Interview Questions.

Top 100+ Perl Scripting Interview Questions And Answers

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Top 100+ Perl Scripting Interview Questions And Answers

Question 1. Define Perl Scripting?

Answer :

In the IT marketplace, Perl scripting is considered as a sturdy scripting language that is utilized in various fields. Perl is good at obtaining Regular expressions and in all the fields of software it's far specific. Perl is a scripting language which is primarily based on interpreter however no longer on the languages primarily based on compiler. In all of the programs, optimization is used.

Question 2. Why To Use Perl Scripting?

Answer :

Perl scripting is specifically utilized in purposeful standards in addition to ordinary expressions, you could also layout own policies to gain generalized pattern the usage of ordinary expression. Perl is like minded or helps extra than seventy six operating structures and 3000 modules and it's far known as Comprehensive Perl Archive Network modules.

Shell Scripting Interview Questions
Question 3. What Is Perl?

Answer :

Perl is a programming language that is based totally on shell, C, Lisp, and many others. In popular, Perl is mainly used for community operations, OS program and for developing a few websites.

Question 4. Why To Use Perl?

Answer :

• It is a effective interpreter without spending a dime.
• Perl is bendy and portable. It may be very clean to examine Perl language.

Perl Scripting Tutorial
Question 5. Why Do You Create An Application For Real Time System In Which Processing Speed Is Vital?

Answer :

Perl is used inside the following instances:
• To system large textual content
• When records manipulation is completed by way of utility
• If you require fast developments make bigger to emerge as libraries
• To load database operations

Python Interview Questions
Question 6. Which Is Your Favorite Module And Why It Is?

Answer :

CGI.Pm is my favored module and it handles numerous responsibilities which includes printing the headers, parsing the form enter and it handles sessions and cookies correctly.

Question 7. How Perl Warnings Are Turn On And Why Is It Important?

Answer :

In general, Perl excuse unusual and also incorrect code every now and then. Thus, the time spent for searching weird consequences and insects in very excessive. You can become aware of common mistakes and strange places within the code without difficulty while warnings are grew to become on. In the long run, the time required for debugging is saved plenty. There are numerous methods to turn at the warnings of Perl:

-w alternative is used at the command line for Perl one-liner
-w alternative on shebang line is used on home windows or UNIX. Windows Perl interpreter do no longer require it.
For different structures, compiler documentation is checked or compiler warnings are decided on.
Shell Scripting Tutorial IBM - CGIDEV2 Interview Questions
Question eight. Differentiate Use And Require?

Answer :

Use:

This method is used for modules.
The items which can be covered are varied at compilation time.
You need not supply a document extension.
Require:

This technique is used for each modules and libraries.
The items are included are verified at run time.
You want no longer give record extension.
Question nine. Distinguish My And Local?

Answer :

The variables which are declared the usage of “my” lives most effective in that particular block ion which they may be declared and inherited features do now not have a visibility that are known as in that block. The variables that are described as “nearby” are seen in that block and they have a visibility in capabilities which can be referred to as in that particular block.

SQL Server 2000 Interview Questions
Question 10. Why Perl Patterns Are Not Regular Expressions?

Answer :

Perl styles have returned references
By the definition, a normal expression must decide subsequent country endless automation with out extra money to hold in preceding state. State machine is required via the sample / ([ab] +) c1/ to consider old states. Such styles are disqualified as being ordinary expressions within the term’s conventional sense.

Python Tutorial
Question eleven. What Happens If A Reference Is Returned To Private Variable?

Answer :

Your variables are stored on track by means of the Perl, whether dynamic or else, and does not unfastened matters before you operate them.

C++ Interview Questions
Question 12. Define Scalar Data And Variables?

Answer :

The concept of statistics types is flexible, that is found in Perl. Scalar is a unmarried element such as a string or a range of. The java principles inclusive of int, drift, string, and double are similar to scalar concept of Perl. Strings and numbers are exchangeable. Scalar variable is nothing however a Perl variable that is used to store scalar data. A greenback signal $ is used by it that's accompanied with the aid of underscores or alphanumeric characters. It is a case touchy.

Shell Scripting Interview Questions
Question 13. Why -w Argument Is Used With Perl Programs?

