
                                            
                                            ZZ   (no colon)

Saving only
Often times you’ll want to save your work while still working on it (in case you accidentally get logged out, or the machine crashes, or you somehow lose your changes). To do this, simply type “:w”.

>> To write (save) to file     -->   :w
>> To write (save) to newfile  -->   :w filename

Vi protects your files, so in case you try to write to a file that exists, it will give you a message: “foo” File exists – use “w! foo” to overwrite

If you want to overwrite the existing file, then you use :w! filename

>> To write over existing file  -->  :w! filename

Quiting only
If you haven’t made any changes and simply want to exit, just type “:q”. If you *have* made changes, but do NOT want to save them, and you want to exit, then type “:q!”.

>> To quit                       --> :q
>> To quit (don't save changes)  --> :q!

Shell escapes
If you need to execute a UNIX command while in vi you can make use of the shell escape. Just type “:! command”. Vi will execute your command and then return to your editing after you hit RETURN.

>> Execute UNIX command  -->   :! command

Shell escapes are useful for checking on filenames in your directory, or maybe reading mail that has recently come in.

Example,  :! ls

(see UNIX help section on alternate ways to do this, re: suspending jobs)

Opening files
Often times you’ll be editing a series of files. Having to type “vi file1″ and exiting with :wq each time can be a hassle. If you know the name of your other files, you can open those files from inside vi, by typing “:e file2″.

>> Open another file  -->  :e filename

If you have made changes to your current file, you need to save your changes before using “:e” to open another file. However, as with :w and :q, you can override this by using “:e!”

>> Open another file (don't save most recent changes)  -->  :e! filename

Inserting files
If you write a lot of mail message or post a lot of articles to USENET, many times you’ll want to append or insert other documents into your letter or article. To do this, move your cursor where you want the file, and type “:r filename”

>> Insert file at cursor position -->  :r filename

Status line
We saw back in the status line section that CTRL-g gives your file’s attributes. An alternative way is to use “:f”. This command also informs you if the file has been changed since you opened it with vi.

>> Show file status  -->   :f

Search and Replace

This is about as complicated as it gets in vi, since search and replace sytnax is taken from the UNIX sed (stream editor) command.

>> Global search and replace  -->  :1,$ s/old/new/g
                                     ^  ^  ^   ^  ^
In english, this means:              |  |  |   |  |
                                     |  |  |   |  |
            From 1 to $ (end of file)   |  |   |  |
                                        |  |   |  |
            substitute -----------------/  |   |  |
                                           |   |  |
            occurrences of "old" ----------/   |  |
                                               |  |
            with occurrences of "new" --------/   |
                                                  |
            globally (i.e., all instances of "old")

I won’t go into details on using sed in this section (see the UNIX sections on sed and regular expressions), but you can easily change the range to search and replace from by changing “1″ and “$” to your needs.

March 17, 2010 | 4:29 pm
There are certainly many genetic mutations that increase a woman’s risk of developing breast cancer. The most famous examples are variations in the genes BRCA1 and BRCA2 (whose names are short for BReast CAncer).

More common are the single-letter DNA changes called single nucleotide polymorphisms– or SNPs for short. Researchers have identified many SNPs that appear to be associated with breast cancer because they are more common in women who have the disease.

But can those SNPs be used to predict an individual woman’s risk of developing breast cancer? That was the question that a large group of researchers from the National Cancer Institute, the American Cancer Society and a host of other esteemed institutions set out to answer.

The group tested 10 SNPs that have “established associations with breast cancer,” they write in Thursday’s issue of the New England Journal of Medicine. Using data on 5,590 women with breast cancer and 5,998 healthy controls, they found that those SNPs alone did just as good a job of predicting a woman’s breast cancer risk as the government’s Breast Cancer Risk Assessment Tool, which relies on family health history, age at the time of first menstrual period and other personal information. Combining the SNPs and the traditional risk model boosted their predictive accuracy only slightly, the researchers found.

They also looked at how the addition of the SNP data changed the risk prediction for the women in the study. In 26% of cases, it moved women into a higher risk category, and in 28% of cases it moved women to a lower risk category. In the remaining 46% of cases, there was no change.

All in all, the researchers said the use of SNPs to predict breast cancer risk still isn’t ready for prime time. “Our results indicate that the recent identification of common genetic variants does not herald the arrival of personalized prevention of breast cancer in most women,” they wrote.

Perhaps researchers are getting a little more realistic about the predictive value of SNPs. A study published last month in the Journal of the American Medical Assn. found that nearly 100 SNPs linked to heart disease did almost nothing to predict the risk of heart attacks, strokes, coronary artery disease or cardiovascular death.

However, in an editorial accompanying the study, a pair of European scientists who focus on breast cancer genetics said the problem isn’t that the SNPs don’t work – it’s that we haven’t identified enough of them.

The 10 SNPs examined in the study “are no more than the tip of the iceberg,” they wrote. “A more pressing question is why … only a dozen risk alleles have been identified.”

– Karen Kaplan

If the two predictive methods are roughly equally accurate (with accuracies substantially greater than chance, or else they would have no predictive value at all), BUT combining the two methods does not result in any increase in overall accuracy, the implication is that they somehow must overlap. Which would be a very interesting result. Because while one of the methods is purely physiological (DNA mutations), the other is purely clinical (personal & family development, as measured by the Risk Assessment Tool). The extent to which the two methods overlap would seem to imply that the measured physiology (DNA mutations) expresses itself in the form of the listed clinical manifestations, such as age of onset of menses, etc. This would be fantastic to disentangle. A beautiful example of how a “negative” result in science can still be enormously valuable.

- my co-worker: “OK!  After much sweat, back ache and a little blood I got a working chassis, 48GB of RAM and the damn thing is booting.stay tuned for a successful ssh so I can go home.LOL”
- me: “Any luck ?”
- my co-worker: “Alright after sending that last email I went back to the server to find that the sticky that I wrote the new MAC on was gone from the PDU I stuck it to.  After searching all around I found it under a rack in the next isle.  I have now updated the config files for eth0 and eth1 and the server is rebooting.if it doesn’t come online and is able to ssh into it can I pretty please take it out back and shoot it!!! ”

Here’s an example command:

 command > /dev/null 2>&1 

Output redirection

The greater-thans (>) in commands like these redirect the program’s output somewhere. In this case, something is being redirected into /dev/null, and something is being redirected into &1.

Standard in, out, and error

There are three standard sources of input and output for a program. Standard input usually comes from the keyboard if it’s an interactive program, or from another program if it’s processing the other program’s output. The program usually prints to standard output, and sometimes prints to standard error. These three file descriptors (you can think of them as “data pipes”) are often called STDIN, STDOUT, and STDERR.

Sometimes they’re not named, they’re numbered! The built-in numberings for them are 0, 1, and 2, in that order. By default, if you don’t name or number one explicitly, you’re talking about STDOUT.

Given that context, you can see the command above is redirecting standard output into /dev/null, which is a place you can dump anything you don’t want (often called the bit-bucket), then redirecting standard error into standard output (you have to put an & in front of the destination when you do this).

The short explanation, therefore, is “all output from this command should be shoved into a black hole.” That’s one good way to make a program be really quiet!