How do you use safe shelling out (system, open |- , IPC::Run) with a short example?

In Perl, safely executing external commands is crucial to ensure your script is secure and behaves as expected. Here, we cover three common methods for shelling out safely: using the `system`, `open`, and `IPC::Run` modules. Each approach has its own use cases and benefits.

1. Using `system`

The `system` function is used to execute external commands and wait for them to complete. It's important to pass the command and arguments as a list to avoid shell metacharacters being interpreted.

# Example of using system safely my $command = "ls"; my @args = ("-l", "/path/to/directory"); system($command, @args);

2. Using `open` with a pipe

When you want to capture the output of a command, you can use the `open` function with a pipe. This approach allows you to read the command's output directly.

# Example of using open with a pipe my $command = "echo"; my $arg = "Hello World!"; open(my $fh, '-|', $command, $arg) or die "Could not open pipe: $!"; while (<$fh>) { print; # Print each line of output } close($fh);

3. Using `IPC::Run`

The `IPC::Run` module provides a powerful way to run and communicate with external processes. It can handle input/output and is more versatile for complex interactions.

# Example of using IPC::Run use IPC::Run 'run'; my $command = "echo"; my $arg = "Hello from IPC::Run!"; run([$command, $arg], \my $out, \my $err); print "Output: $out"; # Print the output

safe shelling out Perl system Perl open pipe Perl IPC::Run execute external commands

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