Bash+Expect script not running properly in crontab

Question

I have a bash script that is supposed to run periodically. the script should connect to a remote SFTP server and get a file from there. Since this is a SFTP server I had to use expect with the bash script. the script runs well when I run it manually but fails when running via crontab. the problematic function is the get_JSON_file() please advise...

this is the code:

#!/bin/bash

export xxxxx
export xxxxx
export PATH=xxxxx

check_if_file_is_open(){
while :
do
    if ! [[ `lsof | grep file.txt` ]]
    then
        break
    fi
    sleep 1
done
}


get_JSON_file(){
/usr/bin/expect -f <(cat << EOF
spawn sftp -P port user@ip
expect "Password:"
send "password\r"
expect "$ "
send "get path/to/file/file.json\r"
send "exit\r"
interact
EOF
)
}


get_JSON_file
check_if_file_is_open
cp file.txt /path/to/destination/folder

Answer 1

To run a function within a shell script, no parentheses should be used.

Your code then becomes:

#!/bin/bash

export xxxxx
export xxxxx
export PATH=xxxxx

function check_if_file_is_open(){
while :
do
    if ! [[ `lsof | grep file.txt` ]]
    then
        break
    fi
    sleep 1
done
}


function get_JSON_file(){
/usr/bin/expect -f <(cat << EOF
spawn sftp -P port user@ip
expect "Password:"
send "password\r"
expect "$ "
send "get path/to/file/file.json\r"
send "exit\r"
interact
EOF
)
}


get_JSON_file
check_if_file_is_open
cp file.txt /path/to/destination/folder