script < input &
# lsof -p PID 
COMMAND   PID USER   FD   TYPE DEVICE     SIZE    NODE NAME
... cut ...
perl    20316 root    0r   REG    8,2    43151 1564123 /root/av/mail.exploits
perl    20316 root    1u   CHR  136,2                4 /dev/pts/2
perl    20316 root    2u   CHR  136,2                4 /dev/pts/2