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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Viktor Szakats 1671ebd975
build: drop superfluous STDC_HEADERS macro
It is traditionally defined by autotools to detect the presence of set
of standard C89 headers. autoconf 2.70 (2020-12-08) reduced the headers
covered to `stdlib.h`, `string.h`. After 2.59d (2006-06-05) obsoleting
it earlier. CMake replicated this detection, and curl included
`curl/stdcheaders.h` if standard headers were missing. However, such
condition could never happen because curl sources already assume all
checked standard headers (`stdarg.h`, `stdlib.h`, `string.h`) and
include them unconditionally.

Since this is an unused feature detection and an impossible fallback
path, drop them from CMake and curl's source. autotools continues to do
the detection by default, but its result is unused after this patch.

This leaves public `curl/stdcheaders.h` unused from within the codebase.

Refs:
f0c7c42553
86c213d0e3

Follow-up to 65dae4ad80 #22191
Follow-up to 4c5307b456
Ref: ae1912cb0d

Closes #22206
2026-06-29 11:11:16 +02:00
.circleci runtests: detect bad libssh differently for test 1459 (fixing CircleCI libssh job) 2025-11-16 23:28:44 +01:00
.github build: drop superfluous STDC_HEADERS macro 2026-06-29 11:11:16 +02:00
CMake build: drop superfluous STDC_HEADERS macro 2026-06-29 11:11:16 +02:00
docs cmake: minor tidy-ups 2026-06-27 11:56:18 +02:00
include RELEASE-NOTES: synced 2026-06-25 08:42:02 +02:00
lib build: drop superfluous STDC_HEADERS macro 2026-06-29 11:11:16 +02:00
LICENSES spacecheck: check long lines and repeat spaces, fix fallouts 2026-03-25 11:02:08 +01:00
m4 build: always use local inet_pton()/inet_ntop() implementations 2026-06-27 01:24:39 +02:00
projects build: drop superfluous STDC_HEADERS macro 2026-06-29 11:11:16 +02:00
scripts build: always use local inet_pton()/inet_ntop() implementations 2026-06-27 01:24:39 +02:00
src tidy-up: syntax and code nits 2026-06-26 15:45:24 +02:00
tests build: always use local inet_pton()/inet_ntop() implementations 2026-06-27 01:24:39 +02:00
.clang-tidy.yml clang-tidy: enable more checks, fix fallouts 2026-04-14 02:20:16 +02:00
.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 buildconf: remove 2026-04-04 11:35:24 +02:00
.gitignore build: drop the winbuild build system 2025-09-20 01:20:25 +02:00
.mailmap RELEASE-NOTES: synced 2026-06-26 23:17:26 +02:00
acinclude.m4 tidy-up: docs, comments, typos, whitespace 2026-06-26 11:36:09 +02:00
appveyor.sh scripts: use end-of-options marker in cd, mkdir, mv, sha256sum commands 2026-06-25 11:32:36 +02:00
appveyor.yml appveyor: bump 3 VS2022 jobs to VS2026 2026-06-09 21:16:54 +02:00
CHANGES.md CHANGES: fix typo in filename 2026-01-01 12:20:10 +01:00
CMakeLists.txt build: drop superfluous STDC_HEADERS macro 2026-06-29 11:11:16 +02:00
configure.ac build: always use local inet_pton()/inet_ntop() implementations 2026-06-27 01:24:39 +02:00
COPYING COPYING: bump copyright year range to 1996 - 2026 2026-01-08 23:19:44 +01:00
curl-config.in autotools: tidy-up if expressions 2025-12-10 22:29:19 +01:00
Dockerfile GHA: update debian:bookworm-slim Docker digest to 60eac75 2026-06-24 11:42:21 +02:00
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 autotools: minor fixes and improvements 2026-06-25 11:32:36 +02:00
README BUG-BOUNTY.md: we stop the bug-bounty end of Jan 2026 2026-01-26 08:26:28 +01:00
README.md rtmp: drop support 2026-03-21 14:56:06 +01:00
RELEASE-NOTES RELEASE-NOTES: synced 2026-06-26 23:17:26 +02:00
renovate.json renovate: use standard bump formula for OpenSSL 2026-04-15 10:17:33 +02:00
REUSE.toml github: Add AI usage warning to issue, doc and PR templates 2026-06-02 13:47:01 -04:00
SECURITY.md stop using the word 'just' 2026-03-03 15:30:22 +01:00

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, MQTTS, POP3, POP3S, 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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