perl error handling

In Perl, error handling can be done using the die function or by using eval to trap and handle errors. Here's an example of how to use die:

#!/usr/bin/perl

use strict;
use warnings;

my $filename = "example.txt";

# Open the file or die with an error message
open(my $fh, "<", $filename) or die "Can't open file $filename: $!";

# Read the contents of the file into an array
my @lines = <$fh>;

# Close the file
close($fh);

In this example, we use the die function to print an error message if the file cannot be opened. If the file cannot be opened, the die function will print the error message and terminate the program.

Another way to handle errors is to use eval to trap and handle exceptions:

#!/usr/bin/perl

use strict;
use warnings;

my $filename = "example.txt";

# Try to open the file
eval {
    open(my $fh, "<", $filename) or die "Can't open file $filename: $!";
    # Read the contents of the file into an array
    my @lines = <$fh>;
    # Close the file
    close($fh);
};

# Check for errors
if ($@) {
    print "Error: $@";
}

In this example, we use eval to wrap the code that could potentially generate an error. If an error occurs, it will be trapped and stored in the special $@ variable. We can then check if $@ is true, which indicates that an error occurred. If an error did occur, we print the error message using print.

Note that when using eval, it's important to be careful about what code you wrap in the eval block. If the code generates a fatal error, such as a syntax error or a segmentation fault, eval will not be able to trap it. Therefore, it's generally recommended to use eval only for code that could potentially generate recoverable errors, such as I/O operations or network communications.