docs/examples/evhiperfifo.c - third_party/curl - Git at Google

 /***************************************************************************
  *                                  _   _ ____  _
  *  Project                     ___| | | |  _ \| |
  *                             / __| | | | |_) | |
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
  * Copyright (C) 1998 - 2019, 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.haxx.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.
  *
  ***************************************************************************/
 /* <DESC>
  * multi socket interface together with libev
  * </DESC>
  */
 /* Example application source code using the multi socket interface to
  * download many files at once.
  *
  * This example features the same basic functionality as hiperfifo.c does,
  * but this uses libev instead of libevent.
  *
  * Written by Jeff Pohlmeyer, converted to use libev by Markus Koetter

 Requires libev and a (POSIX?) system that has mkfifo().

 This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
 sample programs.

 When running, the program creates the named pipe "hiper.fifo"

 Whenever there is input into the fifo, the program reads the input as a list
 of URL's and creates some new easy handles to fetch each URL via the
 curl_multi "hiper" API.


 Thus, you can try a single URL:
   % echo http://www.yahoo.com > hiper.fifo

 Or a whole bunch of them:
   % cat my-url-list > hiper.fifo

 The fifo buffer is handled almost instantly, so you can even add more URL's
 while the previous requests are still being downloaded.

 Note:
   For the sake of simplicity, URL length is limited to 1023 char's !

 This is purely a demo app, all retrieved data is simply discarded by the write
 callback.

 */

 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
 #include <sys/poll.h>
 #include <curl/curl.h>
 #include <ev.h>
 #include <fcntl.h>
 #include <sys/stat.h>
 #include <errno.h>

 #define DPRINT(x...) printf(x)

 #define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */


 /* Global information, common to all connections */
 typedef struct _GlobalInfo
 {
   struct ev_loop *loop;
   struct ev_io fifo_event;
   struct ev_timer timer_event;
   CURLM *multi;
   int still_running;
   FILE *input;
 } GlobalInfo;


 /* Information associated with a specific easy handle */
 typedef struct _ConnInfo
 {
   CURL *easy;
   char *url;
   GlobalInfo *global;
   char error[CURL_ERROR_SIZE];
 } ConnInfo;


 /* Information associated with a specific socket */
 typedef struct _SockInfo
 {
   curl_socket_t sockfd;
   CURL *easy;
   int action;
   long timeout;
   struct ev_io ev;
   int evset;
   GlobalInfo *global;
 } SockInfo;

 static void timer_cb(EV_P_ struct ev_timer *w, int revents);

 /* Update the event timer after curl_multi library calls */
 static int multi_timer_cb(CURLM *multi, long timeout_ms, GlobalInfo *g)
 {
   DPRINT("%s %li\n", __PRETTY_FUNCTION__,  timeout_ms);
   ev_timer_stop(g->loop, &g->timer_event);
   if(timeout_ms >= 0) {
     /* -1 means delete, other values are timeout times in milliseconds */
     double  t = timeout_ms / 1000;
     ev_timer_init(&g->timer_event, timer_cb, t, 0.);
     ev_timer_start(g->loop, &g->timer_event);
   }
   return 0;
 }

 /* Die if we get a bad CURLMcode somewhere */
 static void mcode_or_die(const char *where, CURLMcode code)
 {
   if(CURLM_OK != code) {
     const char *s;
     switch(code) {
     case CURLM_BAD_HANDLE:
       s = "CURLM_BAD_HANDLE";
       break;
     case CURLM_BAD_EASY_HANDLE:
       s = "CURLM_BAD_EASY_HANDLE";
       break;
     case CURLM_OUT_OF_MEMORY:
       s = "CURLM_OUT_OF_MEMORY";
       break;
     case CURLM_INTERNAL_ERROR:
       s = "CURLM_INTERNAL_ERROR";
       break;
     case CURLM_UNKNOWN_OPTION:
       s = "CURLM_UNKNOWN_OPTION";
       break;
     case CURLM_LAST:
       s = "CURLM_LAST";
       break;
     default:
       s = "CURLM_unknown";
       break;
     case CURLM_BAD_SOCKET:
       s = "CURLM_BAD_SOCKET";
       fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
       /* ignore this error */
       return;
     }
     fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
     exit(code);
   }
 }


