Question

I am uploading a file via ftp using expect. The file is piped into my bash script.

#!/bin/bash
HOST='example.com'
USER='XXX'
PASSWD='XXX'

expect << EOT
spawn ftp $HOST
expect "Name*:"
send "$USER\r"
expect "Password:"
send "$PASSWD\r"
expect "ftp>"
send "binary\r"
expect "ftp>"
send "prompt\r"
expect "ftp>"
send "put - $1\r"  ####
expect "ftp>"
send "bye\r"
expect eof
EOT

On the highlighted line I want ftp to get access to the main script stdin.

Thank you

Answer 1

I believe the key to what you are looking for is Expect’s interact command. You’d get a script like this:

#!/usr/bin/env expect

# Set these in the Tcl way, not the bash way
set HOST "example.com"
set USER "XXX"
set PASSWD "YYY"

# You should recognize this bit...
spawn ftp $HOST
expect "Name*:"
send "$USER\r"
expect "Password:"
send "$PASSWD\r"
expect "ftp>"
send "binary\r"
expect "ftp>"
send "prompt\r"
expect "ftp>"

# New stuff starts here
send "put - [lindex $argv 0]\r"
interact {
    "ftp>" { return }
}
send "bye\r"
wait
exit

I’ve rewritten your script so it doesn’t use a here document, because that would have interfered with the reading of the content (here-docs are presented as stdin…) and switched it to use a few more idiomatic ways of doing things (idiomatic argument access being the main one).

That said, if I was doing this sort of thing for real, I’d look into using the ftp package from Tcllib as that talks the protocol directly instead of using a possibly-problematic subprocess. (Indeed, if you were going to be doing this on Windows, you’d have to do it that way because of quirks of how Expect and http://FTP.EXE work on that platform).