| <!-- | |
| Copyright (C) Daniel Stenberg, <[email protected]>, et al. | |
| SPDX-License-Identifier: curl | |
| --> | |
| # Features -- what curl can do | |
| ## curl tool | |
| - config file support | |
| - multiple URLs in a single command line | |
| - range "globbing" support: [0-13], {one,two,three} | |
| - multiple file upload on a single command line | |
| - redirect stderr | |
| - parallel transfers | |
| ## libcurl | |
| - URL RFC 3986 syntax | |
| - custom maximum download time | |
| - custom lowest download speed acceptable | |
| - custom output result after completion | |
| - guesses protocol from hostname unless specified | |
| - supports .netrc | |
| - progress bar with time statistics while downloading | |
| - standard proxy environment variables support | |
| - have run on 101 operating systems and 28 CPU architectures | |
| - selectable network interface for outgoing traffic | |
| - IPv6 support on Unix and Windows | |
| - happy eyeballs dual-stack IPv4 + IPv6 connects | |
| - persistent connections | |
| - SOCKS 4 + 5 support, with or without local name resolving | |
| - *pre-proxy* support, for *proxy chaining* | |
| - supports username and password in proxy environment variables | |
| - operations through HTTP proxy "tunnel" (using CONNECT) | |
| - replaceable memory functions (malloc, free, realloc, etc) | |
| - asynchronous name resolving | |
| - both a push and a pull style interface | |
| - international domain names (IDN) | |
| - transfer rate limiting | |
| - stable API and ABI | |
| - TCP keep alive | |
| - TCP Fast Open | |
| - DNS cache (that can be shared between transfers) | |
| - non-blocking single-threaded parallel transfers | |
| - Unix domain sockets to server or proxy | |
| - DNS-over-HTTPS | |
| - uses non-blocking name resolves | |
| - selectable name resolver backend | |
| ## URL API | |
| - parses RFC 3986 URLs | |
| - generates URLs from individual components | |
| - manages "redirects" | |
| ## Header API | |
| - easy access to HTTP response headers, from all contexts | |
| - named headers | |
| - iterate over headers | |
| ## TLS | |
| - selectable TLS backend(s) | |
| - TLS False Start | |
| - TLS version control | |
| - TLS session resumption | |
| - key pinning | |
| - mutual authentication | |
| - Use dedicated CA cert bundle | |
| - Use OS-provided CA store | |
| - separate TLS options for HTTPS proxy | |
| ## HTTP | |
| - HTTP/0.9 responses are optionally accepted | |
| - HTTP/1.0 | |
| - HTTP/1.1 | |
| - HTTP/2, including multiplexing and server push | |
| - GET | |
| - PUT | |
| - HEAD | |
| - POST | |
| - multipart formpost (RFC 1867-style) | |
| - authentication: Basic, Digest, NTLM (9) and Negotiate (SPNEGO) | |
| to server and proxy | |
| - resume transfers | |
| - follow redirects | |
| - maximum amount of redirects to follow | |
| - custom HTTP request | |
| - cookie get/send fully parsed | |
| - reads/writes the Netscape cookie file format | |
| - custom headers (replace/remove internally generated headers) | |
| - custom user-agent string | |
| - custom referrer string | |
| - range | |
| - proxy authentication | |
| - time conditions | |
| - via HTTP proxy, HTTPS proxy or SOCKS proxy | |
| - HTTP/2 or HTTP/1.1 to HTTPS proxy | |
| - retrieve file modification date | |
| - Content-Encoding support for deflate, gzip, brotli and zstd | |
| - "Transfer-Encoding: chunked" support in uploads | |
| - HSTS | |
| - alt-svc | |
| - ETags | |
| - HTTP/1.1 trailers, both sending and getting | |
| ## HTTPS | |
| - HTTP/3 | |
| - using client certificates | |