 /* Check for completed transfers, and remove their easy handles */
 static void check_multi_info(GlobalInfo *g)
 {
   char *eff_url;
   CURLMsg *msg;
   int msgs_left;
   ConnInfo *conn;
   CURL *easy;
   CURLcode res;

   fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
   while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
     if(msg->msg == CURLMSG_DONE) {
       easy = msg->easy_handle;
       res = msg->data.result;
       curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
       curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
       fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
       curl_multi_remove_handle(g->multi, easy);
       free(conn->url);
       curl_easy_cleanup(easy);
       free(conn);
     }
   }
 }


 /* Called by libevent when we get action on a multi socket */
 static void event_cb(EV_P_ struct ev_io *w, int revents)
 {
   DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
   GlobalInfo *g = (GlobalInfo*) w->data;
   CURLMcode rc;

   int action = ((revents & EV_READ) ? CURL_POLL_IN : 0) |
     ((revents & EV_WRITE) ? CURL_POLL_OUT : 0);
   rc = curl_multi_socket_action(g->multi, w->fd, action, &g->still_running);
   mcode_or_die("event_cb: curl_multi_socket_action", rc);
   check_multi_info(g);
   if(g->still_running <= 0) {
     fprintf(MSG_OUT, "last transfer done, kill timeout\n");
     ev_timer_stop(g->loop, &g->timer_event);
   }
 }

 /* Called by libevent when our timeout expires */
 static void timer_cb(EV_P_ struct ev_timer *w, int revents)
 {
   DPRINT("%s  w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);

   GlobalInfo *g = (GlobalInfo *)w->data;
   CURLMcode rc;

   rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
                                 &g->still_running);
   mcode_or_die("timer_cb: curl_multi_socket_action", rc);
   check_multi_info(g);
 }

 /* Clean up the SockInfo structure */
 static void remsock(SockInfo *f, GlobalInfo *g)
 {
   printf("%s  \n", __PRETTY_FUNCTION__);
   if(f) {
     if(f->evset)
       ev_io_stop(g->loop, &f->ev);
     free(f);
   }
 }


 /* Assign information to a SockInfo structure */
 static void setsock(SockInfo *f, curl_socket_t s, CURL *e, int act,
                     GlobalInfo *g)
 {
   printf("%s  \n", __PRETTY_FUNCTION__);

   int kind = ((act & CURL_POLL_IN) ? EV_READ : 0) |
              ((act & CURL_POLL_OUT) ? EV_WRITE : 0);

   f->sockfd = s;
   f->action = act;
   f->easy = e;
   if(f->evset)
     ev_io_stop(g->loop, &f->ev);
   ev_io_init(&f->ev, event_cb, f->sockfd, kind);
   f->ev.data = g;
   f->evset = 1;
   ev_io_start(g->loop, &f->ev);
 }


 /* Initialize a new SockInfo structure */
 static void addsock(curl_socket_t s, CURL *easy, int action, GlobalInfo *g)
 {
   SockInfo *fdp = calloc(sizeof(SockInfo), 1);

   fdp->global = g;
   setsock(fdp, s, easy, action, g);
   curl_multi_assign(g->multi, s, fdp);
 }

 /* CURLMOPT_SOCKETFUNCTION */
 static int sock_cb(CURL *e, curl_socket_t s, int what, void *cbp, void *sockp)
 {
   DPRINT("%s e %p s %i what %i cbp %p sockp %p\n",
          __PRETTY_FUNCTION__, e, s, what, cbp, sockp);

   GlobalInfo *g = (GlobalInfo*) cbp;
   SockInfo *fdp = (SockInfo*) sockp;
   const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};

   fprintf(MSG_OUT,
           "socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
   if(what == CURL_POLL_REMOVE) {
     fprintf(MSG_OUT, "\n");
     remsock(fdp, g);
   }
   else {
     if(!fdp) {
       fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
       addsock(s, e, what, g);
     }
     else {
       fprintf(MSG_OUT,
               "Changing action from %s to %s\n",
               whatstr[fdp->action], whatstr[what]);
       setsock(fdp, s, e, what, g);
     }
   }
   return 0;
 }


 /* CURLOPT_WRITEFUNCTION */
 static size_t write_cb(void *ptr, size_t size, size_t nmemb, void *data)
 {
   size_t realsize = size * nmemb;
   ConnInfo *conn = (ConnInfo*) data;
   (void)ptr;
   (void)conn;
   return realsize;
 }