Answer :

-w choice of the interpreter is utilized by maximum of the Perl developers particularly within the development stage of an utility. It is caution option to turn on multiple caution messages that are beneficial in information and debugging the utility.

C++ Tutorial
Question 14. Which Has Highest Precedence In Between List And Terms? Explain?

Answer :

In Perl, the best priority is for Perl. Quotes, variables, expressions in parenthesis are included within the Terms. The equal level of priority as Terms is for List operators. Especially, those operators have robust left phrase priority.

Question 15. Define A Short Circuit Operator?

Answer :

The C-fashion operator ll includes out logical operation that is used to tie logical clauses, standard value of true is back if either clause is authentic. This operator is called short-circuit operator due to the fact you need not test or examine right operand if the left operand is real.

C Interview Questions
Question 16. In Perl, Name Different Forms Of Goto And Explain?

Answer :

In Perl, there are 3 different bureaucracy for goto, they're:
• goto name
• goto label
• goto expr
goto name is used at the side of subroutines, it's far used simplest when it is required as it creates destruction in packages. It is the second one shape of label where Execution is transferred to a assertion classified LABEL the use of goto LABEL. The ultimate label form is goto EXPR which expects EXPR to assess label.

C Tutorial
Question 17. Can You Add Two Arrays Together?

Answer :

Yes, it is feasible to feature two arrays collectively with a push characteristic. A fee or values to quit of the array is brought the usage of push feature. The values of listing are driven on to the give up of an array using push characteristic. Length of listing is used to growth duration of an array.

AWK Interview Questions
Question 18. How Shift Command Is Used?

Answer :

The first fee of an array shifted the usage of shift array characteristic and it's miles back, which leads to array shortening via one detail and actions the entirety from a place to left. If an array isn't always particular to shift, shift makes use of @ ARGV, the command line arguments of an array is passed to script or to an array named @.

Python Interview Questions
Question 19. Explain Different Types Of Eval Statements?

Answer :

In fashionable, there are two styles of eval statements they may be:
• Eval BLOCK and
• Eval EXPR
An expression is executed by using eval EXPR and BLOCK is executed by using eval BLOCK. Entire block is completed by eval block, BLOCK. When you need your code passed in expression then first one is used and to parse code in the block, 2d one is used.

AWK Tutorial
Question 20. Describe Returning Values From Subroutines?

Answer :

The price of final expression that is evaluated is the go back cost of subroutine or explicitly, a again statement may be used to go out subroutine which specifies return price. This go back fee is evaluated in best content primarily based on content material of subroutine call.

 

CGI Programming Interview Questions
Question 21. What Are The Two Different Types Of Data Perl Handles?

Answer :

Perl handles  forms of records they are
(i) Scalar Variables and
(ii) Lists
Scalar variables preserve a unmarried records object while lists maintain multiple records gadgets.

Question 22. What Are Scalar Variables?

Answer :

Scalar variables are what many programming languages check with as easy variables. They keep a unmarried facts item, a variety of, a string, or a perl reference. Scalars are called scalars to distinguish them from constructs which could keep more than one object, like arrays.

WxPython Tutorial
Question 23. Explain About Lists?

Answer :

A list is a assemble that associates statistics factors collectively and you can specify a list by means of enclosing the ones factors in parenthesis and setting apart them with commas. They should themselves be arrays, hashes or even other lists. Lists do not have a specific listing information type.

WxPython Interview Questions
Question 24. Name All The Prefix Dereferencer In Perl?

Answer :

The symbol that starts offevolved all scalar variables is known as a prefix dereferencer. The specific styles of dereferencer are.
(i) $-Scalar variables
(ii) %-Hash variables
(iii) @-arrays
(iv) &-subroutines
(v) Type globs-*myvar stands for @myvar, %myvar.

IBM - CGIDEV2 Interview Questions
Question 25. Explain About An Ivalue?

Answer :

An ivalue is an item that may serve as the target of an project. The term I cost in the beginning intended a “left fee”, that's to say a value that appears at the left. An ivalue generally represents a facts space in reminiscence and you may shop information the usage of the ivalues call. Any variable can serve as an ivalue.

Unix/Linux Tutorial
Question 26. How Does A "grep" Function Perform?

