http://www.overclockers.com/forums/showthread.php?t=671900

Push script with sftp

#!/bin/bash

#Sets the IP address of the ftp server
SERVER=192.168.56.50

FOLDER=/root/sftp

#this grabs the list of files available on the server
FILE_LIST=`sftp $SERVER << EOF
cd sftp
ls
quit
EOF`
echo $FILE_LIST > temp_file_list

#this is used to remove everything except xml files
for DOWNLOAD_FILE in `cat temp_file_list`
do
        echo $DOWNLOAD_FILE |grep .xml >> download
done

#ensure that the files are sorted properly
sort download > download_list

#get the local list
ls |grep .xml | sort > local_list

# checks to see which files are on the server that are not
# on the local machine
DIFF=`diff local_list download_list | cut -c3- |grep .xml`

#check to see if each file in the server's list exists on the local maching
if [ `echo $DIFF` =="" ]

# If there are no differences in the folder assume there is nothing
# new to transfer
then
echo No New Files to transfer
else
for SERVER_FILE in $DIFF
        do
                        #if the file does not exist, grab it
                        sftp $SERVER << EOF
                        cd sftp
                        put $SERVER_FILE
                exit
fi 2>/dev/null

#remove the temporary file lists
rm local_list
rm temp_file_list
rm download
rm download_list