 /* CURLOPT_PROGRESSFUNCTION */
 static int prog_cb(void *p, double dltotal, double dlnow, double ult,
                    double uln)
 {
   ConnInfo *conn = (ConnInfo *)p;
   (void)ult;
   (void)uln;

   fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
   return 0;
 }


 /* Create a new easy handle, and add it to the global curl_multi */
 static void new_conn(char *url, GlobalInfo *g)
 {
   ConnInfo *conn;
   CURLMcode rc;

   conn = calloc(1, sizeof(ConnInfo));
   conn->error[0]='\0';

   conn->easy = curl_easy_init();
   if(!conn->easy) {
     fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
     exit(2);
   }
   conn->global = g;
   conn->url = strdup(url);
   curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
   curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
   curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
   curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
   curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
   curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
   curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
   curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
   curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);

   fprintf(MSG_OUT,
           "Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
   rc = curl_multi_add_handle(g->multi, conn->easy);
   mcode_or_die("new_conn: curl_multi_add_handle", rc);

   /* note that the add_handle() will set a time-out to trigger very soon so
      that the necessary socket_action() call will be called by this app */
 }

 /* This gets called whenever data is received from the fifo */
 static void fifo_cb(EV_P_ struct ev_io *w, int revents)
 {
   char s[1024];
   long int rv = 0;
   int n = 0;
   GlobalInfo *g = (GlobalInfo *)w->data;

   do {
     s[0]='\0';
     rv = fscanf(g->input, "%1023s%n", s, &n);
     s[n]='\0';
     if(n && s[0]) {
       new_conn(s, g);  /* if we read a URL, go get it! */
     }
     else
       break;
   } while(rv != EOF);
 }

 /* Create a named pipe and tell libevent to monitor it */
 static int init_fifo(GlobalInfo *g)
 {
   struct stat st;
   static const char *fifo = "hiper.fifo";
   curl_socket_t sockfd;

   fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
   if(lstat (fifo, &st) == 0) {
     if((st.st_mode & S_IFMT) == S_IFREG) {
       errno = EEXIST;
       perror("lstat");
       exit(1);
     }
   }
   unlink(fifo);
   if(mkfifo (fifo, 0600) == -1) {
     perror("mkfifo");
     exit(1);
   }
   sockfd = open(fifo, O_RDWR | O_NONBLOCK, 0);
   if(sockfd == -1) {
     perror("open");
     exit(1);
   }
   g->input = fdopen(sockfd, "r");

   fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
   ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
   ev_io_start(g->loop, &g->fifo_event);
   return (0);
 }

 int main(int argc, char **argv)
 {
   GlobalInfo g;
   (void)argc;
   (void)argv;

   memset(&g, 0, sizeof(GlobalInfo));
   g.loop = ev_default_loop(0);

   init_fifo(&g);
   g.multi = curl_multi_init();

   ev_timer_init(&g.timer_event, timer_cb, 0., 0.);
   g.timer_event.data = &g;
   g.fifo_event.data = &g;
   curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
   curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
   curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
   curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);

   /* we don't call any curl_multi_socket*() function yet as we have no handles
      added! */

   ev_loop(g.loop, 0);
   curl_multi_cleanup(g.multi);
   return 0;
 }
	/***************************************************************************
	* _ _ ____ _
	* Project ___\| \| \| \| _ \\| \|
	* / __\| \| \| \| \|_) \| \|
	* \| (__\| \|_\| \| _ <\| \|___
	* \___\|\___/\|_\| \_\_____\|
	*
	* Copyright (C) 1998 - 2019, 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.haxx.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.
	*
	***************************************************************************/
	/* <DESC>
	* multi socket interface together with libev
	* </DESC>
	*/
	/* Example application source code using the multi socket interface to
	* download many files at once.
	*
	* This example features the same basic functionality as hiperfifo.c does,
	* but this uses libev instead of libevent.
	*
	* Written by Jeff Pohlmeyer, converted to use libev by Markus Koetter

	Requires libev and a (POSIX?) system that has mkfifo().

	This is an adaptation of libcurl's "hipev.c" and libevent's "event-test.c"
	sample programs.

	When running, the program creates the named pipe "hiper.fifo"

	Whenever there is input into the fifo, the program reads the input as a list
	of URL's and creates some new easy handles to fetch each URL via the
	curl_multi "hiper" API.


	Thus, you can try a single URL:
	% echo http://www.yahoo.com > hiper.fifo

	Or a whole bunch of them:
	% cat my-url-list > hiper.fifo

	The fifo buffer is handled almost instantly, so you can even add more URL's
	while the previous requests are still being downloaded.

	Note:
	For the sake of simplicity, URL length is limited to 1023 char's !

