Shell Programming and Scripting

cd /your_path
while true; do
        if [ -f your_file.txt ]; then
                break
        else
                sleep 60
                get_data_files
        fi
done
get_data_files()
{
echo "Copying your_file.txt file from ${WINDIR}"
ftp -in $ftp_server << EOF > ~/log.txt 2>&1
user $user_name $pass_word
cd $dir
get your_file.txt
bye
}

get_data_files()
{
echo "Copying your_file.txt file from ${WINDIR}"
ftp -in $ftp_server << EOF > ~/log.txt 2>&1
user $user_name $pass_word
cd $dir
get your_file.txt
bye
EOF
}