curl/docs/cmdline-opts/_PROTOCOLS.md
Daniel Stenberg ceae02db04
rtmp: drop support
- librtmp has no test cases, makes no proper releases and has not had a
  single commit within the last year

- librtmp parses the URL itself and requires non-compliant URLs for this

- we have no RTMP tests

- RTMP was used by 2.2% of curl users (self-identified in the 2025
  survey)

Closes #20673
2026-03-21 14:56:06 +01:00

50 lines
1.8 KiB
Markdown

<!-- Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. -->
<!-- SPDX-License-Identifier: curl -->
# PROTOCOLS
curl supports numerous protocols, or put in URL terms: schemes. Your
particular build may not support them all.
## DICT
Lets you lookup words using online dictionaries.
## FILE
Read or write local files. curl does not support accessing file:// URL
remotely, but when running on Microsoft Windows using the native UNC approach
works. Only absolute paths.
## FTP(S)
curl supports the File Transfer Protocol with a lot of tweaks and levers. With
or without using TLS.
## GOPHER(S)
Retrieve files.
## HTTP(S)
curl supports HTTP with numerous options and variations. It can speak HTTP
version 0.9, 1.0, 1.1, 2 and 3 depending on build options and the correct
command line options.
## IMAP(S)
Using the mail reading protocol, curl can download emails for you. With or
without using TLS.
## LDAP(S)
curl can do directory lookups for you, with or without TLS.
## MQTT
curl supports MQTT version 3. Downloading over MQTT equals subscribing to a
topic while uploading/posting equals publishing on a topic. MQTT over TLS is not
supported (yet).
## POP3(S)
Downloading from a pop3 server means getting an email. With or without using
TLS.
## RTSP
curl supports RTSP 1.0 downloads.
## SCP
curl supports SSH version 2 scp transfers.
## SFTP
curl supports SFTP (draft 5) done over SSH version 2.
## SMB(S)
curl supports SMB version 1 for upload and download.
## SMTP(S)
Uploading contents to an SMTP server means sending an email. With or without
TLS.
## TELNET
Fetching a telnet URL starts an interactive session where it sends what it
reads on stdin and outputs what the server sends it.
## TFTP
curl can do TFTP downloads and uploads.
## WS(S)
WebSocket done over HTTP/1. WSS implies that it works over HTTPS.