expect script not working in for loop

Question

Need to login to multiple host I am unable to decide how can we add hostname variable in this script array or list. could any one suggest.

And the second thing is that i am getting error while executing this script.

#!/usr/bin/env expect
set timeout 12
set date [exec date "+%d-%B-%Y"]
spawn sh -c "cd /backup/"

for ((i=0;i<8;i++))

do

spawn sh -c "ssh host001n < ./backup.py > /backup/dbbackup-$file-$date.txt"
expect "Enter passphrase for key '/root/.ssh/id_rsa':"
send "pass\r"
expect "Enter passphrase for key '/root/.ssh/id_rsa':"
send "pass\r"
expect "Enter passphrase for key '/root/.ssh/id_rsa':"
send "pass\r"
expect "Password:"
send "pass\r"
interact

done

After adding only one shebang here is the below error.

spawn sh -c cd /backup/
wrong # args: should be "for start test next command"
    while executing
"for ((i=0"
    (file "./backup.py" line 14)

Answer 1

Try this:

#!/usr/bin/env expect
set timeout 12
set date [timestamp -format "+%d-%B-%Y"]    ;# don't need to call out to date
cd /backup                                  ;# use the built-in cd command

# need to use Tcl syntax for the for loop, not shell syntax
for {set i 0} {$i < 8} {incr i} {
    spawn sh -c "ssh host001n < ./backup.py > /backup/dbbackup-$file-$date.txt"

    # more DRY
    expect {
        "Enter passphrase for key '/root/.ssh/id_rsa':" {
            send "pass\r"
            exp_continue
        }
        "Password:" {send "pass\r"}
        eof
    }
}