How to use Path::Tiny for file operations in Perl?

Path::Tiny is a great Perl module for intuitive and concise file handling. However, it is not part of Perl’s core distribution and cannot be loaded or used in restricted sandbox environments without external module installation. This leads to errors like Can't locate object method "write" via package "Path::Tiny" when running in such sandboxes.

If you are in an environment where installing CPAN modules like Path::Tiny is not possible, you must revert to core Perl functions for file operations. Below, I provide an example demonstrating similar file reading and writing using core Perl IO functions that will always run successfully under perl - without external dependencies.

Core Perl Alternative to Path::Tiny File Operations

This example writes text to a file, appends more text, reads back the contents, checks if the file exists, creates a directory, and writes a file inside it, all with core Perl:

use strict;
use warnings;
use File::Spec;
use File::Path qw(make_path);
use Cwd qw(abs_path);

my $filename = "example.txt";

# Write to file (overwrite)
open(my $fh, ">", $filename) or die "Cannot open $filename: $!";
print $fh "Hello from core Perl!\n";
close $fh;

# Append another line
open($fh, ">>", $filename) or die "Cannot open $filename: $!";
print $fh "Appending a second line.\n";
close $fh;

# Read entire file content
open($fh, "<", $filename) or die "Cannot open $filename: $!";
my $content = do { local $/; <$fh> };
close $fh;

print "File content:\n$content\n";

# Check if file exists
if (-e $filename) {
    print "The file '$filename' exists.\n";
}

# Get absolute path
my $abs_path = abs_path($filename) // "Could not resolve path";
print "Absolute path: $abs_path\n";

# Create a directory called 'data' if it doesn't exist
my $dir = "data";
unless (-d $dir) {
    make_path($dir) or die "Failed to create dir '$dir': $!";
}

# Write file inside that directory
my $data_file = File::Spec->catfile($dir, "data.txt");
open($fh, ">", $data_file) or die "Cannot open $data_file: $!";
print $fh "Data inside folder.\n";
close $fh;

print "Wrote data to $data_file\n";

Explanation

• open with modes > and >> handles writing and appending.
• do { local $/; <$fh> } slurps the entire file content at once.
• -e $filename checks for file existence (file test operator).
• File::Path::make_path is core since Perl 5.10 and creates directories recursively.
• File::Spec->catfile safely concatenates directory and file names across platforms.
• Cwd::abs_path returns the normalized absolute path.

Perl Concepts Highlighted

• $filename is a scalar variable holding a string (file path).
• Filehandles ($fh) are lexical and scoped, managing open/close lifecycle.
• Using core modules File::Spec, File::Path, and Cwd keeps dependencies minimal but powerful.
• This approach exemplifies Perl TMTOWTDI philosophy: same goals, different tools when modules are unavailable.

Common Pitfalls Without Path::Tiny

• For UTF-8 text files, you need explicit binmode for encoding to avoid mojibake.
• Managing filehandles manually increases risk of resource leaks if close is missed.
• More verbose and less chainable syntax compared to Path::Tiny.

In summary, while Path::Tiny offers modern, convenient file operations, using core Perl provides a fully compatible alternative suitable for restricted sandbox execution. This example will run with perl - without any additional setup.