The Carp Module

It is alternative to warn and die for modules. It is useful for user-defined modules because they act somewhat like die() and warn(), but with a message which is added by the programmer.
This Carp module provides some functions which are:

1. carp()
2. cluck()
3. croak()
4. confess()

carp() function: This function works similar to warn function and prints the message given by the user without exiting the script.
Example:

use test;
functionName();

Output:

Error in module!  at test.pm line 8

cluck() function: This function produces a context which is a summary of every call in the call-stack. It follows the same process as the carp() function does but it prints a stack of all the modules that led to the call to the specific function.
Example:

use Test;
function_name();

Output:

Error in module! at Test.pm line 5
   Test::function_name() called at test.pl line 2

croak() function: This function is similar to die() function, except that it produces a shorter message which reports the error as being from where your module was called.
Example:

use Test;
functionName();

Output:

Error in module! at test.pl line 2

confess() function: This function is similar to cluck() function. It calls the die function and then prints a stack of all the modules that led to the call to the specific function.
Example:

use Test;
functionName();

Output:

Error in module! at Test.pm line 5
   Test::functionName() called at test.pl line 2

Error Handling in Perl is the process of taking appropriate action against a program that causes difficulty in execution because of some error in the code or the compiler. Processes are prone to errors. For example, if opening a file that does not exist raises an error, or accessing a variable that has not been declared raises an error.
The program will halt if an error occurs, and thus using error handling we can take appropriate action instead of halting a program entirely. Error Handling is a major requirement for any language that is prone to errors.

Errors can be classified by the time at which they occur:

1. Compile Time Errors
2. Run Time Errors

Compile Time Error: It is an error such as syntax error or missing file reference that prevents the program from successfully compiling.

Run Time Error : It is an error that occurs when the program is running and these errors are usually logical errors that produce the incorrect output.