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1.Perl is a powerful free interpreter.
2.Perl is PORTABLE, flexible and EASY to learn.

-For shell scripting
-For CGI
-Tons of scripts are available.
-Easy development
-Enormous big support 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 find Perl interpreter on every mission critical environment
-Easy to learn

1.Perl is a powerful free interpreter.
2.Perl is portable, flexible and easy to learn.

-For shell scripting
-For CGI
-Tons of scripts are available.
-Easy development
-Enormous big support 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 find Perl interpreter on every mission critical environment
-Easy to learn

As you may remember, "%ENV" is a special hash in Perl that CONTAINS the VALUE of all your ENVIRONMENT variables.

Because %ENV is a hash, you can SET environment variables just as you'd set the value of any Perl hash variable. Here's how you can set your PATH variable to make SURE the following four directories are in your path::

$ENV{'PATH'} = '/bin:/usr/bin:/usr/local/bin:/home/yourname/bin';

As you may remember, "%ENV" is a special hash in Perl that contains the value of all your environment variables.

Because %ENV is a hash, you can set environment variables just as you'd set the value of any Perl hash variable. Here's how you can set your PATH variable to make sure the following four directories are in your path::

$ENV{'PATH'} = '/bin:/usr/bin:/usr/local/bin:/home/yourname/bin';

open(FILE,"FILENAME");
@ARRAY=; $WOR="word to be found";
$count=0; FOREACH $line (@array) { @arr=split (/s+/,$line);
foreach $word (@arr) { if ($word =~ /s*$WORS*/i) $count=$count+1; } }

print "The word occurs $count times";

open(FILE,"filename");
@array=; $wor="word to be found";
$count=0; foreach $line (@array) { @arr=split (/s+/,$line);
foreach $word (@arr) { if ($word =~ /s*$wors*/i) $count=$count+1; } }

print "The word occurs $count times";

CPAN is Comprehensive Perl Archive Network. It’s a repository CONTAINS THOUSANDS of Perl modules, source and documentation, and all under GNU/GPL or similar LICENSE. Some LINUX distributions provide a TOOL named "cpan" with which you can install packages directly from CPAN

CPAN is Comprehensive Perl Archive Network. It’s a repository contains thousands of Perl modules, source and documentation, and all under GNU/GPL or similar license. Some Linux distributions provide a tool named "cpan" with which you can install packages directly from CPAN

The CORRECT ANSWER is DBI

The correct answer is DBI

There are two different types 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 when you want your CODE PASSED in the expression and the second one is used to PARSE the code in the block.

There are two different types 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 when you want your code passed in the expression and the second one is used to parse the code in the block.

There are two ways a Perl SCRIPT can be run:
--from a command line, called one-liner, that MEANS you type and execute immediately on the command line. You'll need the -E option to start like "C: %gt perl -e "print "HELLO";". One-liner doesn't mean one Perl statement. One-liner may contain many statements in one line.
--from a script file, called Perl PROGRAM.

There are two ways a Perl script can be run:
--from a command line, called one-liner, that means you type and execute immediately on the command line. You'll need the -e option to start like "C: %gt perl -e "print "Hello";". One-liner doesn't mean one Perl statement. One-liner may contain many statements in one line.
--from a script file, called Perl program.

my $TXT = 'Hello World';
my $len= length($txt);
my $REV;
while($len > 0){
$len--;
$rev .= substr($txt,$len,1);
}
print $txt, ' - Reversed = ' , $rev;

my $txt = 'Hello World';
my $len= length($txt);
my $rev;
while($len > 0){
$len--;
$rev .= substr($txt,$len,1);
}
print $txt, ' - Reversed = ' , $rev;

Perl is very forgiving of strange and sometimes wrong CODE, which can mean hours spent searching for bugs and weird results. Turning on warnings helps uncover common mistakes and strange places and save a lot of debugging time in the long RUN. There are various ways of turning on Perlwarnings:

* For Perl one-liner, use -w option on the command line.
* On Unix or Windows, use the -w option in the shebang line (The first # line in the script). NOTE: Windows Perl INTERPRETER MAY not require it.
* For other systems, choose compiler warnings, or check compiler documentation.

