List of 28 Protocols supported by cURL with Examples

cURL supports an extensive list of Protocols,

Let's take a look at some of the examples with each one of them,

DICT

Using DICT protocol you fetch definitions and details of words using online dictionaries.

Example:

$ curl dict://dict.org/d:soccer
220 dict.dict.org dictd 1.12.1/rf on Linux 4.19.0-10-amd64 <auth.mime> <156867369.27138.1670825746@dict.dict.org>
250 ok
150 1 definitions retrieved
151 "soccer" wn "WordNet (r) 3.0 (2006)"
soccer
    n 1: a football game in which two teams of 11 players try to
         kick or head a ball into the opponents' goal [syn:
         {soccer}, {association football}]
.
250 ok [d/m/c = 1/0/32; 0.000r 0.000u 0.000s]
221 bye [d/m/c = 0/0/0; 0.000r 0.000u 0.000s]

FILE

Using the FILE protocol with cURL, you can get a file from your local system. Note this is not a network protocol.

Example: FILE Protocol on macOS/Linux

% curl file:///Users/code2care/Desktop/file.html
Hello World!

Example: FILE Protocol on Windows

> curl file://c:/users/code2care/desktop/file.html
Hello World!

FTP

The File Transfer Protocol, to download and upload files on an FTP Server,

Example:

$ curl ftp://ftp.code2care.org/2023/

FTPS

FTPS Protocol is an extension to the File Transfer Protocol (FTP), it adds support for the Transport Layer Security (TLS)

Example:

$ curl ftps://ftps.code2care.org/2023/

GOPHER

GOPHER is a distributing, searching, and retrieving documents over the Internet Protocol.

Example:

$ curl gopher://gopher.code2care.org

GOPHERS

GOPHERS is a secured Gopher using TLS.

Example:

$ curl gophers://gophers.code2care.org

HTTP

HTTP is what we are all familiar with: Hypertext Transfer Protocol,

Example:

$ curl http://code2care.org

HTTPS

HTTPS is secured HTTP using SSL/TLS,

Example:

$ curl https://code2care.org

IMAP

IMAP: Internet Message Access Protocol is used for reading email.

Example:

$ curl imap://imap.code2care.org/mail-server -u user:password

IMAPS

IMAPS is secured IMAP using SSL/TLS.

Example:

$ curl imaps://imaps.code2care.org/mail-server -u user:password

LDAP

LDAP is a Lightweight Directory Access Protocol used for accessing and maintaining distributed directory information.

Example:

curl "ldap://ldap.code2care.org:1200/dc=code2care,dc=org?dir?sub?cn=code2care" -u "cn=admin"
Enter host password for user 'cn=admin':
DN: uid=code2careorg,ou=People,dc=code2care,dc=org
homephone: +1 XX XX XXXX

LDAPS

LDAPS is secured LDAP using SSL/TLS.

Example:

curl "ldaps://ldaps.code2care.org:1200/dc=code2care,dc=org?dir?sub?cn=code2care" -u "cn=admin"
Enter host password for user 'cn=admin':
DN: uid=code2careorg,ou=People,dc=code2care,dc=org
homephone: +1 XX XX XXXX

MQTT

MQTT: Message Queuing Telemetry Transport is a pub-sub-based protocol, widely used in IoT systems.

$ curl mqtt://cod2care.org/sensor/humidity

Publish Example:

curl -d 22 mqtt://codde2care.org/sensor/status

POP3

POP3: Post Office Protocol version 3 is a protocol that is used for retrieving email from a mail server.

Example:

$ curl pop3://mail.code2care.org

POP3S

POP3S is secured using SSL/TLS.

Example:

$ curl pop3s://mail.code2care.org

RTMP

RTMP: Real-Time Messaging Protocol is a protocol used for streaming audio, video, and data.

Example:

$ curl rtmp://rtmp.code2care.org/video/sample.mp4

RTMPS

RTMPS is secured using SSL/TLS.

Example:

$ curl rtmps://rtmps.code2care.org/video/visuals.mp4

RTSP

RTSP: Real Time Streaming Protocol is a network protocol for controlling streaming media servers.

Example:

$ curl rtsp://rtsp.code2care.org/video/apple.mp4

SCP

SCP: Secure Copy protocol is used to copy files to and from a remote SSH server.

Example:

$ curl scp://scp.code2care.org/2023.csv -u user

SFTP

SFTP: SSH File Transfer Protocol is used to access, transfer, manage remote files over a reliable data stream.

Example:

$ curl sftp://sftp.code2care.org/2023.csv -u user

SMB

SMB: Server Message Block protocol an application-layer network protocol used for providing shared access to files, printers, and serial ports.

Example:

$ curl -u "code2care\user:password" smb://2023/JAN/01

SMBS

Secured SMB using SSL/TLS.

Example:

$ curl -u "code2care\user:password" smbs://2023/JAN/01

SMTP

SMTP: Simple Mail Transfer Protocol is used for email transmission.

Example:

$ curl sftp://sftp.code2care.org/2023_file.txt -u user

SMTPS

It is a secured SMTP using SSL/TLS.

Example:

$ curl sftps://sftps.code2care.org/2023_file.txt -u user

TELNET

TELNET is an Application Layer Protocol. It is used to provide a bidirectional interactive text-oriented communication facility using a virtual terminal connection.

Example:

$ curl telnet://code2care.org

TFTP

TFTP: Trivial File Transfer Protocol is used for file transfers over UDP to get a file from or put a file onto a remote host

Download Example:

$ curl -O tftp://code2care-server/conf.txt

Upload Example:

$ curl -T conf.txt tftp://cod2care-server/

WS

WS: WebSocket is a bidirectional TCP-like protocol over an HTTP request.

Example:

$ curl ws://code2care.org

WSS

WS: WebSocket is a bidirectional TCP-like protocol over an HTTP request.

Example:

$ curl wss://code2care.org

Facing issues? Have Questions? Post them here! I am happy to answer!

Author Info:

Rakesh is a seasoned developer with over 10 years of experience in web and app development, and a deep knowledge of operating systems. Author of insightful How-To articles for Code2care.

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