	This is purely a demo app, all retrieved data is simply discarded by the write
	callback.

	*/

	#include <stdio.h>
	#include <string.h>
	#include <stdlib.h>
	#include <sys/time.h>
	#include <time.h>
	#include <unistd.h>
	#include <sys/poll.h>
	#include <curl/curl.h>
	#include <ev.h>
	#include <fcntl.h>
	#include <sys/stat.h>
	#include <errno.h>

	#define DPRINT(x...) printf(x)

	#define MSG_OUT stdout /* Send info to stdout, change to stderr if you want */


	/* Global information, common to all connections */
	typedef struct _GlobalInfo
	{
	struct ev_loop *loop;
	struct ev_io fifo_event;
	struct ev_timer timer_event;
	CURLM *multi;
	int still_running;
	FILE *input;
	} GlobalInfo;


	/* Information associated with a specific easy handle */
	typedef struct _ConnInfo
	{
	CURL *easy;
	char *url;
	GlobalInfo *global;
	char error[CURL_ERROR_SIZE];
	} ConnInfo;


	/* Information associated with a specific socket */
	typedef struct _SockInfo
	{
	curl_socket_t sockfd;
	CURL *easy;
	int action;
	long timeout;
	struct ev_io ev;
	int evset;
	GlobalInfo *global;
	} SockInfo;

	static void timer_cb(EV_P_ struct ev_timer *w, int revents);

	/* Update the event timer after curl_multi library calls */
	static int multi_timer_cb(CURLM multi, long timeout_ms, GlobalInfo g)
	{
	DPRINT("%s %li\n", __PRETTY_FUNCTION__, timeout_ms);
	ev_timer_stop(g->loop, &g->timer_event);
	if(timeout_ms >= 0) {
	/* -1 means delete, other values are timeout times in milliseconds */
	double t = timeout_ms / 1000;
	ev_timer_init(&g->timer_event, timer_cb, t, 0.);
	ev_timer_start(g->loop, &g->timer_event);
	}
	return 0;
	}

	/* Die if we get a bad CURLMcode somewhere */
	static void mcode_or_die(const char *where, CURLMcode code)
	{
	if(CURLM_OK != code) {
	const char *s;
	switch(code) {
	case CURLM_BAD_HANDLE:
	s = "CURLM_BAD_HANDLE";
	break;
	case CURLM_BAD_EASY_HANDLE:
	s = "CURLM_BAD_EASY_HANDLE";
	break;
	case CURLM_OUT_OF_MEMORY:
	s = "CURLM_OUT_OF_MEMORY";
	break;
	case CURLM_INTERNAL_ERROR:
	s = "CURLM_INTERNAL_ERROR";
	break;
	case CURLM_UNKNOWN_OPTION:
	s = "CURLM_UNKNOWN_OPTION";
	break;
	case CURLM_LAST:
	s = "CURLM_LAST";
	break;
	default:
	s = "CURLM_unknown";
	break;
	case CURLM_BAD_SOCKET:
	s = "CURLM_BAD_SOCKET";
	fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
	/* ignore this error */
	return;
	}
	fprintf(MSG_OUT, "ERROR: %s returns %s\n", where, s);
	exit(code);
	}
	}



	/* Check for completed transfers, and remove their easy handles */
	static void check_multi_info(GlobalInfo *g)
	{
	char *eff_url;
	CURLMsg *msg;
	int msgs_left;
	ConnInfo *conn;
	CURL *easy;
	CURLcode res;

	fprintf(MSG_OUT, "REMAINING: %d\n", g->still_running);
	while((msg = curl_multi_info_read(g->multi, &msgs_left))) {
	if(msg->msg == CURLMSG_DONE) {
	easy = msg->easy_handle;
	res = msg->data.result;
	curl_easy_getinfo(easy, CURLINFO_PRIVATE, &conn);
	curl_easy_getinfo(easy, CURLINFO_EFFECTIVE_URL, &eff_url);
	fprintf(MSG_OUT, "DONE: %s => (%d) %s\n", eff_url, res, conn->error);
	curl_multi_remove_handle(g->multi, easy);
	free(conn->url);
	curl_easy_cleanup(easy);
	free(conn);
	}
	}
	}



