Perl stands for ‘Practical Extraction and Reporting Language’. Perl consists of rich features used to write powerful and efficient code for high-end programming. It is a scripting language used to write mission critical-projects.

Perl is a powerful scripting language that consists of the best features of C, sed, sh, and awk. It provides a single platform for system administrators and developers to develop applications. It offers efficiency and ease of executing various complex tasks.

•    Perl scripting language works alongside both procedural and object-oriented programming.
•    It is compatible with Y2K date system. 
•    The database integration interface in Perl supports other databases including Oracle, Sybase, MySQL, and Postgres.
•    Perl uses XS and SWIG to interact with C/C++ libraries. 
•    It is compatible with HTML, XML, and other mark-up languages.
•    Over 20,000 third party modules are available in the comprehensive Perl archive network making Perl an extensible scripting language.

•    Perl is popular for its text manipulation capabilities and rapid development cycle making it the most preferred web programming language.
•    It is used to develop encrypted web data and e-commerce transactions.
•    The processing speed can be increased by embedding Perl into web servers.
•    A Perl interpreter is embedded through Apache web server through mod_perl.

True. Perl is a case-sensitive language.

Perl advantages: 
•    It is an easy-to-use scripting language.
•    It helps in the efficient development of high-end programs.
•    It can run on more than 100 platforms making it a cross-platform and portable language.
•    It is an extendable language allowing to import CPAN modules for supporting database. 
Disadvantage:
•    The main disadvantage of Perl is the many features that it consists making working on it an exhaustive task.
•    As it is an interpreted language it makes the execution process a bit slow.

Scalars, array of scalars and hashes of scalars are the three different datatypes supported by Perl.

Scalar data type: The scalar datatype consists of number, string, or a reference. These datatypes start with a $ sign. They are by default undefined. They are interpreted as TRUE if it is not a null string.

Arrays of scalar: These store a list of scalar values. The list can be accessed by a numeric index and starts with a 0. They start with the @ sign. These constitute the ordered list.

Hashes of scalar: It is an unordered list that can be accessed with the help of keys as subscripts. It is also known as associative arrays and start with a % sign. It uses key-values instead of an index value.

CPAN stands for Comprehensive Perl Archive Network. It has a large collection of all the documents and software related to Perl. Programmers can access useful information from this and implement it while developing applications.

The right-hand side of a list context is evaluated by the assignment to an array or a hash.

The reference to a private variable in Perl is tracked and does not free them once they are used.

USE method is used for modules and REQUIRE method is used for modules and libraries. 
In USE method the objects are verified at compilation time while in REQUIRE the objects included are verified at runtime.
It is not necessary to provide any file extension for USE and REQUIRE.

The various numeric operators used in PERL include:
•    Arithmetic operators
•    Bitwise Operators
•    Comparison operators
•    String concatenation

The following are a few of the flags and arguments used in PERL:
e- executes
d- debugging
w- warning
c- compiling
Along with these flags users can implement the combination of different arguments together.

PERL consists of three main control keys:
•    REDO statement
•    NEXT statement
•    LAST statement
16.    What are the steps followed to copy a file in PERL?
Read all the lines of the file into a while loop and copy it into another file. This copies a file in PERL.

PERL warnings are used to check the quality of the code written. Mandatory warnings highlight problems in the lexical analysis stage. Optional warnings highlight cases of possible anomaly.
The –w argument is used in the command line to enable warnings.
Ex: perl –w myscript.pl

Single quoted string is used to print the perl variable as a string. The double quoted string evaluates the variable and get its values.

The array in Perl can be emptied in three different ways: 
•    By setting the length and placing it to a negative number.
•    By assigning a null list ().
•    Setting the array to undef () to empty it.

String manipulation in Perl is carried out by two operators.
Concatenation operator (.): It combines two different strings into one resultant string
Repetition operator (x): Allows the repetition of the string for the specified number of times.

The grep function in Perl used for Pattern matching as in other scripting languages.
The “grep” function works on a list.
It evaluates an expression or a block for each element of the List.
For each statement that returns true as a result of evaluating an expression, it adds that element to the list of returning values.