This project implements an FTP client which supports the following commands:
ls <URL>Prints out the directory listing from the FTP server at the given URLmkdir <URL>Creates a new directory on the FTP server at the given URLrm <URL>Deletes the file on the FTP server at the given URLrmdir <URL>Delete the directory on the FTP server at the given URLcp <ARG1> <ARG2>Copy the file given by ARG1 to the file given by ARG2. If ARG1 is a local file, then ARG2 must be a URL, and vice-versa.mv <ARG1> <ARG2>Move the file given by ARG1 to the file given by ARG2. If ARG1 is a local file, then ARG2 must be a URL, and vice-versa.
Remote files and directories should be specified in the following URL format:
ftp://[USER[:PASSWORD]@]HOST[:PORT]/PATH
Where USER and PASSWORD are the username and password to access the FTP server, HOST is the domain name or IP address of the FTP server, PORT is the remote port for the FTP server, and PATH is the path to a file or directory.
HOST and PATH are the minimum required fields in the URL, all other fields are optional. The default USER is 'anonymous' with no PASSWORD. The default PORT is 21.
I implemented this client by first using the Python argparse library to support the
necessary program arguments. After parsing arguments I established connection to the
server via the control channel and added support for sending commands and receiving
responses. I then divided the main method into cases based on the operation being used.
Note that this program uses chained if/elif statements because match is not supported
by the submission server. I implemented general functionalities such as receiving data
as bytes and opening data channels as needed while creating functionality for
the operations.
One challenging aspect of this project was opening and correctly using data channels.
It was particularly challenging to support file download because it required determining
when the data channel was done sending the file bytes, which was different from receiving
messages from the control channel (which always end in \r\n).
I tested my code by creating files locally, and performing the various operations on files and directories using the FTP client. This included creating and removing directories, copying files to the server, deleting files, and copying files back to my local environment. I used print statements and the list command to ensure proper communication between the client and server throughout the program execution.