	/* Called by libevent when we get action on a multi socket */
	static void event_cb(EV_P_ struct ev_io *w, int revents)
	{
	DPRINT("%s w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);
	GlobalInfo g = (GlobalInfo) w->data;
	CURLMcode rc;

	int action = ((revents & EV_READ) ? CURL_POLL_IN : 0) \|
	((revents & EV_WRITE) ? CURL_POLL_OUT : 0);
	rc = curl_multi_socket_action(g->multi, w->fd, action, &g->still_running);
	mcode_or_die("event_cb: curl_multi_socket_action", rc);
	check_multi_info(g);
	if(g->still_running <= 0) {
	fprintf(MSG_OUT, "last transfer done, kill timeout\n");
	ev_timer_stop(g->loop, &g->timer_event);
	}
	}

	/* Called by libevent when our timeout expires */
	static void timer_cb(EV_P_ struct ev_timer *w, int revents)
	{
	DPRINT("%s w %p revents %i\n", __PRETTY_FUNCTION__, w, revents);

	GlobalInfo g = (GlobalInfo )w->data;
	CURLMcode rc;

	rc = curl_multi_socket_action(g->multi, CURL_SOCKET_TIMEOUT, 0,
	&g->still_running);
	mcode_or_die("timer_cb: curl_multi_socket_action", rc);
	check_multi_info(g);
	}

	/* Clean up the SockInfo structure */
	static void remsock(SockInfo f, GlobalInfo g)
	{
	printf("%s \n", __PRETTY_FUNCTION__);
	if(f) {
	if(f->evset)
	ev_io_stop(g->loop, &f->ev);
	free(f);
	}
	}



	/* Assign information to a SockInfo structure */
	static void setsock(SockInfo f, curl_socket_t s, CURL e, int act,
	GlobalInfo *g)
	{
	printf("%s \n", __PRETTY_FUNCTION__);

	int kind = ((act & CURL_POLL_IN) ? EV_READ : 0) \|
	((act & CURL_POLL_OUT) ? EV_WRITE : 0);

	f->sockfd = s;
	f->action = act;
	f->easy = e;
	if(f->evset)
	ev_io_stop(g->loop, &f->ev);
	ev_io_init(&f->ev, event_cb, f->sockfd, kind);
	f->ev.data = g;
	f->evset = 1;
	ev_io_start(g->loop, &f->ev);
	}



	/* Initialize a new SockInfo structure */
	static void addsock(curl_socket_t s, CURL easy, int action, GlobalInfo g)
	{
	SockInfo *fdp = calloc(sizeof(SockInfo), 1);

	fdp->global = g;
	setsock(fdp, s, easy, action, g);
	curl_multi_assign(g->multi, s, fdp);
	}

	/* CURLMOPT_SOCKETFUNCTION */
	static int sock_cb(CURL e, curl_socket_t s, int what, void cbp, void *sockp)
	{
	DPRINT("%s e %p s %i what %i cbp %p sockp %p\n",
	__PRETTY_FUNCTION__, e, s, what, cbp, sockp);

	GlobalInfo g = (GlobalInfo) cbp;
	SockInfo fdp = (SockInfo) sockp;
	const char *whatstr[]={ "none", "IN", "OUT", "INOUT", "REMOVE"};

	fprintf(MSG_OUT,
	"socket callback: s=%d e=%p what=%s ", s, e, whatstr[what]);
	if(what == CURL_POLL_REMOVE) {
	fprintf(MSG_OUT, "\n");
	remsock(fdp, g);
	}
	else {
	if(!fdp) {
	fprintf(MSG_OUT, "Adding data: %s\n", whatstr[what]);
	addsock(s, e, what, g);
	}
	else {
	fprintf(MSG_OUT,
	"Changing action from %s to %s\n",
	whatstr[fdp->action], whatstr[what]);
	setsock(fdp, s, e, what, g);
	}
	}
	return 0;
	}


	/* CURLOPT_WRITEFUNCTION */
	static size_t write_cb(void ptr, size_t size, size_t nmemb, void data)
	{
	size_t realsize = size * nmemb;
	ConnInfo conn = (ConnInfo) data;
	(void)ptr;
	(void)conn;
	return realsize;
	}


	/* CURLOPT_PROGRESSFUNCTION */
	static int prog_cb(void *p, double dltotal, double dlnow, double ult,
	double uln)
	{
	ConnInfo conn = (ConnInfo )p;
	(void)ult;
	(void)uln;

	fprintf(MSG_OUT, "Progress: %s (%g/%g)\n", conn->url, dlnow, dltotal);
	return 0;
	}