Perl is very forgiving of strange and sometimes wrong code, which can mean hours spent searching for bugs and weird results. Turning on warnings helps uncover common mistakes and strange places and save a lot of debugging time in the long run. There are various ways of turning on Perlwarnings:

* For Perl one-liner, use -w option on the command line.
* On Unix or Windows, use the -w option in the shebang line (The first # line in the script). Note: Windows Perl interpreter may not require it.
* For other systems, choose compiler warnings, or check compiler documentation.

The undefined VALUE in scalar context, and the EMPTY list value () in list context. This WAY functions that wish to return failure can just use a SIMPLE return WITHOUT worrying about the context in which they were called.

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

There is a module in PERL named DBI - Database independent interface which will be used to connect to any database by using same code. Along with DBI we should use database specific module here it is SQL server. for MSaccess it is DBD::ODBC, for MySQL it is DBD::mysql driver, for integrating oracle with perl use DBD::oracle driver is used. IIy for SQL server there are AVAILABLE many custom defined ppm( perl PACKAGE MANAGER) like Win32::ODBC, mssql::OLEDB etc.so, together with DBI, mssql::oleDB we can access SQL server database from perl. The commands to access database is same for any database.

There is a module in perl named DBI - Database independent interface which will be used to connect to any database by using same code. Along with DBI we should use database specific module here it is SQL server. for MSaccess it is DBD::ODBC, for MySQL it is DBD::mysql driver, for integrating oracle with perl use DBD::oracle driver is used. IIy for SQL server there are available many custom defined ppm( perl package manager) like Win32::ODBC, mssql::oleDB etc.so, together with DBI, mssql::oleDB we can access SQL server database from perl. The commands to access database is same for any database.

The C-Style OPERATOR, ll, performs a logical (or) operation and you can use it to TIE logical clauses together, returning an overall value of TRUE if either clause is true. This operator is called a short-circuit operator because if the left OPERAND is true the right operand is not checked or evaluated.

The C-Style operator, ll, performs a logical (or) operation and you can use it to tie logical clauses together, returning an overall value of true if either clause is true. This operator is called a short-circuit operator because if the left operand is true the right operand is not checked or evaluated.

There is DBI module. use DBI;my $dbh = DBI->connect('dbi:ORACLE:orcl', 'username', 'password',)where 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')

There is DBI module. use DBI;my $dbh = DBI->connect('dbi:Oracle:orcl', 'username', 'password',)where 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')

• Pack CONVERTS a LIST into a BINARY representation
• Takes an array or list of values and packs it into a binary structure, returning the string CONTAINING the structure
• HOPE that kills the problem

The RETURN VALUE of the subroutine is the value of the last EXPRESSION evaluated or you can EXPLICITLY use a return statement to exit the subroutine specifying the return value. That return value is evaluated in the appropriate content DEPENDING on the content of the subroutine call.

The return value of the subroutine is the value of the last expression evaluated or you can explicitly use a return statement to exit the subroutine specifying the return value. That return value is evaluated in the appropriate content depending on the content of the subroutine call.

In Win32::ODBC, DataHash() FUNCTION is used to get the DATA fetched through the sql STATEMENT in a HASH format.

In Win32::ODBC, DataHash() function is used to get the data fetched through the sql statement in a hash format.

DEFAULT variable in Perl.
Its an Default variable in Perl, where the INPUT from the USER will be taken into this variable if the variable is not defined by the user.

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

HASH in basically used to comment the script line.
A hash is and unordered set of KEY/value pairs that you access using strings (keys) as SUBSCRIPTS, to look up the SCALAR value corresponding to a given key.

Hash in basically used to comment the script line.
A hash is and unordered set of key/value pairs that you access using strings (keys) as subscripts, to look up the scalar value corresponding to a given key.

If the CONDITION defined before the DIE STATEMENT is NOT met, the script will stop EXECUTION at that point, printing out the default ERROR, if a custom error MESSAGE is not defined.

If the condition defined before the DIE statement is NOT met, the script will stop execution at that point, printing out the default error, if a custom error message is not defined.

USE XYZ;
my $OBJREF= XYZ->NEW();

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

CGI, DBI etc are very common PACKAGES used from CPAN. there are THOUSANDS of other useful modules.

