A command line tool and library for transferring data with URL syntax, supporting DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS. libcurl offers a myriad of powerful features
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Stefan Eissing 24b36fdd15
ratelimit: redesign
Description of how this works in `docs/internal/RATELIMITS.ms`.

Notable implementation changes:
- KEEP_SEND_PAUSE/KEEP_SEND_HOLD and KEEP_RECV_PAUSE/KEEP_RECV_HOLD
  no longer exist. Pausing is down via blocked the new rlimits.
- KEEP_SEND_TIMED no longer exists. Pausing "100-continue" transfers
  is done in the new `Curl_http_perform_pollset()` method.
- HTTP/2 rate limiting implemented via window updates. When
  transfer initiaiting connection has a ratelimit, adjust the
  initial window size
- HTTP/3 ngtcp2 rate limitin implemnented via ack updates
- HTTP/3 quiche does not seem to support this via its API
- the default progress-meter has been improved for accuracy
  in "current speed" results.

pytest speed tests have been improved.

Closes #19384
2025-11-24 23:34:05 +01:00
.circleci runtests: detect bad libssh differently for test 1459 (fixing CircleCI libssh job) 2025-11-16 23:28:44 +01:00
.github GHA: update dependency ngtcp2/nghttp3 to v1.13.1 2025-11-24 17:41:50 +01:00
CMake cmake: add support for libbacktrace, fix two build issues 2025-11-24 14:29:29 +01:00
docs ratelimit: redesign 2025-11-24 23:34:05 +01:00
include build: add build-level CURL_DISABLE_TYPECHECK options 2025-11-21 13:48:35 +01:00
lib ratelimit: redesign 2025-11-24 23:34:05 +01:00
LICENSES krb5: drop support for Kerberos FTP 2025-09-20 23:58:28 +02:00
m4 badwords: add more contractions, fix fallouts 2025-11-17 19:29:15 +01:00
packages badwords: add more contractions, fix fallouts 2025-11-17 19:29:15 +01:00
plan9 tidy-up: LibreSSL Git repository URLs and local CI builds 2025-10-01 12:55:20 +02:00
projects projects/README.md: Markdown fixes 2025-11-17 15:09:09 +01:00
scripts curlx: replace mbstowcs/wcstombs with _s counterparts (Windows) 2025-11-21 16:45:42 +01:00
src tool_writeout: bail out proper on OOM 2025-11-24 13:32:51 +01:00
tests ratelimit: redesign 2025-11-24 23:34:05 +01:00
.dir-locals.el copyright: update all copyright lines and remove year ranges 2023-01-03 09:19:21 +01:00
.editorconfig .editorconfig: add 2025-09-02 08:36:40 +02:00
.git-blame-ignore-revs copyright: update all copyright lines and remove year ranges 2023-01-03 09:19:21 +01:00
.gitattributes winbuild: MS-DOS batch tidy-ups 2024-07-02 19:26:15 +02:00
.gitignore build: drop the winbuild build system 2025-09-20 01:20:25 +02:00
.mailmap REUSE: add copyright header to two files 2025-11-03 16:08:52 +01:00
acinclude.m4 badwords: add more contractions, fix fallouts 2025-11-17 19:29:15 +01:00
appveyor.sh appveyor: add VS2010 x86 Release VS project job and switch VS2013 to x64 2025-11-17 15:50:24 +01:00
appveyor.yml appveyor: add VS2010 x86 Release VS project job and switch VS2013 to x64 2025-11-17 15:50:24 +01:00
buildconf copyright: update all copyright lines and remove year ranges 2023-01-03 09:19:21 +01:00
CHANGES.md CHANGES: rename to CHANGES.md, no longer generated 2024-08-01 13:37:12 +02:00
CMakeLists.txt cmake: add support for libbacktrace, fix two build issues 2025-11-24 14:29:29 +01:00
configure.ac memdebug: produce stack trace dump with libbacktrace 2025-11-24 11:58:18 +01:00
COPYING COPYING: bump copyright year range to 1996 - 2025 2025-01-01 21:12:12 +01:00
curl-config.in curl-config: remove X prefix use 2025-08-04 10:01:07 +02:00
Dockerfile Dockerfile: update debian:bookworm-slim digest to 936abff 2025-11-05 15:24:21 +01:00
GIT-INFO.md REUSE: add copyright header to two files 2025-11-03 16:08:52 +01:00
libcurl.pc.in configure: do not echo most inherited LDFLAGS to config files 2024-11-14 09:55:45 +01:00
Makefile.am cmake: add support for libbacktrace, fix two build issues 2025-11-24 14:29:29 +01:00
README krb5: drop support for Kerberos FTP 2025-09-20 23:58:28 +02:00
README.md badwords: re-sync with curl-www, fix issues found 2025-11-12 00:53:44 +01:00
RELEASE-NOTES RELEASE-NOTES: synced 2025-11-24 23:32:59 +01:00
renovate.json renovate.json: replace CI: prefix with GHA: 2025-11-17 16:50:20 +01:00
REUSE.toml tests/data: add %includetext, dedupe XML payloads into external file 2025-11-13 12:24:50 +01:00
SECURITY.md docs: Clarify OpenSSF Best Practices vs Scorecard 2024-08-22 11:50:20 +02:00

curl logo

curl is a command-line tool for transferring data from or to a server using URLs. It supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP, SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS.

Learn how to use curl by reading the man page or everything curl.

Find out how to install curl by reading the INSTALL document.

libcurl is the library curl is using to do its job. It is readily available to be used by your software. Read the libcurl man page to learn how.

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curl is Open Source and is distributed under an MIT-like license.

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