	/* Create a new easy handle, and add it to the global curl_multi */
	static void new_conn(char url, GlobalInfo g)
	{
	ConnInfo *conn;
	CURLMcode rc;

	conn = calloc(1, sizeof(ConnInfo));
	conn->error[0]='\0';

	conn->easy = curl_easy_init();
	if(!conn->easy) {
	fprintf(MSG_OUT, "curl_easy_init() failed, exiting!\n");
	exit(2);
	}
	conn->global = g;
	conn->url = strdup(url);
	curl_easy_setopt(conn->easy, CURLOPT_URL, conn->url);
	curl_easy_setopt(conn->easy, CURLOPT_WRITEFUNCTION, write_cb);
	curl_easy_setopt(conn->easy, CURLOPT_WRITEDATA, conn);
	curl_easy_setopt(conn->easy, CURLOPT_VERBOSE, 1L);
	curl_easy_setopt(conn->easy, CURLOPT_ERRORBUFFER, conn->error);
	curl_easy_setopt(conn->easy, CURLOPT_PRIVATE, conn);
	curl_easy_setopt(conn->easy, CURLOPT_NOPROGRESS, 0L);
	curl_easy_setopt(conn->easy, CURLOPT_PROGRESSFUNCTION, prog_cb);
	curl_easy_setopt(conn->easy, CURLOPT_PROGRESSDATA, conn);
	curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_TIME, 3L);
	curl_easy_setopt(conn->easy, CURLOPT_LOW_SPEED_LIMIT, 10L);

	fprintf(MSG_OUT,
	"Adding easy %p to multi %p (%s)\n", conn->easy, g->multi, url);
	rc = curl_multi_add_handle(g->multi, conn->easy);
	mcode_or_die("new_conn: curl_multi_add_handle", rc);

	/* note that the add_handle() will set a time-out to trigger very soon so
	that the necessary socket_action() call will be called by this app */
	}

	/* This gets called whenever data is received from the fifo */
	static void fifo_cb(EV_P_ struct ev_io *w, int revents)
	{
	char s[1024];
	long int rv = 0;
	int n = 0;
	GlobalInfo g = (GlobalInfo )w->data;

	do {
	s[0]='\0';
	rv = fscanf(g->input, "%1023s%n", s, &n);
	s[n]='\0';
	if(n && s[0]) {
	new_conn(s, g); /* if we read a URL, go get it! */
	}
	else
	break;
	} while(rv != EOF);
	}

	/* Create a named pipe and tell libevent to monitor it */
	static int init_fifo(GlobalInfo *g)
	{
	struct stat st;
	static const char *fifo = "hiper.fifo";
	curl_socket_t sockfd;

	fprintf(MSG_OUT, "Creating named pipe \"%s\"\n", fifo);
	if(lstat (fifo, &st) == 0) {
	if((st.st_mode & S_IFMT) == S_IFREG) {
	errno = EEXIST;
	perror("lstat");
	exit(1);
	}
	}
	unlink(fifo);
	if(mkfifo (fifo, 0600) == -1) {
	perror("mkfifo");
	exit(1);
	}
	sockfd = open(fifo, O_RDWR \| O_NONBLOCK, 0);
	if(sockfd == -1) {
	perror("open");
	exit(1);
	}
	g->input = fdopen(sockfd, "r");

	fprintf(MSG_OUT, "Now, pipe some URL's into > %s\n", fifo);
	ev_io_init(&g->fifo_event, fifo_cb, sockfd, EV_READ);
	ev_io_start(g->loop, &g->fifo_event);
	return (0);
	}

	int main(int argc, char **argv)
	{
	GlobalInfo g;
	(void)argc;
	(void)argv;

	memset(&g, 0, sizeof(GlobalInfo));
	g.loop = ev_default_loop(0);

	init_fifo(&g);
	g.multi = curl_multi_init();

	ev_timer_init(&g.timer_event, timer_cb, 0., 0.);
	g.timer_event.data = &g;
	g.fifo_event.data = &g;
	curl_multi_setopt(g.multi, CURLMOPT_SOCKETFUNCTION, sock_cb);
	curl_multi_setopt(g.multi, CURLMOPT_SOCKETDATA, &g);
	curl_multi_setopt(g.multi, CURLMOPT_TIMERFUNCTION, multi_timer_cb);
	curl_multi_setopt(g.multi, CURLMOPT_TIMERDATA, &g);

	/* we don't call any curl_multi_socket*() function yet as we have no handles
	added! */

	ev_loop(g.loop, 0);
	curl_multi_cleanup(g.multi);
	return 0;
	}