in reply to Short example using IPC::Open2 or IPC::Open3

Although you want to study IPC::Open2, IMO it is good to know that your problem is solved by a two-line batch file and scp: 
#!/bin/sh
scp -B -i keyfile -r user@host:./foo localdir
scp -B -i keyfile -r localdir user@host:./bar

[download]
     s;;Just-me-not-h-Ni-m-P-Ni-lm-I-ar-O-Ni;;tr?IerONim-?HAcker ?d;print

In Section Seekers of Perl Wisdom