Stuff about command-line ftp

Thu, 12 Jan 2017 12:07:43 -0500

To connect to a machine with ip MACHINE, you simply need to enter the below at command-line:

ftp MACHINE

See below for a list of commands you would typically use once you ftp to a machine.

Basic FTP Commands #

Command	Description
`?` or `help`	Get help on FTP commands
`bye` or `quit`	Exit the FTP session
`binary`	Set the mode of file transfer to binary
	(Provides less chance of transmission error)
`cd`, `ls`, `mkdir`, `pwd`, `rmdir`	Unix operations on remote machine
`delete`	Unix `rm` operation on remote machine
`lcd`	Unix `cd` operation on local machine
`put` FILE	Copy 1 file from local to remote
`mput` FILES (ex: `mput *`)	Copy multiple files from local to remote
`get` FILE	Copy 1 file from remote to local
`mget` FILES (ex: `mget*`)	Copy multiple files from remote to local

Automating FTP logins for specific IPs #

If you find yourself logging into a specific MACHINE too frequently, and if you want to save yourself from having to enter the username and password each time, you can save those credentials to your ~/.netrc file. See the example at the end of this post.

If that file does not exist, then create it, and remember to set its permission to 600.

touch ~/.netrc
chmod 600 ~/.netrc

If the permissions are not set so, you will get this ftp error:

Error - .netrc file not correct mode.
Remove password or correct mode.

Ignore the credentials in `.netrc` #

But at times, you might need to manually log into a machine with a different set of credentials than the one saved in the ~/.netrc. To do so, run ftp with the -n option. And then use the quote USER and quote PASS commands to pass in the username and password.

> ftp -n <machine>
ftp> quote USER <username>
ftp> quote PASS <password>

Commenting out stuff in `.netrc` #

Unfortunately, .netrc does not seem to have a comment syntax. But this hack works ..

Using the # character quickly followed by an FTP command foo (no space, ex: #foo) is one way to “comment out” lines with valid .netrc keywords.

You cannot have such ‘comments’ after valid .netrc keywords are used.

So if you need to comment out a set of logins and passwords, do that before the first valid set of uncommented login credentials. See below for an example of that.

An Example `~/.netrc` #

#machine foo.bar.com
#login username1
#password pAsSw0rd1
machine foo.bar.com
login username2
password pAsSw0rd2

References #

Basic FTP Commands - Colorado State Univerity
Use configuration file for ftp with auto login enabled upon initial connection - unix.stackexchange
man ftp, man netrc

ftp on A Scripter's Notes