| - verify server certificate | |
| - via HTTP proxy, HTTPS proxy or SOCKS proxy | |
| - select desired encryption | |
| - select usage of a specific TLS version | |
| - ECH | |
| ## FTP | |
| - download | |
| - authentication | |
| - Kerberos 5 | |
| - active/passive using PORT, EPRT, PASV or EPSV | |
| - single file size information (compare to HTTP HEAD) | |
| - 'type=' URL support | |
| - directory listing | |
| - directory listing names-only | |
| - upload | |
| - upload append | |
| - upload via http-proxy as HTTP PUT | |
| - download resume | |
| - upload resume | |
| - custom ftp commands (before and/or after the transfer) | |
| - simple "range" support | |
| - via HTTP proxy, HTTPS proxy or SOCKS proxy | |
| - all operations can be tunneled through proxy | |
| - customizable to retrieve file modification date | |
| - no directory depth limit | |
| ## FTPS | |
| - implicit `ftps://` support that use SSL on both connections | |
| - explicit "AUTH TLS" and "AUTH SSL" usage to "upgrade" plain `ftp://` | |
| connection to use SSL for both or one of the connections | |
| ## SSH (both SCP and SFTP) | |
| - selectable SSH backend | |
| - known hosts support | |
| - public key fingerprinting | |
| - both password and public key auth | |
| ## SFTP | |
| - both password and public key auth | |
| - with custom commands sent before/after the transfer | |
| - directory listing | |
| ## TFTP | |
| - download | |
| - upload | |
| ## TELNET | |
| - connection negotiation | |
| - custom telnet options | |
| - stdin/stdout I/O | |
| ## LDAP | |
| - full LDAP URL support | |
| ## DICT | |
| - extended DICT URL support | |
| ## FILE | |
| - URL support | |
| - upload | |
| - resume | |
| ## SMB | |
| - SMBv1 over TCP and SSL | |
| - download | |
| - upload | |
| - authentication with NTLMv1 | |
| ## SMTP | |
| - authentication: Plain, Login, CRAM-MD5, Digest-MD5, NTLM, Kerberos 5 and | |
| External | |
| - send emails | |
| - mail from support | |
| - mail size support | |
| - mail auth support for trusted server-to-server relaying | |
| - multiple recipients | |
| - via http-proxy | |
| ## SMTPS | |
| - implicit `smtps://` support | |
| - explicit "STARTTLS" usage to "upgrade" plain `smtp://` connections to use SSL | |
| - via http-proxy | |
| ## POP3 | |
| - authentication: Clear Text, APOP and SASL | |
| - SASL based authentication: Plain, Login, CRAM-MD5, Digest-MD5, NTLM, | |
| Kerberos 5 and External | |
| - list emails | |
| - retrieve emails | |
| - enhanced command support for: CAPA, DELE, TOP, STAT, UIDL and NOOP via | |
| custom requests | |
| - via http-proxy | |
| ## POP3S | |
| - implicit `pop3s://` support | |
| - explicit `STLS` usage to "upgrade" plain `pop3://` connections to use SSL | |
| - via http-proxy | |
| ## IMAP | |
| - authentication: Clear Text and SASL | |
| - SASL based authentication: Plain, Login, CRAM-MD5, Digest-MD5, NTLM, | |
| Kerberos 5 and External | |
| - list the folders of a mailbox | |
| - select a mailbox with support for verifying the `UIDVALIDITY` | |
| - fetch emails with support for specifying the UID and SECTION | |
| - upload emails via the append command | |
| - enhanced command support for: EXAMINE, CREATE, DELETE, RENAME, STATUS, | |
| STORE, COPY and UID via custom requests | |
| - via http-proxy | |
| ## IMAPS | |
| - implicit `imaps://` support | |
| - explicit "STARTTLS" usage to "upgrade" plain `imap://` connections to use SSL | |
| - via http-proxy | |
| ## MQTT | |
| - Subscribe to and publish topics using URL scheme `mqtt://broker/topic` | |