How can I upload (FTP) files to server in a Bash script?

Below are two answers. First is a suggestion to use a more secure/flexible solution like ssh/scp/sftp. Second is an explanation of how to run ftp in batch mode.

A secure solution:

You really should use SSH/SCP/SFTP for this rather than FTP. SSH/SCP have the benefits of being more secure and working with public/private keys which allows it to run without a username or password.

You can send a single file:

scp <file to upload> <username>@<hostname>:<destination path>

Or a whole directory:

scp -r <directory to upload> <username>@<hostname>:<destination path>

For more details on setting up keys and moving files to the server with RSYNC, which is useful if you have a lot of files to move, or if you sometimes get just one new file among a set of random files, take a look at:

http://troy.jdmz.net/rsync/index.html

You can also execute a single command after sshing into a server:

From man ssh

ssh [...snipped...] hostname [command] If command is specified, it is executed on the remote host instead of a login shell.

So, an example command is:

ssh [email protected] bunzip file_just_sent.bz2

If you can use SFTP with keys to gain the benefit of a secured connection, there are two tricks I've used to execute commands.

First, you can pass commands using echo and pipe

echo "put files*.xml" | sftp -p -i ~/.ssh/key_name [email protected]

You can also use a batchfile with the -b parameter:

sftp -b batchfile.txt ~/.ssh/key_name [email protected]

An FTP solution, if you really need it:

If you understand that FTP is insecure and more limited and you really really want to script it...

There's a great article on this at http://www.stratigery.com/scripting.ftp.html

#!/bin/sh
HOST='ftp.example.com'
USER='yourid'
PASSWD='yourpw'
FILE='file.txt'

ftp -n $HOST <<END_SCRIPT
quote USER $USER
quote PASS $PASSWD
binary
put $FILE
quit
END_SCRIPT
exit 0

The -n to ftp ensures that the command won't try to get the password from the current terminal. The other fancy part is the use of a heredoc: the <<END_SCRIPT starts the heredoc and then that exact same END_SCRIPT on the beginning of the line by itself ends the heredoc. The binary command will set it to binary mode which helps if you are transferring something other than a text file.

You can use a heredoc to do this, e.g.

ftp -n $Server <<End-Of-Session
# -n option disables auto-logon

user anonymous "$Password"
binary
cd $Directory
put "$Filename.lsm"
put "$Filename.tar.gz"
bye
End-Of-Session

so the ftp process is fed on standard input with everything up to End-Of-Session. It is a useful tip for spawning any process, not just ftp! Note that this saves spawning a separate process (echo, cat, etc.). It is not a major resource saving, but it is worth bearing in mind.

The ftp command isn't designed for scripts, so controlling it is awkward, and getting its exit status is even more awkward.

Curl is made to be scriptable, and also has the merit that you can easily switch to other protocols later by just modifying the URL. If you put your FTP credentials in your .netrc, you can simply do:

# Download file
curl --netrc --remote-name ftp://ftp.example.com/file.bin
# Upload file
curl --netrc --upload-file file.bin ftp://ftp.example.com/

If you must, you can specify username and password directly on the command line using --user username:password instead of --netrc.