Answer :

Grep returns the number of traces the expression is real. Grep returns a sub listing of a list for which a particular criterion is actual. This function regularly entails sample matching. It modifies the factors within the authentic listing.

Unix/Linux Interview Questions
Question 27. Explain About Typeglobs?

Answer :

Type globs are another vital kind in perl. A typeglob`s prefix derefrencer is *, which is also the wild card character because you may use typeglobs to create an alias for every type related to a selected call. All types of manipulations are possible with typeglobs.

SQL Server 2000 Interview Questions
Question 28. Is There Any Way To Add Two Arrays Together?

Answer :

Of path you can add  arrays together through the usage of push feature. The push function adds a value or values to the stop of an array. The push feature pushes the values of listing onto the quit of the array. Length of an array can be extended by means of the length of list.

Unix socket Tutorial
Question 29. How To Use The Command Shift?

Answer :

Shift array characteristic shifts off the first fee of the array and returns it, thereby shortening the array by way of one element and moving everything from one area to the left. If you don’t specify an array to shift, shift uses @ ARGV, the array of command line arguments surpassed to the script or the array named @-.

Unix socket Interview Questions
Question 30. What Exactly Is Grooving And Shortening Of The Array?

Answer :

You can trade the variety of elements in an array certainly via changing the value of the ultimate index of/inside the array $#array. In reality, in case you absolutely confer with a nonexistent element in an array perl extends the array as needed, developing new elements. It also consists of new elements in its array.

Question 31. What Are The Three Ways To Empty An Array?

Answer :

The 3 distinctive methods to drain an array are as follows
1) You can empty an array with the aid of putting its period to a terrible quantity.
2) Another way of empting an array is to assign the null list ().
3) Try to clear an array by way of putting it to undef, but be aware while you set to undef.

Unix makefile Tutorial
Question 32. How Do You Work With Array Slices?

Answer :

An array slice is a section of an array that acts like a list, and also you indicate what elements to position into the slice by using the usage of more than one array indexes in rectangular brackets. By specifying the variety operator you can also specify a slice.

Python Automation Testing Interview Questions
Question 33. What Is Meant By Splicing Arrays Explain In Context Of List And Scalar.

Answer :

Splicing an array approach adding factors from a list to that array, in all likelihood changing elements now in the array. In listing context, the splice function returns the elements removed from the array. In scalar context, the splice feature returns the final element removed.

C++ Interview Questions
Question 34. What Are The Different Types Of Perl Operators?

Answer :

There are 4 extraordinary sorts of perl operators they are
(i) Unary operator just like the now not operator
(ii) Binary operator just like the addition operator
(iii) Tertiary operator just like the conditional operator
(iv) List operator just like the print operator

Question 35. Which Has The Highest Precedence, List Or Terms? Explain?

Answer :

Terms have the very best precedence in perl. Terms include variables, rates, expressions in parenthesis etc. List operators have the equal degree of priority as phrases. Specifically, these operators have very robust left word priority.

Question 36. What Is Perl Scripting?

Answer :

Perl Scripting is one of the strong scripting languages inside the IT market that's being used in “n” of fields. Perl is rich in finding Regular expressions and stands unique in all fields of application.

PERL is a scripting language. Since all scripting languages are interpreter based languages however now not compiler based totally languages, we use for optimization of code in all software.

C Interview Questions
Question 37. Why Do We Use Perl Scripting?

Answer :

We use PERL scripting because it's far wealthy in all normal expressions and useful standards, we can create our personal regulations to discover specific generalized sample through the usage of regular expression. PERL supports or well matched in almost 76+ Operating systems and supports more than 3000 modules, referred to as as CPAN (Comprehensive Perl Archive Network) modules.

Question 38. What Is A Subroutine?

Answer :

Subroutine is perl is a block of code specifically mixed/grouped to carry out a selected challenge.Which may be known as at any point of time in a perl application.
Advantage using Subroutine
a) allows in modular programming making it less difficult to recognize and keep.
B)gets rid of duplication through reusing the same code/calling the subroutine.

Question 39. Name An Instance You Used In Cpan Module?

Answer :

CGI, DBI etc are very not unusual applications used from CPAN. There are hundreds of other beneficial modules.