CGI, DBI etc are very common packages used from CPAN. there are thousands of other useful modules.

Subroutine is perl is a block of code specially combined/grouped to perform a particular task.Which can be CALLED at any point of time in a perl PROGRAM.
Advantage using Subroutine
a) helps in modular programming MAKING it easier to understand and MAINTAIN.
b)ELIMINATES duplication by reusing the same code/calling the subroutine.

Subroutine is perl is a block of code specially combined/grouped to perform a particular task.Which can be called at any point of time in a perl program.
Advantage using Subroutine
a) helps in modular programming making it easier to understand and maintain.
b)eliminates duplication by reusing the same code/calling the subroutine.

We use PERL scripting because it is rich in all regular EXPRESSIONS and functional concepts, we can create our own rules to find out particular generalized pattern by USING regular EXPRESSION. PERL supports or compatible in almost 76+ Operating systems and supports more than 3000 modules, called as CPAN (Comprehensive Perl ARCHIVE Network) modules.

We use PERL scripting because it is rich in all regular expressions and functional concepts, we can create our own rules to find out particular generalized pattern by using regular expression. PERL supports or compatible in almost 76+ Operating systems and supports more than 3000 modules, called as CPAN (Comprehensive Perl Archive Network) modules.

Perl Scripting is one of the robust scripting LANGUAGES in the IT MARKET which is 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 but not compiler based languages, we use for OPTIMIZATION of code in all application.

Perl Scripting is one of the robust scripting languages in the IT market which is 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 but not compiler based languages, we use for optimization of code in all application.

Terms have the HIGHEST precedence in PERL. Terms include variables, quotes, expressions in parenthesis ETC. List OPERATORS have the same level of precedence as terms. Specifically, these operators have very strong left word precedence.

Terms have the highest precedence in perl. Terms include variables, quotes, expressions in parenthesis etc. List operators have the same level of precedence as terms. Specifically, these operators have very strong left word precedence.

There are four different types of PERL operators they are
(i) Unary operator LIKE the not operator
(ii) Binary operator like the addition operator
(iii) Tertiary operator like the conditional operator
(IV) List operator like the PRINT operator

There are four different types of perl operators they are
(i) Unary operator like the not operator
(ii) Binary operator like the addition operator
(iii) Tertiary operator like the conditional operator
(iv) List operator like the print operator

SPLICING an ARRAY means adding elements from a list to that array, possibly replacing elements now in the array. In list context, the SPLICE function returns the elements removed from the array. In scalar context, the splice function returns the LAST element removed.

Splicing an array means adding elements from a list to that array, possibly replacing elements now in the array. In list context, the splice function returns the elements removed from the array. In scalar context, the splice function returns the last element removed.

An array slice is a SECTION of an array that ACTS like a list, and you indicate what elements to put into the slice by using multiple array indexes in square BRACKETS. By SPECIFYING the range operator you can ALSO specify a slice.

An array slice is a section of an array that acts like a list, and you indicate what elements to put into the slice by using multiple array indexes in square brackets. By specifying the range operator you can also specify a slice.

The three different ways to EMPTY an ARRAY are as follows
1) You can empty an array by setting its length to a negative NUMBER.
2) Another WAY of empting an array is to assign the null list ().
3) Try to clear an array by setting it to undef, but be aware when you set to undef.

The three different ways to empty an array are as follows
1) You can empty an array by setting its length to a negative number.
2) Another way of empting an array is to assign the null list ().
3) Try to clear an array by setting it to undef, but be aware when you set to undef.

You can change the number of ELEMENTS in an array simply by changing the value of the last index of/in the array $#array. In FACT, if you simply refer to a nonexistent ELEMENT in an array perl extends the array as NEEDED, creating new elements. It ALSO includes new elements in its array.

You can change the number of elements in an array simply by changing the value of the last index of/in the array $#array. In fact, if you simply refer to a nonexistent element in an array perl extends the array as needed, creating new elements. It also includes new elements in its array.

Shift array function shifts off the FIRST value of the array and returns it, thereby shortening the array by ONE element and moving everything from one place to the left. If you don’t SPECIFY an array to shift, shift USES @ ARGV, the array of command line arguments passed to the script or the array NAMED @-.

