How to upload one file by FTP from command line?

Here is one approach:

$ ftp -n <<EOF
open ftp.example.com
user user secret
put my-local-file.txt
EOF

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Alternatively, create (or edit) the ~/.netrc file in the home dir of the user that will run the ftp command, give it appropriate perms (chmod 0600 ~/.netrc), and add the following:

# ~/.netrc
machine ftp.example.com
login user
password secret

Then omit the login information, as in:

$ echo put my-local-file.txt | ftp ftp.example.com

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Also, here's how you might do the same thing using curl:

$ curl -T my-local-file.txt ftp://ftp.example.com --user user:secret

I can recommend ftp-upload. It's a neat little tool that you can install under ubuntu through sudo apt-get install ftp-upload.

Usage example:

ftp-upload -h {HOST} -u {USERNAME} --password {PASSWORD} -d {SERVER_DIRECTORY} {FILE_TO_UPLOAD}

You need to fix the URL given in your statement. You received the error because the URL was incomplete - it was missing the name of the object you are uploading. Once you add the filename after 'example.com' as I have done below, you will see the single command does indeed work as you intended.

Try this:

ftp -u ftp://user:[email protected]/my-local-file.txt my-local-file.txt