Question forty. I Have A Variable Named $objref Which Is Defined In Main Package. I Want To Make It As A Object Of Class Xyz. How Could I Do It?

Answer :

use XYZ;
my $objref= XYZ->new();

AWK Interview Questions
Question forty one. What Is Meant 'die' In A Perl Program?

Answer :

If the condition described earlier than the DIE assertion is NOT met, the script will stop execution at that factor, printing out the default mistakes, if a custom errors message is not described.

Question 42. What Is Hash In Perl?

Answer :

Hash in essentially used to comment the script line.
A hash is and unordered set of key/cost pairs which you get entry to using strings (keys) as subscripts, to look up the scalar fee similar to a given key.

CGI Programming Interview Questions
Question 43. What Does This Mean :
'$_' ?

Answer :

Default variable in Perl.
Its an Default variable in Perl, in which the input from the user will be taken into this variable if the variable is not defined through the person.

Question 44. What Is A Datahash(). What Does It Mean? And For What Purpose It Is Used??

Answer :

In Win32::ODBC, DataHash() characteristic is used to get the records fetched thru the square announcement in a hash format.

Question 45. Explain About Returning Values From Subroutines (functions)?

Answer :

The return value of the subroutine is the price of the closing expression evaluated or you can explicitly use a go back announcement to go out the subroutine specifying the go back cost. That go back fee is evaluated in the appropriate content depending on the content of the subroutine call.

Question forty six. What Is Meant By A 'percent' In Perl?

Answer :

Pack Converts a listing right into a binary illustration
Takes an array or list of values and packs it right into a binary structure, returning the string containing the structure
Hope that kills the trouble
Question forty seven. How Do You Connect To Database In Perl

Answer :

There is DBI module. Use DBI;my $dbh = DBI->connect('dbi:Oracle:orcl', 'username', 'password',)wherein username and password is yours. This is example for oracle database.

For Sybase:
use DBI;
my $dbh = DBI->connect('dbi:Sybase:server=$SERVER', 'username', 'password')

Question 48. What Is A Short Circuit Operator?

Answer :

The C-Style operator, ll, plays a logical (or) operation and you can use it to tie logical clauses together, returning an basic value of genuine if either clause is actual. This operator is called a brief-circuit operator because if the left operand is authentic the proper operand isn't checked or evaluated.

Question 49. How To Connect With Sqlserver From Perl And How To Display Database Table Info?

Answer :

There is a module in perl named DBI - Database unbiased interface so one can be used to connect to any database with the aid of the use of same code. Along with DBI we should use database precise module right here it's far SQL server. For MSaccess it's miles DBD::ODBC, for MySQL it is DBD::mysql driver, for integrating oracle with perl use DBD::oracle motive force is used. IIy for SQL server there are to be had many custom defined ppm( perl package supervisor) like Win32::ODBC, mssql::oleDB and so forth.So, together with DBI, mssql::oleDB we can access SQL server database from perl. The instructions to access database is identical for any database.

Question 50. What Value Is Returned By A Lone Return; Statement?

Answer :

The undefined value in scalar context, and the empty list price () in list context. This way capabilities that wish to return failure can just use a simple return without worrying approximately the context wherein they were called.

Question fifty one. How To Turn On Perl Warnings? Why Is That Important?

Answer :

Perl may be very forgiving of peculiar and from time to time incorrect code, which could imply hours spent trying to find insects and weird effects. Turning on warnings helps uncover common mistakes and bizarre locations and shop a lot of debugging time in the end. There are various approaches of turning on Perlwarnings:

* For Perl one-liner, use -w alternative at the command line.
* On Unix or Windows, use the -w option in the shebang line (The first # line within the script). Note: Windows Perl interpreter might not require it.
* For different structures, choose compiler warnings, or check compiler documentation.

Question fifty two. Write A Script To Reverse A String Without Using Perl's Built In Functions?

Answer :

my $txt = 'Hello World';
my $len= duration($txt);
my $rev;
whilst($len > 0)
$len--;
$rev .= substr($txt,$len,1);

print $txt, ' - Reversed = ' , $rev;

Question 53. What Is Perl One-liner?

Answer :

There are two approaches a Perl script can be run:
--from a command line, called one-liner, that means you kind and execute right away at the command line. You'll want the -e choice to start like "C: %gt perl -e "print "Hello";". One-liner would not suggest one Perl announcement. One-liner may include many statements in a single line.
--from a script report, known as Perl program.

