expect

[pez@foo ~]$ cat testexpect 
#!/usr/bin/expect -f
gets stdin user
send_user "Got user: $user\n"
[pez@foo ~]$ echo -e "hello\n" | ./testexpect 
Got user: 
[pez@foo ~]$ echo hello | ./testexpect 
Got user: 
[pez@foo ~]$