* Log onto the FTP site.
FTPLOGON 'ftp.robo-ftp.com' /user=anonymous

* Change the current directory on the server
FTPCD 'outgoing'

* Check to see if there is already a pre-existing SNAPSHOT database
* If so, we can skip the "do_snapshot" routine, which creates that database
IFFILE "ftpsnapshot_test.sql" GOTO do_diff

:do_snapshot
* Take a snapshot of the current directory
* This isn't necessary with every run
FTPSNAPSHOT "" "ftpsnapshot_test.sql"

* Check to see if there was an error in creating the snapshot.
IFERROR GOTO error_in_snapshot

:do_diff
* Check the site for changes.
FTPDIFF "*" "ftpsnapshot_test.sql"

* Check for an error in the DIFF command
IFERROR GOTO error_in_diff

* If there are differences, then download files
IFNUM> %ftpdifffiles 00 GOTO do_getdiff

* Otherwise, finish the script
GOTO done

:do_getdiff
* First, do a rewind to make sure you are looking at the first difference
FTPDIFFREWIND 

:download_files
* Check the next difference
FTPGETDIFF "ftpsnapshot_test.sql"

* An EOF error indicates that all files have been downloaded; exit the loop
IFERROR= $ERROR_READ_EOF GOTO download_complete

* Any other error indicates that something went wrong when checking the 
* database, so we need to check for that error
IFERROR GOTO error_in_getdiff

* if the difference is $DIFF_FILE_NOT_FOUND, do not delete the file, skip this 
* file and go back to the top of the loop
IFNUM= %ftpdifffileid 5001 GOTO download_files

* the other difference types indicate that the site file is new or has changed, 
* so let's download it
RCVFILE %ftpdifffilename

* check for an error when downloading
IFERROR GOTO error_in_download

* move on to the next difference
GOTO download_files

:download_complete
* do another diff, to see if anything changed while we were downloading files
* in most cases, there will be no more differences, and the do_diff procedure 
* will simply exit to the "done" label.
GOTO do_diff

:error_in_download
* You would normally place any error handling in this section.  For the sake 
* of brevity, we have omitted any specific error handling.
* You script should respond to download errors.  Download errors are typically 
* caused by networking issues, or file read/write permissions
* Common error-handling includes:
*   logging off the server and logging back on, then trying to download again
*   writing a test file to the database location, to check for file read/write errors
*   reporting the error to an administrator, usually via email
*   logging off the server and ending script execution

:error_in_snapshot
* You would normally place any error handling in this section.  For the sake 
* of brevity, we have omitted any specific error handling.
* You script should respond to FTPSNAPSHOT errors.  Since FTPSNAPSHOT is creating 
* a database of information from the server, errors can come either
* from an error in getting server information or in writing that information to disk.

:error_in_diff
* You would normally place any error handling in this section.  For the sake 
* of brevity, we have omitted any specific error handling.
* You script should respond to FTPDIFF errors.  Since FTPDIFF is comparing a 
* database of information to the current conditions in the server, the most
* frequent cause for an error hear is either a problem in the database file, 
* or a problem getting information to the server.

:error_in_getdiff
* You would normally place any error handling in this section.  For the sake 
* of brevity, we have omitted any specific error handling.
* You script should respond to FTPGETDIFF errors.  FTPGETDIFF errors indicate 
* a problem retrieving information from the FTPDIFF database

:done
FTPLOGOFF
* Bye