Question 54. What Are The Different Types Of Eval Statements?

Answer :

There are two extraordinary forms of eval statements they are eval EXPR and eval BLOCK.
Eval EXPR executes an expression and eval BLOCK executes BLOCK. Eval Block executes an entire block, BLOCK. First one is used while you want your code surpassed within the expression and the second is used to parse the code within the block.

Question fifty five. What Is Your Experience Of Interfacing Perl To Database?

Answer :

The correct answer is DBI

Question 56. What Is Cpan ? What Are The Modules Coming Under This?

Answer :

CPAN is Comprehensive Perl Archive Network. It’s a repository includes thousands of Perl modules, supply and documentation, and all beneath GNU/GPL or comparable license. Some Linux distributions provide a tool named "cpan" with which you could set up packages immediately from CPAN

Question 57. Given A File, Count The Word Occurrence (case Insensitive)?

Answer :

open(FILE,"filename");
@array=; $wor="phrase to be discovered";
$rely=0; foreach $line (@array)  @arr=split (/s+/,$line);
foreach $phrase (@arr)  if ($phrase =~ /s*$wors*/i) $be counted=$count number+1;  

print "The phrase happens $rely times";

Question 58. How Do I Set Environment Variables In Perl Programs?

Answer :

As you could remember, "%ENV" is a unique hash in Perl that consists of the fee of all your environment variables.

Because %ENV is a hash, you may set environment variables just as you would set the fee of any Perl hash variable. Here's how you may set your PATH variable to make sure the subsequent four directories are on your route::

$ENV'PATH' = '/bin:/usr/bin:/usr/local/bin:/domestic/yourname/bin';

Question fifty nine. Why We Use Perl?

Answer :

1.Perl is a effective free interpreter.
2.Perl is portable, bendy and clean to analyze.

-For shell scripting
-For CGI
-Tons of scripts are to be had.
-Easy development
-Enormous large aid script archive like CPAN
-No one starts to write a Perl scripts from scratch, you choose one from an archive and modify that.
-It is a "mature" scripting language.
-You may additionally discover Perl interpreter on every venture important environment
-Easy to learn

Question 60. Why Does Perl Not Have Overloaded Functions?

Answer :

Because you can check out the argument count, return context, and item types all through your self.
In Perl, the range of arguments is trivially available to a feature thru the scalar feel of @_, the go back context via want array(), and the sorts of the arguments through ref() if they're references and easy sample matching like /^d+$/ otherwise. In languages like C++ where you cannot do this, you in reality have to lodge to overloading of features.

Question 61. Which Of These Is A Difference Between C++ And Perl?

Answer :

Perl could have objects whose facts cannot be accessed outdoor its magnificence, however C++ cannot.
Perl can use closures with unreachable private records as items, and C++ would not aid closures. Furthermore, C++ does aid pointer arithmetic thru `int *ip = (int*)&item', allowing you do look all around the item. Perl would not have pointer mathematics. It also does not permit `#outline non-public public' to trade access rights to overseas objects. On the alternative hand, once you start poking around in /dev/mem, nobody is secure.

Question sixty two. How To Concatenate Strings With Perl?

Answer :

Method #1 - the use of Perl's dot operator:
$call = 'checkbook';
$filename = "/tmp/" . $name . ".Tmp";

Method #2 - using Perl's be a part of characteristic
$name = "checkbook";
$filename = be part of "", "/tmp/", $call, ".Tmp";

Method #3 - regular way of concatenating strings
$filename = "/tmp/$name.Tmp";

Question sixty three. What Is The Difference Between Chop & Chomp Functions In Perl?

Answer :

chop is used to eliminate final man or woman,chomp characteristic gets rid of simplest line endings.

Question 64. What Is Hash?

Answer :

Hash is an associative array where facts is stored in
"key"->"cost" pairs.
Eg : culmination is a hash having their names and charge
%fruits = ("Apple", "60", "Banana", "20", "Peers", "forty");

Question sixty five. How Would You Replace A Char In String And How Do You Store The Number Of Replacements?

