Think about computing a Fibonacci number by recursion:

Fn = Fn-1 + Fn-2  (with F0 = 0, F1 = 1)

Lets explore the two different solutions. one without the caching and other with caching.

read more here.

1. Why was it that you left the last job that you were at?
2. What do you think your top 3 strengths are?
3. What is most important to you in a job?
4. Major difference between FAT and NTFS on a local machine?
5. How many passwords by default are remembered in an active directory?
6. What is a C name record (in DNS)?
7. What is a LM host file used for?
8. Can you name the FSMO roles in active directory?
9. What tolls would you use to gage the effect of group policy before using any tools?
10. Explain Active Directory sites and services and linked cost routing?
11. When would you use circular logging and exchange?
12. Exhange related question – as an echange admin if someone asked you how to determine if mail was delivered or not which tool would you use?
13. Can you explain how you configurated SMS.
14. Rate yourself in 3 different areas (1-5, 5 is expert)

via Sysadmin sample interview questions | TechInterviews.

via Hiring an IT guy – questions to ask | TechInterviews.

# How do you execute a UNIX command in the background?

# What UNIX command will control the default file permissions when files are created?

# Explain the read, write, and execute permissions on a UNIX directory.

# What is the difference between a soft link and a hard link?

# Give the command to display space usage on the UNIX file system.

# Explain iostat, vmstat and netstat.

# How would you change all occurrences of a value using VI?

# Give two UNIX kernel parameters that effect an Oracle install

# Briefly, how do you install Oracle software on UNIX.

via Unix admin questions | TechInterviews.

1. You need to see the last fifteen lines of the files dog, cat and horse. What command should you use?
   tail -15 dog cat horse
   The tail utility displays the end of a file. The -15 tells tail to display the last fifteen lines of each specified file.
2. Who owns the data dictionary?
   The SYS user owns the data dictionary. The SYS and SYSTEM users are created when the database is created.
3. You routinely compress old log files. You now need to examine a log from two months ago. In order to view its contents without first having to decompress it, use the _________ utility.
   zcat
   The zcat utility allows you to examine the contents of a compressed file much the same way that cat displays a file.
4. You suspect that you have two commands with the same name as the command is not producing the expected results. What command can you use to determine the location of the command being run?
   which
   The which command searches your path until it finds a command that matches the command you are looking for and displays its full path.
5. You locate a command in the /bin directory but do not know what it does. What command can you use to determine its purpose.
   whatis
   The whatis command displays a summary line from the man page for the specified command.
6. You wish to create a link to the /data directory in bob’s home directory so you issue the command ln /data /home/bob/datalink but the command fails. What option should you use in this command line to be successful.
   Use the -F option
   In order to create a link to a directory you must use the -F option.
7. When you issue the command ls -l, the first character of the resulting display represents the file’s ___________.
   type
   The first character of the permission block designates the type of file that is being displayed.
8. What utility can you use to show a dynamic listing of running processes? __________
   top
   The top utility shows a listing of all running processes that is dynamically updated.
9. Where is standard output usually directed?
   to the screen or display
   By default, your shell directs standard output to your screen or display.
10. You wish to restore the file memo.ben which was backed up in the tarfile MyBackup.tar. What command should you type?
    tar xf MyBackup.tar memo.ben
    This command uses the x switch to extract a file. Here the file memo.ben will be restored from the tarfile MyBackup.tar.
11. You need to view the contents of the tarfile called MyBackup.tar. What command would you use?
    tar tf MyBackup.tar
    The t switch tells tar to display the contents and the f modifier specifies which file to examine.
12. You want to create a compressed backup of the users’ home directories. What utility should you use?
    tar
    You can use the z modifier with tar to compress your archive at the same time as creating it.
13. What daemon is responsible for tracking events on your system?
    syslogd
    The syslogd daemon is responsible for tracking system information and saving it to specified log files.
14. You have a file called phonenos that is almost 4,000 lines long. What text filter can you use to split it into four pieces each 1,000 lines long?
    split
    The split text filter will divide files into equally sized pieces. The default length of each piece is 1,000 lines.
15. You would like to temporarily change your command line editor to be vi. What command should you type to change it?
    set -o vi
    The set command is used to assign environment variables. In this case, you are instructing your shell to assign vi as your command line editor. However, once you log off and log back in you will return to the previously defined command line editor.
16. What account is created when you install Linux?
    root
    Whenever you install Linux, only one user account is created. This is the superuser account also known as root.
17. What command should you use to check the number of files and disk space used and each user’s defined quotas?
    repquota
    The repquota command is used to get a report on the status of the quotas you have set including the amount of allocated space and amount of used space.