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

Of course you can add two arrays together by using push FUNCTION. The push function ADDS a VALUE or values to the end of an ARRAY. The push function PUSHES the values of list onto the end of the array. Length of an array can be increased by the length of list.

Of course you can add two arrays together by using push function. The push function adds a value or values to the end of an array. The push function pushes the values of list onto the end of the array. Length of an array can be increased by the length of list.

Type globs are another integral type in PERL. A typeglob`s prefix derefrencer is *, which is also the WILD card CHARACTER because you can use typeglobs to create an ALIAS for all types associated with a particular name. All kinds of manipulations are POSSIBLE with typeglobs.

Type globs are another integral type in perl. A typeglob`s prefix derefrencer is *, which is also the wild card character because you can use typeglobs to create an alias for all types associated with a particular name. All kinds of manipulations are possible with typeglobs.

GREP returns the NUMBER of lines the expression is true. Grep returns a sub list of a list for which a specific criterion is true. This function often INVOLVES pattern matching. It modifies the ELEMENTS in the ORIGINAL list.

Grep returns the number of lines the expression is true. Grep returns a sub list of a list for which a specific criterion is true. This function often involves pattern matching. It modifies the elements in the original list.

An ivalue is an item that can serve as the target of an assignment. The term I value ORIGINALLY meant a “left value”, which is to say a value that APPEARS on the left. An ivalue usually represents a data space in memory and you can STORE data using the ivalues NAME. Any variable can serve as an ivalue.

An ivalue is an item that can serve as the target of an assignment. The term I value originally meant a “left value”, which is to say a value that appears on the left. An ivalue usually represents a data space in memory and you can store data using the ivalues name. Any variable can serve as an ivalue.

The SYMBOL that starts all SCALAR variables is called a prefix dereferencer. The different types of dereferencer are.
(i) $-Scalar variables
(ii) %-Hash variables
(iii) @-ARRAYS
(iv) &-subroutines
(v) Type globs-*MYVAR STANDS for @myvar, %myvar.

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

A list is a construct that ASSOCIATES DATA elements together and you can specify a list by ENCLOSING those elements in parenthesis and separating them with commas. They could themselves be arrays, HASHES or even other lists. Lists do not have a specific list data TYPE.

A list is a construct that associates data elements together and you can specify a list by enclosing those elements in parenthesis and separating them with commas. They could themselves be arrays, hashes or even other lists. Lists do not have a specific list data type.

SCALAR variables are what many programming languages refer to as simple variables. They hold a SINGLE data item, a number, a string, or a perl reference. Scalars are CALLED scalars to differentiate them from constructs that can hold more than one item, like ARRAYS.

Scalar variables are what many programming languages refer to as simple variables. They hold a single data item, a number, a string, or a perl reference. Scalars are called scalars to differentiate them from constructs that can hold more than one item, like arrays.

PERL HANDLES two types of data they are
(i) Scalar Variables and
(ii) Lists
Scalar variables hold a single data item whereas lists hold multiple data items.

Perl handles two types of data they are
(i) Scalar Variables and
(ii) Lists
Scalar variables hold a single data item whereas lists hold multiple data items.

The VALUE of LAST expression which is evaluated is the return value of subroutine or explicitly, a returned statement can be used to exit subroutine which SPECIFIES return value. This return value is evaluated in perfect CONTENT BASED on content of subroutine call.

The value of last expression which is evaluated is the return value of subroutine or explicitly, a returned statement can be used to exit subroutine which specifies return value. This return value is evaluated in perfect content based on content of subroutine call.

In general, there are two TYPES of eval statements they are:
• Eval BLOCK and
• Eval EXPR
An expression is executed by eval EXPR and BLOCK is executed by eval BLOCK. ENTIRE block is executed by eval block, BLOCK. When you WANT your code passed in expression then first one is USED and to PARSE code in the block, second one is used.

In general, there are two types of eval statements they are:
• Eval BLOCK and
• Eval EXPR
An expression is executed by eval EXPR and BLOCK is executed by eval BLOCK. Entire block is executed by eval block, BLOCK. When you want your code passed in expression then first one is used and to parse code in the block, second one is used.