Answer :

$str='Hello';
$cnt= ($str=~s/l/i/g);
print $cnt;

Question sixty six. How Do You Open A File For Writing?

Answer :

open FILEHANDLE, ">$FILENAME"

Question 67. What's Your Favorite Module And Why?

Answer :

My Favourite module is CGI.Pm Bcoz it is able to take care of nearly all the duties like
1. Parsing the shape input
2. Printiing the headers
3. Can take care of cookies and classes and much more

Question 68. How To Implement Stack In Perl?

Answer :

Stack is LIFO (Last in First out), In perl that would be inplemented the use of the push() and shift() functions. Push() adds the detail at the final of array and shift() removes from the start of an array.

Question sixty nine. Why Do You Program In Perl?

Answer :

Perl is simple, speedy and its a laugh to code in perl.
Perl is rich with diverse applications, N/w programming could be very easy and there are lot extra advantages to mention.

Question 70. How We Can Navigate The Xml Documents?

Answer :

You can use SAX if what you require is simple accesing of the xml shape. You can cross for DOM in case you need node managing competencies like putting a node, enhancing a node, deleteing node and stuff like that.

Question seventy one. Help In Perl?

Answer :

perldoc -f print

Question 72. What Is The Use Of "stderr()"?

Answer :

STDERR:
The unique filehandle for preferred errors in any package.

Question 73. Advantages Of C Over Perl?

Answer :

In fact PERL interpreter is written in C. So what all benefits C have are also possesed by using PERL. Otherwise C is quicker than PERL, due to the fact PERL is an interpreted language.

Question seventy four. Perl Regular Expressions Are Greedy" What Does This Mean?

Answer :

Perl everyday expressions commonly in shape the longest string viable. That is what is called as "greedy suit"

Question 75. What Does The Word '&myvariable' Mean?
What Does The Symbol '&' Means? What's Purpose Of It?

Answer :

&myvariable is asking a sub-habitual.

& is used to perceive a sub-recurring.

Question seventy six. What Is Super?

Answer :

Super refers to present day bundle ancestor.

Question seventy seven. What Is Rpc? Why Do I Need It?

Answer :

RPC:A call to a procedure in a one-of-a-kind cope with area. In a traditional method name, the calling technique and the known as process are inside the identical cope with space on one system. In a remote process call, the calling manner invokes a system in a exclusive cope with area and generally on a unique gadget.

Question 78. What Does Init 5 And Init zero Do?

Answer :

init 5 will shutdown and Power-off the server.

Init 0 will convey the server to the ok> activate (Fourth monitor)

Question seventy nine. What Does Ndd Do?

Answer :

ndd command will hardcore the velocity of the community interface card.

Question 80. What Is Obp And How Do You Access It?

Answer :

OBP is known as as Open Boot PROM. This OBP can be accessiable through good enough> spark off

Question 81. How Do You Boot From Cd-rom?

Answer :

Booting form CD-ROM may be accomplished by means of the command
adequate >boot cdrom

Question 82. What Is /and so forth/machine For?

Answer :

/and many others/machine is a kernal report of Solaris OS.

Question 83. How Do You Boot From A Network With Jumpstart?

Answer :

boot internet - install

Question 84. What Is Jumpstart?

Answer :

The Jumpstart function is an automated set up process available inside the Solaris operating surroundings. It allows gadget directors to categorize machines on their network and mechanically deploy systems based totally at the class to which a system belongs.

Question 85. What Is Lom

Answer :

Short for LAN on motherboard. The time period refers to a chip or chipset capable of network connections that has been embedded at once on the motherboard of a computer, workstation or server. Instead of requiring a separate network interface card to get admission to a nearby-region community, including Ethernet, the circuits are connected to the motherboard. An advantage of a LOM machine is an additional available PCI slot that is not being used by the community adapter.

Question 86. How To Create A Package?

Answer :

pkgmk -o -r / -d /tmp -f Prototype

Question 87. How Do You View Shared Memory Statistics?

Answer :

swap -l -> presentations change utilization
prstat -> examines all lively strategies at the gadget and reviews records based
on the chosen output mode and sort order
vmstat -> reports information approximately processes, reminiscence, paging, block IO, traps,
and cpu activity
pmap -> lists the digital reminiscence mappings underlying the given manner

Question 88. What Is Vts?