via Linux command line Q&A | TechInterviews.

via Linux network administrator questions | TechInterviews.

1. What is sed? – sed is stream editor, a Unix tool for working with streams of text data. See the awful truth about sed.
2. How do you substitute strings with sed? – Use ’s/old/new’ command, so sed ’s/hello/goodbye/’ would substitute the occurrence of the word hello to goodbye.
3. How do you inject text with sed? – & in the substitution string defines the pattern found in the search string. As an example, here’s us trying to find a word ‘hello’ and replacing it with ‘hello and how are you’:
   echo ‘hello there’ | sed ’s/^hello/& and how are you/’
4. Can I find several patterns and refer to them in the replacement string? – Yes, use (pattern) and then refer to your patterns as \1, \2, \3 and so on.
5. If the string is ‘old old old’ and I run ’s/old/new’, I get ‘new old old’ as the result. I need ‘new new new‘. – You forgot the global modifier, which would replace every occurrence of the pattern with the substitution. ’s/old/new/g‘ will work.
6. But I want ‘old old new’ from the previous example. – Just use the numeric modifier saying you want the third occurrence to be replaced. ’s/old/new/3‘ will work.
7. I wrote a rather complex sed script. How do I save and run it? – Assuming that your file is named myscript1.sed, you can invoke sed -f myscript1.sed.
8. How do I delete trailing whitespaces from each line? – sed ’s/[ \t]*$//’ Here we’re replacing any occurrence of a space or a tab with nothing. Check sed one-liners for more examples.
9. How do you print just a few first lines of the file? – sed 1q will give you just the first line, sed 10q the first 10 lines.
10. How do you replace a pattern only if it’s found, so that it’s executed faster? – Nest the replacement statement: sed ‘/old/ s/old/new/g’ file.txt

via Basic sed tricks | TechInterviews.

But for a given distance, Adam runs half the time, then walks another half. Bob runs half the distance, then walks another half.

If they were to compete, which distance would Adam win at, and which distances would Bob be the winner at?

Answer:

via Two men running | TechInterviews.

