curl/packages/OS400/rpg-examples/HEADERAPI

      * Curl header API: extract headers post transfer
      *
     h DFTACTGRP(*NO) ACTGRP(*NEW)
     h OPTION(*NOSHOWCPY)
     h BNDDIR('CURL')
      *
      **************************************************************************
      *                                  _   _ ____  _
      *  Project                     ___| | | |  _ \| |
      *                             / __| | | | |_) | |
      *                            | (__| |_| |  _ <| |___
      *                             \___|\___/|_| \_\_____|
      *
      * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
      *
      * This software is licensed as described in the file COPYING, which
      * you should have received as part of this distribution. The terms
      * are also available at https://curl.se/docs/copyright.html.
      *
      * You may opt to use, copy, modify, merge, publish, distribute and/or sell
      * copies of the Software, and permit persons to whom the Software is
      * furnished to do so, under the terms of the COPYING file.
      *
      * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF
      * ANY KIND, either express or implied.
      *
      * SPDX-License-Identifier: curl
      *
      **************************************************************************
      *
      /include H,CURL.INC
      *
      * Extract headers post transfer with the header API.
      *
     d                 pi
     d url                          120
      *
     d urllen          s             10u 0                                      URL length
      *
      **************************************************************************

        urllen = trimmed_length(url: %len(url));

        // Do the curl stuff.

        curl_global_init(CURL_GLOBAL_ALL);
        main();
        curl_global_cleanup();
        *inlr = *on;            // Exit
      *
      **************************************************************************
      * Main procedure: do the curl job.
      **************************************************************************
      *
     p main            b
     d main            pi
      *
     d h               s               *                                        Easy handle
     d result          s                   like(CURLcode)                       Curl return code
     d                                     inz(CURLE_OUT_OF_MEMORY)
     d header          ds                  likeds(curl_header) based(hp)
     d strp1           s               *                                        Work string pointer
     d strp2           s               *                                        Work string pointer
     d inout           s             52                                         For error display

        // Create and fill curl handle.

        h = curl_easy_init();
        if h <> *NULL;
            curl_easy_setopt_ccsid(h: CURLOPT_URL: %subst(url: 1: urllen): 0);
            curl_easy_setopt(h: CURLOPT_FOLLOWLOCATION: 1);
            curl_easy_setopt(h: CURLOPT_WRITEFUNCTION: %paddr(in_data_cb));     // Ignore input data

            // Perform the request.

            result = curl_easy_perform(h);
        endif;

        // Check for error and report if some.

        if result <> CURLE_OK;
            inout = %str(curl_easy_strerror_ccsid(result: 0));
            dsply '' '*EXT' inout;
        else;
            if curl_easy_header_ccsid(h: 'Content-Type': 0: CURLH_HEADER: -1:
                                      hp: 0) = CURLHE_OK;
                strp2 = curl_to_ccsid(header.value: 0);
                inout = 'Content-Type: ' + %str(strp2);
                dsply inout;
                curl_free(strp2);
            endif;
            dsply '    All server headers:';
            hp = *NULL;
            dow *on;
                hp = curl_easy_nextheader(h: CURLH_HEADER: -1: hp);
                if hp = *NULL;
                    leave;
                endif;
                strp1 = curl_to_ccsid(header.name: 0);
                strp2 = curl_to_ccsid(header.value: 0);
                inout = %str(strp1) + ': ' + %str(strp2) +
                        ' (' + %char(header.amount) + ')';
                curl_free(strp2);
                curl_free(strp1);
                dsply inout;
            enddo;
            inout = 'Done';
            dsply '' '*EXT' inout;
            curl_easy_cleanup(h);       // Release handle
        endif;
     p main            e
      *
      **************************************************************************
      * Dummy data input callback procedure.
      **************************************************************************
      *
     p in_data_cb      b
     d in_data_cb      pi            10u 0
     d  ptr                            *   value                                Input data pointer
     d  size                         10u 0 value                                Data element size
     d  nmemb                        10u 0 value                                Data element count
     d  userdata                       *   value                                User data pointer
      *
        return size * nmemb;
     p in_data_cb      e
      *
      **************************************************************************
      * Get the length of right-trimmed string
      **************************************************************************
      *
     p trimmed_length  b
     d trimmed_length  pi            10u 0
     d  string                   999999    const options(*varsize)
     d  length                       10u 0 value
      *
     d len             s             10u 0
      *
        len = %scan(X'00': string: 1: length); // Limit to zero-terminated string
        if len = 0;
            len = length + 1;
        endif;
        if len <= 1;
            return 0;
        endif;
        return %checkr(' ': string: len - 1);  // Trim right
     p trimmed_length  e