eefcc1bda4
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
103 lines
2.9 KiB
Markdown
103 lines
2.9 KiB
Markdown
---
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c: Copyright (C) Daniel Stenberg, <daniel.se>, et al.
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SPDX-License-Identifier: curl
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Title: curl_multi_info_read
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Section: 3
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Source: libcurl
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See-also:
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- curl_multi_cleanup (3)
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- curl_multi_init (3)
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- curl_multi_perform (3)
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---
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# NAME
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curl_multi_info_read - read multi stack information
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# SYNOPSIS
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~~~c
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#include <curl/curl.h>
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CURLMsg *curl_multi_info_read(CURLM *multi_handle, int *msgs_in_queue);
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~~~
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# DESCRIPTION
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Ask the multi handle if there are any messages from the individual
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transfers. Messages may include information such as an error code from the
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transfer or just the fact that a transfer is completed. More details on these
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should be written down as well.
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Repeated calls to this function returns a new struct each time, until a NULL
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is returned as a signal that there is no more to get at this point. The
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integer pointed to with *msgs_in_queue* contains the number of remaining
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messages after this function was called.
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When you fetch a message using this function, it is removed from the internal
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queue so calling this function again does not return the same message
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again. It instead returns new messages at each new invoke until the queue is
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emptied.
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**WARNING:** The data the returned pointer points to does not survive
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calling curl_multi_cleanup(3), curl_multi_remove_handle(3) or
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curl_easy_cleanup(3).
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The *CURLMsg* struct is simple and only contains basic information. If
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more involved information is wanted, the particular "easy handle" is present
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in that struct and can be used in subsequent regular
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curl_easy_getinfo(3) calls (or similar):
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~~~c
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struct CURLMsg {
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CURLMSG msg; /* what this message means */
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CURL *easy_handle; /* the handle it concerns */
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union {
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void *whatever; /* message-specific data */
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CURLcode result; /* return code for transfer */
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} data;
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};
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~~~
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When **msg** is *CURLMSG_DONE*, the message identifies a transfer that
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is done, and then **result** contains the return code for the easy handle
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that just completed.
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At this point, there are no other **msg** types defined.
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# EXAMPLE
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~~~c
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int main(void)
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{
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CURLM *multi = curl_multi_init();
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CURL *curl = curl_easy_init();
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if(curl) {
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struct CURLMsg *m;
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/* call curl_multi_perform or curl_multi_socket_action first, then loop
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through and check if there are any transfers that have completed */
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do {
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int msgq = 0;
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m = curl_multi_info_read(multi, &msgq);
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if(m && (m->msg == CURLMSG_DONE)) {
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CURL *e = m->easy_handle;
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/* m->data.result holds the error code for the transfer */
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curl_multi_remove_handle(multi, e);
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curl_easy_cleanup(e);
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}
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} while(m);
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}
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}
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~~~
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# AVAILABILITY
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Added in 7.9.6
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# RETURN VALUE
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A pointer to a filled-in struct, or NULL if it failed or ran out of
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structs. It also writes the number of messages left in the queue (after this
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read) in the integer the second argument points to.
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