CIS120Linux Fundementals

wget, ftp and sftp Commands

The wget, ftp, and sftp commands are essential tools for transferring files between computers in Linux. wget is a non-interactive network downloader, while ftp and sftp are used for interactive file transfers, with sftp being the preferred and more secure option.

The wget Command

The wget command is used for downloading files from the web. It supports HTTP, HTTPS, and FTP protocols and can download files non-interactively, making it ideal for automated downloads.

Basic usage of wget:

wget [options] [URL]

Commonly Used wget Options:

Option	Description
-O	Write output to a file instead of standard output
-c	Resume a partially downloaded file
-q	Quiet mode (no output)
-r	Recursive download
-l	Set the maximum depth for recursive downloads
--limit-rate	Limit the download speed

To download a file using wget:

wget http://example.com/file.txt

Output:

--2024-07-10 10:00:00--  http://example.com/file.txt
Resolving example.com (example.com)... 93.184.216.34
Connecting to example.com (example.com)|93.184.216.34|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 1234 (1.2K) [text/plain]
Saving to: 'file.txt'

file.txt          100%[===================>]   1.21K  --.-KB/s    in 0s      

2024-07-10 10:00:01 (234 MB/s) - ‘file.txt’ saved [1234/1234]

The ftp Command

The ftp (File Transfer Protocol) command is used to transfer files between a client and a server. It is an older protocol that is less secure compared to sftp. ftp transfers data in plaintext, making it vulnerable to interception and attacks. Due to its security limitations, sftp is now the preferred method for file transfers.

The sftp Command

The sftp (Secure File Transfer Protocol) command is a secure version of ftp that uses SSH (Secure Shell) to encrypt the data being transferred. It is preferred over ftp due to its enhanced security features.

Basic usage of sftp:

sftp [user@]hostname

Commonly Used sftp Options:

Option	Description
-b	Batch mode reads a series of commands from a file
-C	Enable compression
-P	Specify an alternate port
-i	Specify an identity file (private key)
-q	Quiet mode
-v	Verbose mode

Examples and Output Explanations

To connect to an SFTP server:

sftp user@ftp.example.com

Output:

Connecting to ftp.example.com...
user@ftp.example.com's password: 
sftp>

To list files on the remote server:

ls

Output:

files
file.txt

To list files on the local machine:

lls

Output:

Desktop  Documents  Downloads  file.txt  Pictures

To change directories on the remote server:

cd /path/to/remote/directory

Output:

sftp> cd /path/to/remote/directory

To change directories on the local machine:

lcd /path/to/local/directory

Output:

sftp> lcd /path/to/local/directory

To download a file from the remote server:

get file.txt

Output:

Fetching /home/user/file.txt to file.txt
/home/user/file.txt                             100% 1234     1.2KB/s   00:00

To upload a file to the remote server:

put localfile.txt remotefile.txt

Output:

Uploading localfile.txt to /home/user/remotefile.txt
localfile.txt                                   100% 1234     1.2KB/s   00:00

To download multiple files:

mget *.txt

To upload multiple files:

mput *.txt

Differences Between ftp and sftp

The key difference between ftp and sftp is security. ftp transfers data in plaintext, which makes it vulnerable to interception and attacks. In contrast, sftp uses SSH to encrypt the data being transferred, providing a secure channel that protects the data from being intercepted or tampered with.

Due to its security advantages, sftp is now preferred over ftp for file transfers.

Summary

The wget, ftp, and sftp commands are powerful tools for downloading and transferring files in Linux. wget is used for non-interactive downloads, while ftp and sftp are used for interactive file transfers, with sftp being the preferred option due to its enhanced security features. By mastering these commands and understanding their options, you can efficiently manage file transfers in the Linux environment.