I used to get many questions about unattended FTP scripts.
On this page I will show some examples of unattended FTP download (or upload, the difference in script commands is small) scripts.
FTP [-v] [-d] [-i] [-n] [-g] [-s:filename] [-a] [-w:windowsize] [host] |
||
| where: | ||
| -v | Suppresses display of remote server responses. | |
| -n | Suppresses auto-login upon initial connection. | |
| -i | Turns off interactive prompting during multiple file transfers. | |
| -d | Enables debugging. | |
| -g | Disables filename globbing (see GLOB command). | |
| -s:filename | Specifies a text file containing FTP commands; the commands will automatically run after FTP starts. | |
| -a | Use any local interface when binding data connection. | |
| -A | Login as anonymous (available since Windows 2000). | |
| -w:buffersize | Overrides the default transfer buffer size of 4096. | |
| host | Specifies the host name or IP address of the remote host to connect to. | |
| Notes: | (1) | mget and mput commands take y/n/q for yes/no/quit. |
| (2) | Use Control-C to abort commands. |
The -s switch is the most valuable switch for batch files that take care of unattended downloads and uploads:
FTP -s:ftpscript.txt
On some operating systems redirection may do the same:
FTP < ftpscript.txt
However, unlike the -s switch its proper functioning cannot be guaranteed.
The following table shows the FTP commands available in Windows NT 4. The difference with other operating systems is marginal.
The actual commands available can be found by starting an FTP session and then typing a question mark at the FTP> prompt.
To get a short description af a particular command, type a question mark followed by that command: (user input shown in bold italics):
| C:\>ftp ftp> ? get get receive file ftp> ? mget mget get multiple files ftp> bye C:\> |
| FTP commands | |
|---|---|
| Command | Description |
! |
escape to the shell |
? |
print local help information |
append |
append to a file |
ascii |
set ascii transfer type |
bell |
beep when command completed |
binary |
set binary transfer type |
bye |
terminate ftp session and exit |
cd |
change remote working directory |
close |
terminate ftp session |
debug |
toggle debugging mode |
delete |
delete remote file |
dir |
list contents of remote directory |
disconnect |
terminate ftp session |
get |
receive file |
glob |
toggle metacharacter expansion of local file names |
hash |
toggle printing `#' for each buffer transferred |
help |
print local help information |
lcd |
change local working directory |
literal |
send arbitrary ftp command |
ls |
nlist contents of remote directory |
mdelete |
delete multiple files |
mdir |
list contents of multiple remote directories |
mget |
get multiple files |
mkdir |
make directory on the remote machine |
mls |
nlist contents of multiple remote directories |
mput |
send multiple files |
open |
connect to remote tftp |
prompt |
force interactive prompting on multiple commands |
put |
send one file |
pwd |
print working directory on remote machine |
quit |
terminate ftp session and exit |
quote |
send arbitrary ftp command |
recv |
receive file |
remotehelp |
get help from remote server |
rename |
rename file |
rmdir |
remove directory on the remote machine |
send |
send one file |
status |
show current status |
trace |
toggle packet tracing |
type |
set file transfer type |
user |
send new user information |
verbose |
toggle verbose mode |
Suppose an interactive FTP session looks like this (user input shown in bold italics):
| C:\>ftp ftp.myhost.net Connected to ftp.myhost.net. 220 *** FTP SERVER IS READY *** User (ftp.myhost.net:(none)): MyUserId 331 Password required for MyUserId. Password: **** 230- Welcome to the FTP site 230- Available space: 8 MB 230 User MyUserId logged in. ftp> cd files/pictures 250 CWD command successful. "files/pictures" is current directory. ftp> binary 200 Type set to B. ftp> prompt n Interactive mode Off. ftp> mget *.* 200 Type set to B. 200 Port command successful. 150 Opening data connection for firstfile.jpg. 226 File sent ok 649 bytes received in 0.00 seconds (649000.00 Kbytes/sec) 200 Port command successful. 150 Opening data connection for secondfile.gif. 226 File sent ok 467 bytes received in 0.00 seconds (467000.00 Kbytes/sec) ftp> bye 221 Goodbye. C:\> |
An FTP script for unattended file transfer would then look like this:
USER MyUserId MyPassword cd files/pictures binary prompt n mget *.*
Note that I left out the BYE (or QUIT) command, it isn't necessary to specify this command in unattended FTP scripts (though it doesn't do any harm either).