The FIRST value of an array shifted using shift array function and it is RETURNED, which RESULTS in array shortening by one element and moves everything from a place to left. If an array is not SPECIFIED to shift, shift uses @ ARGV, the command LINE arguments of an array is passed to script or to an array named @.

The first value of an array shifted using shift array function and it is returned, which results in array shortening by one element and moves everything from a place to left. If an array is not specified to shift, shift uses @ ARGV, the command line arguments of an array is passed to script or to an array named @.

Yes, it is possible to add two ARRAYS TOGETHER with a push function. A value or VALUES to end of the array is added using push function. The values of list are PUSHED on to the end of an array using push function. Length of list is used to increase length of an array.

Yes, it is possible to add two arrays together with a push function. A value or values to end of the array is added using push function. The values of list are pushed on to the end of an array using push function. Length of list is used to increase length of an array.

In PERL, there are three different forms for goto, they are:
• goto name
• goto label
• goto expr
goto name is USED ALONG with subroutines, it is used only when it is required as it creates destruction in programs. It is the second FORM of label where Execution is transferred to a statement labeled LABEL using goto LABEL. The last label form is goto EXPR which expects EXPR to evaluate label.

In Perl, there are three different forms for goto, they are:
• goto name
• goto label
• goto expr
goto name is used along with subroutines, it is used only when it is required as it creates destruction in programs. It is the second form of label where Execution is transferred to a statement labeled LABEL using goto LABEL. The last label form is goto EXPR which expects EXPR to evaluate label.

The C-style OPERATOR ll carries out logical operation which is used to tie logical clauses, overall value of TRUE is RETURNED if either clause is true. This operator is known as short-circuit operator because you NEED not CHECK or evaluate right operand if the left operand is true.

The C-style operator ll carries out logical operation which is used to tie logical clauses, overall value of true is returned if either clause is true. This operator is known as short-circuit operator because you need not check or evaluate right operand if the left operand is true.

In Perl, the highest precedence is for Perl. Quotes, variables, EXPRESSIONS in parenthesis are included in the Terms. The same LEVEL of precedence as Terms is for List operators. ESPECIALLY, these operators have strong left WORD precedence.

In Perl, the highest precedence is for Perl. Quotes, variables, expressions in parenthesis are included in the Terms. The same level of precedence as Terms is for List operators. Especially, these operators have strong left word precedence.

-w OPTION of the interpreter is used by most of the Perl DEVELOPERS especially in the development stage of an application. It is warning option to turn on multiple warning messages that are useful in UNDERSTANDING and DEBUGGING the application.

-w option of the interpreter is used by most of the Perl developers especially in the development stage of an application. It is warning option to turn on multiple warning messages that are useful in understanding and debugging the application.

The concept of data types is flexible, which is present in Perl. Scalar is a single thing such as a string or a NUMBER. The java CONCEPTS such as int, float, string, and DOUBLE are similar to scalar concept of Perl. Strings and numbers are exchangeable. Scalar VARIABLE is nothing but a Perl variable which is used to store scalar data. A dollar sign $ is used by it which is followed by underscores or ALPHANUMERIC characters. It is a case sensitive.

The concept of data types is flexible, which is present in Perl. Scalar is a single thing such as a string or a number. The java concepts such as int, float, string, and double are similar to scalar concept of Perl. Strings and numbers are exchangeable. Scalar variable is nothing but a Perl variable which is used to store scalar data. A dollar sign $ is used by it which is followed by underscores or alphanumeric characters. It is a case sensitive.

Your VARIABLES are KEPT on track by the Perl, WHETHER DYNAMIC or ELSE, and does not free things before you use them.

Your variables are kept on track by the Perl, whether dynamic or else, and does not free things before you use them.

Perl patterns have back references
By the definition, a regular EXPRESSION should determine next state infinite automation without extra money to keep in previous state. State machine is required by the pattern / ([ab] +) C1/ to remember old states. Such patterns are disqualified as being regular expressions in the term’s classic SENSE.

Perl patterns have back references
By the definition, a regular expression should determine next state infinite automation without extra money to keep in previous state. State machine is required by the pattern / ([ab] +) c1/ to remember old states. Such patterns are disqualified as being regular expressions in the term’s classic sense.