What's the differences between system and backticks and pipes in Perl?

Question

Perl supports three ways (that I know of) of running external programs:

system:

   system PROGRAM LIST 

as in:

system "abc"; 

backticks as in:

`abc`; 

running it through a pipe as in:

open ABC, "abc|"; 

What are the differences between them? Here's what I know:

1. You can use backticks and pipes to get the output of the command easily.
2. that's it (more in future edits?)

Answer 1

• system(): runs command and returns command's exit status
• backticks: runs command and returns the command's output
• pipes : runs command and allows you to use them as an handle

Also backticks redirects the executed program's STDOUT to a variable, and system sends it to your main program's STDOUT.

Answer 2

The perlipc documentation explains the various ways that you can interact with other processes from Perl, and perlfunc's open documentation explains the piped filehandles.

• The system sends its output to standard output (and error)
• The backticks captures the standard output and returns it (but not standard error)
• The piped open allows you to capture the output and read it from a file handle, or to print to a file handle and use that as the input for the external command.

There are also modules that handle these details with the cross-platform edge cases.