As you can see, using a script like this is a potential security risk: the password is stored in the script in a readable form.
As Tom Lavedas once pointed out in the alt.msdos.batch newsgroup, it is safer to create the script "on the fly" and delete it afterwards:
@ECHO OFF :: Check if the password was given IF "%1"=="" GOTO Syntax :: Create the temporary script file > script.ftp ECHO USER MyUserId >>script.ftp ECHO %1 >>script.ftp ECHO cd files/pictures >>script.ftp ECHO binary >>script.ftp ECHO prompt n >>script.ftp ECHO mget *.* :: Use the temporary script for unattended FTP :: Note: depending on your OS version you may have to add a '-n' switch FTP -v -s:script.ftp ftp.myhost.net :: For the paranoid: overwrite the temporary file before deleting it TYPE NUL >script.ftp DEL script.ftp GOTO End :Syntax ECHO Usage: %0 password :End
Sometimes it may be necessary to make the script completely unattended, without the user having to know the password, or even the user ID, but with the possibility to check for errors during transfer.
There are several ways to do this.
One is to redirect FTP's output to a log file and either display it to the user or use FIND to search the log file for any error messages.
Another way to do this, on the fly, is by displaying FTP's output on screen, in the mean time using FIND /V to hide the output you do not want the user to see (like the password and maybe even the USER command):
FTP -s:script.ftp ftp.myhost.net | FIND /V "USER" | FIND /V "%1"
It is important not to use FTP's -v switch in either case.
To create a semi interactive FTP script, you may need to split it into several smaller parts, like an unattended FTP script to read a list of remote files, the output of which is redirected to a temporary file, which in turn is used by a batch file to create a new unattended FTP script on the fly to download and/or delete some of these files.
Create these files by writing down every command and all screen output in an interactive FTP session, analyze this "log" thoroughly, and test, test, and test again!
And don't forget to log the results by redirecting the script's output to a log file. You may need it later for debugging purposes...
Instead of Windows' own native FTP command, you can choose from a multitude of "third party" alternatives.
I'll discuss three of those alternatives here: a command-line tool, a GUI-tool and VBScript with a third party ActiveX component.
| Note: | GNU WGET handles HTTP downloads just as easily. |
WGET is a port of the UNIX wget command.
WGET is perfect for anonymous FTP or HTTP downloads (sorry, no uploads), but it can be used for downloads requiring authentication too.
GNU WGET comes with help both in the (text mode) console and in Windows Help format.
The basic syntax for an FTP download doesn't get any simpler than this:
WGET ftp://ftp.mydomain.com/path/file.ext
for anonymous downloads, or:
WGET ftp://user:password@ftp.mydomain.com/path/file.ext
when authentication is required.
| Note: | This is not secure, as you would need to store your user ID and password in unencrypted format in the batch file. Besides that, the user ID and password will be logged together with the rest of the URL on all servers associated with the file transfer. Read the GNU WGET help file for more information on securing user IDs and passwords. |
WinSCP is a free open-source SFTP and FTP client with a command line/scripting interface as well as a GUI.
WinSCP can be used for uploads and downloads.
ScriptFTP is a tool to, you may have guessed, automate FTP file transfers.
It supports plain FTP, FTPS and SFTP protocols.
Commands to e-mail and/or log results are available.
All commands can be run on the command line or from a script.
Scripts can be encrypted, or converted online to self-contained executables.
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The per-unit (pu) system simplifies this by normalizing all network parameters (voltages, currents, impedances, and powers) to a common base. This eliminates the need to refer impedances across transformer windings, ensuring that the per-unit impedance remains identical whether viewed from the primary or secondary side. Impedance and Admittance Matrices For a network with
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