Answer :

Sun Validation Test Suite -> tests and validates Sun hardware by way of verifying the configuration and functionality of hardware controllers, gadgets

Question 89. What Is Grep Used For In Perl?

Answer :

Grep is used with everyday expression to check if a parituclar cost exist in an array. It returns 0 if the fee does now not exists, 1 otherwise.

Question ninety. How To Code In Perl To Implement The Tail Function In Unix?

Answer :

You must preserve a structure to shop the line number and the dimensions of the record at that time eg. 1-10bytes, 2-18bytes.. You've got a counter to boom the wide variety of lines to find out the number of traces in the report. Once you are thru the document, you'll know the size of the file at any nth line, use 'sysseek' to move the file pointer returned to that role (ultimate 10) and then start analyzing until the give up.

Question 91. What Are The Arguements We Normally Use For Perl Interpreter

Answer :

-e for Execute, -c to compile, -d to name the debugger on the document special, -T for traint mode for safety/enter checking -W for display all warning mode (or -w to show less caution)

Question 92. What Is It Meants By '$_'?

Answer :

it is a default variable which holds mechanically, a list of arguements passed to the subroutine within parenthesis.

Question 93. What Is The Tk Module?

Answer :

it affords a GUI interface.

Question ninety four. How To Concatinate Strings In Perl?

Answer :

via . Operator

Question ninety five. What Value Is Returned By A Lone 'go back;' Statement?

Answer :

The undefined fee in scalar context, and the empty list value () in list context. This way capabilities that wish to return failure can just use a simple return without disturbing about the context in which they had been called.

Question 96. How Do Find The Length Of An Array?

Answer :

$@array

Question 97. What Does Read() Return At End Of File?

Answer :

A defined (but fake) 0 cost is the proper indication of the give up of report for study() and sysread().

Question 98. How Do You Print Out The Next Line From A Filehandle With All Its Bytes Reversed?

Answer :

print scalar opposite scalar Surprisingly sufficient, you need to positioned each the opposite and the into scalar context one by one for this to work.

Question 99. What Does Perl Do If You Try To Exploit The Execve(2) Race Involving Setuid Scripts?

Answer :

Sends mail to root and exits. It has been said that every one programs advance to the point of being able to routinely study mail. While not pretty at that point (nicely, without having a module loaded), Perl does as a minimum mechanically ship it.

Question 100. What Are Scalar Data And Scalar Variables?

Answer :

Perl has a flexible concept of records kinds. Scalar method a single element, like more than a few or string. So the Java concept of int, waft, double and string equals to Perl's scalar in idea and the numbers and strings are exchangeable. Scalar variable is a Perl variable that is used to save scalar information. It makes use of a dollar signal $ and observed via one or extra aphanumeric characters or underscores. It is case sensitive.

Question 101. How To Start Perl In Interactive Mode?

Answer :

perl -e -d 1 PerlConsole.

Question 102. What Package You Use To Create A Windows Services?

Answer :

use Win32::OLE.

Question 103. What Is A Datahash()

Answer :

in Win32::ODBC, DataHash() feature is used to get the facts fetched through the square declaration in a hash format.

Question 104. What Does This Symbol Mean '->'?

Answer :

In Perl it's far an infix dereference operator. For array subscript, or a hash key, or a subroutine, then this ought to be a reference. Can also be used as method invocation.

Question one hundred and five. What Is Cpan?

Answer :

CPAN is comprehensive Perl Archive Network. Its a repository includes heaps of Perl Modules, supply and documentation, and all beneath GNU/GPL or smilar licence. Some linux distribution offer a until names 'cpan'; which you can install packages directly from cpan.

Question 106. What Is The Difference Between Exec And System?

Answer :

exec runs the given method, switches to its call and in no way returns while system forks off the given system, waits for its to complete after which return.

Question 107. What Is The Difference Between For And Foreach?

Answer :

functionally, there may be no distinction between them.

Question 108. What Is A Regular Expression?

Answer :

it defines a sample for a search to match.

Question 109. What Is Stderr() In Perl?

Answer :

special document handler to traditional mistakes in any package.

Question one hundred ten. List The Files In Current Directory Sorted By Size ?

Answer :

- ls -l kind -nr




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