curl/docs/libcurl/curl_formget.md
Daniel Stenberg eefcc1bda4
docs: introduce "curldown" for libcurl man page format
curldown is this new file format for libcurl man pages. It is markdown
inspired with differences:

- Each file has a set of leading headers with meta-data
- Supports a small subset of markdown
- Uses .md file extensions for editors/IDE/GitHub to treat them nicely
- Generates man pages very similar to the previous ones
- Generates man pages that still convert nicely to HTML on the website
- Detects and highlights mentions of curl symbols automatically (when
  their man page section is specified)

tools:

- cd2nroff: converts from curldown to nroff man page
- nroff2cd: convert an (old) nroff man page to curldown
- cdall: convert many nroff pages to curldown versions
- cd2cd: verifies and updates a curldown to latest curldown

This setup generates .3 versions of all the curldown versions at build time.

CI:

Since the documentation is now technically markdown in the eyes of many
things, the CI runs many more tests and checks on this documentation,
including proselint, link checkers and tests that make sure we capitalize the
first letter after a period...

Closes #12730
2024-01-23 00:29:02 +01:00

1.7 KiB

c SPDX-License-Identifier Title Section Source See-also
Copyright (C) Daniel Stenberg, <daniel.se>, et al. curl curl_formget 3 libcurl
curl_formadd (3)
curl_mime_init (3)

NAME

curl_formget - serialize a previously built multipart form POST chain

SYNOPSIS

#include <curl/curl.h>

int curl_formget(struct curl_httppost * form, void *userp,
                 curl_formget_callback append);

DESCRIPTION

curl_formget() serializes data previously built with curl_formadd(3). It accepts a void pointer as second argument named userp which is passed as the first argument to the curl_formget_callback function.

 typedef size_t (*curl_formget_callback)(void *userp, const char *buf,
                                         size_t len);"

The curl_formget_callback is invoked for each part of the HTTP POST chain. The character buffer passed to the callback must not be freed. The callback should return the buffer length passed to it on success.

If the CURLFORM_STREAM option is used in the formpost, it prevents curl_formget(3) from working until you have performed the actual HTTP request. This, because first then does libcurl known which actual read callback to use!

EXAMPLE

size_t print_httppost_callback(void *arg, const char *buf, size_t len)
{
  fwrite(buf, len, 1, stdout);
  (*(size_t *) arg) += len;
  return len;
}

size_t print_httppost(struct curl_httppost *post)
{
  size_t total_size = 0;
  if(curl_formget(post, &total_size, print_httppost_callback)) {
    return (size_t) -1;
  }
  return total_size;
}

AVAILABILITY

This function was added in libcurl 7.15.5. The form API is deprecated in libcurl 7.56.0.

RETURN VALUE

0 means everything was OK, non-zero means an error occurred