Change #263970

Comments

docs: use the correct CURLOPT_WRITEFUNCTION signature

In order to not encourage users to use incompatible function pointers,
change the callback function definitions to use `char *` instead of
`void *` for the first argument.

Triggered by https://stackoverflow.com/questions/79921871/curl-c-c-library-based-application-produces-erronious-response-for-http-post-r#comment141032037_79921871 :

"The code was mostly modified from
 [this example code](https://curl.se/libcurl/c/postinmemory.html),
 honestly I never knew this is wrong. Thanks for pointing it out."

Signed-off-by: Ted Lyngmo <ted@lyncon.se>
Closes #21265

Changed files

• docs/FAQ.md
• docs/examples/cacertinmem.c
• docs/examples/certinfo.c
• docs/examples/chkspeed.c
• docs/examples/crawler.c
• docs/examples/ephiperfifo.c
• docs/examples/evhiperfifo.c
• docs/examples/externalsocket.c
• docs/examples/ftp-delete.c
• docs/examples/ftpget.c
• docs/examples/ftpsget.c
• docs/examples/ftpuploadresume.c
• docs/examples/getinmemory.c
• docs/examples/ghiper.c
• docs/examples/hiperfifo.c
• docs/examples/http2-pushinmemory.c
• docs/examples/postinmemory.c
• docs/examples/sepheaders.c
• docs/examples/sessioninfo.c
• docs/examples/sftpget.c
• docs/examples/synctime.c
• docs/examples/url2file.c
• docs/examples/usercertinmem.c
• docs/libcurl/libcurl-tutorial.md
• docs/libcurl/opts/CURLINFO_TLS_SSL_PTR.md
• tests/libtest/lib3102.c