1. What is garbage collection? What is the process that is responsible for doing that in java? – Reclaiming the unused memory by the invalid objects. Garbage collector is responsible for this process
2. What kind of thread is the Garbage collector thread? – It is a daemon thread.
3. What is a daemon thread? – These are the threads which can run without user intervention. The JVM can exit when there are daemon thread by killing them abruptly.
4. How will you invoke any external process in Java? – Runtime.getRuntime().exec(….)
5. What is the finalize method do? – Before the invalid objects get garbage collected, the JVM give the user a chance to clean up some resources before it got garbage collected.
6. What is mutable object and immutable object? – If a object value is changeable then we can call it as Mutable object. (Ex., StringBuffer, …) If you are not allowed to change the value of an object, it is immutable object. (Ex., String, Integer, Float, …)
7. What is the basic difference between string and stringbuffer object? – String is an immutable object. StringBuffer is a mutable object.
8. What is the purpose of Void class? – The Void class is an uninstantiable placeholder class to hold a reference to the Class object representing the primitive Java type void.
9. What is reflection? – Reflection allows programmatic access to information about the fields, methods and constructors of loaded classes, and the use reflected fields, methods, and constructors to operate on their underlying counterparts on objects, within security restrictions.
10. What is the base class for Error and Exception? – Throwable
11. What is the byte range? -128 to 127
12. What is the implementation of destroy method in java.. is it native or java code? – This method is not implemented.
13. What is a package? – To group set of classes into a single unit is known as packaging. Packages provides wide namespace ability.
14. What are the approaches that you will follow for making a program very efficient? – By avoiding too much of static methods avoiding the excessive and unnecessary use of synchronized methods Selection of related classes based on the application (meaning synchronized classes for multiuser and non-synchronized classes for single user) Usage of appropriate design patterns Using cache methodologies for remote invocations Avoiding creation of variables within a loop and lot more.
15. What is a DatabaseMetaData? – Comprehensive information about the database as a whole.
16. What is Locale? – A Locale object represents a specific geographical, political, or cultural region
17. How will you load a specific locale? – Using ResourceBundle.getBundle(…);
18. What is JIT and its use? – Really, just a very fast compiler… In this incarnation, pretty much a one-pass compiler — no offline computations. So you can’t look at the whole method, rank the expressions according to which ones are re-used the most, and then generate code. In theory terms, it’s an on-line problem.
19. Is JVM a compiler or an interpreter? – Interpreter
20. When you think about optimization, what is the best way to findout the time/memory consuming process? – Using profiler
21. What is the purpose of assert keyword used in JDK1.4.x? – In order to validate certain expressions. It effectively replaces the if block and automatically throws the AssertionError on failure. This keyword should be used for the critical arguments. Meaning, without that the method does nothing.
22. How will you get the platform dependent values like line separator, path separator, etc., ? – Using Sytem.getProperty(…) (line.separator, path.separator, …)
23. What is skeleton and stub? what is the purpose of those? – Stub is a client side representation of the server, which takes care of communicating with the remote server. Skeleton is the server side representation. But that is no more in use… it is deprecated long before in JDK.
24. What is the final keyword denotes? – final keyword denotes that it is the final implementation for that method or variable or class. You can’t override that method/variable/class any more.
25. What is the significance of ListIterator? – You can iterate back and forth.
26. What is the major difference between LinkedList and ArrayList? – LinkedList are meant for sequential accessing. ArrayList are meant for random accessing.
27. What is nested class? – If all the methods of a inner class is static then it is a nested class.
28. What is inner class? – If the methods of the inner class can only be accessed via the instance of the inner class, then it is called inner class.
29. What is composition? – Holding the reference of the other class within some other class is known as composition.
30. What is aggregation? – It is a special type of composition. If you expose all the methods of a composite class and route the method call to the composite method through its reference, then it is called aggregation.
31. What are the methods in Object? – clone, equals, wait, finalize, getClass, hashCode, notify, notifyAll, toString
32. Can you instantiate the Math class? – You can’t instantiate the math class. All the methods in this class are static. And the constructor is not public.
33. What is singleton? – It is one of the design pattern. This falls in the creational pattern of the design pattern. There will be only one instance for that entire JVM. You can achieve this by having the private constructor in the class. For eg., public class Singleton { private static final Singleton s = new Singleton(); private Singleton() { } public static Singleton getInstance() { return s; } // all non static methods … }
34. What is DriverManager? – The basic service to manage set of JDBC drivers.
35. What is Class.forName() does and how it is useful? – It loads the class into the ClassLoader. It returns the Class. Using that you can get the instance ( “class-instance”.newInstance() ).
36. Inq adds a question: Expain the reason for each keyword of
    

    public static void main(String args[])

via Java interview questions and answers | TechInterviews.

# What does the command ‘use strict’ do and why should you use it?

# What do the symbols $ @ and % mean when prefixing a variable?

# What elements of the Perl language could you use to structure your code to allow for maximum re-use and maximum readability?

# What are the characteristics of a project that is well suited to Perl?

# Why do you program in Perl?

# Explain the difference between my and local.

# Explain the difference between use and require.

# What’s your favorite module and why?

# What is a hash?

# Write a simple (common) regular expression to match an IP address, e-mail address, city-state-zipcode combination.

# What purpose does each of the following serve: -w, strict, -T ?

# What is the difference between for & foreach, exec & system?

# Where do you go for Perl help?

# Name an instance where you used a CPAN module.

# How do you open a file for writing?

# How would you replace a char in string and how do you store the number of replacements?

# When would you not use Perl for a project?

via Perl interview questions and answers | TechInterviews.