1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) haxx.se>, et al. 9 * 10 * This software is licensed as described in the file COPYING, which 11 * you should have received as part of this distribution. The terms 12 * are also available at https://curl.haxx.se/docs/copyright.html. 13 * 14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell 15 * copies of the Software, and permit persons to whom the Software is 16 * furnished to do so, under the terms of the COPYING file. 17 * 18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY 19 * KIND, either express or implied. 20 * 21 ***************************************************************************/ 22 23 /* <DESC> 24 * POP3 example using the multi interface 25 * </DESC> 26 */ 27 28 #include <stdio.h> 29 #include <string.h> 30 #include <curl/curl.h> 31 32 /* This is a simple example showing how to retrieve mail using libcurl's POP3 33 * capabilities. It builds on the pop3-retr.c example to demonstrate how to use 34 * libcurl's multi interface. 35 * 36 * Note that this example requires libcurl 7.20.0 or above. 37 */ 38 39 #define MULTI_PERFORM_HANG_TIMEOUT 60 * 1000 40 41 static struct timeval tvnow(void) 42 { 43 struct timeval now; 44 45 /* time() returns the value of time in seconds since the epoch */ 46 now.tv_sec = (long)time(NULL); 47 now.tv_usec = 0; 48 49 return now; 50 } 51 52 static long tvdiff(struct timeval newer, struct timeval older) 53 { 54 return (newer.tv_sec - older.tv_sec) * 1000 + 55 (newer.tv_usec - older.tv_usec) / 1000; 56 } 57 58 int main(void) 59 { 60 CURL *curl; 61 CURLM *mcurl; 62 int still_running = 1; 63 struct timeval mp_start; 64 65 curl_global_init(CURL_GLOBAL_DEFAULT); 66 67 curl = curl_easy_init(); 68 if(!curl) 69 return 1; 70 71 mcurl = curl_multi_init(); 72 if(!mcurl) 73 return 2; 74 75 /* Set username and password */ 76 curl_easy_setopt(curl, CURLOPT_USERNAME, "user"); 77 curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret"); 78 79 /* This will retrieve message 1 from the user's mailbox */ 80 curl_easy_setopt(curl, CURLOPT_URL, "pop3://pop.example.com/1"); 81 82 /* Tell the multi stack about our easy handle */ 83 curl_multi_add_handle(mcurl, curl); 84 85 /* Record the start time which we can use later */ 86 mp_start = tvnow(); 87 88 /* We start some action by calling perform right away */ 89 curl_multi_perform(mcurl, &still_running); 90 91 while(still_running) { 92 struct timeval timeout; 93 fd_set fdread; 94 fd_set fdwrite; 95 fd_set fdexcep; 96 int maxfd = -1; 97 int rc; 98 CURLMcode mc; /* curl_multi_fdset() return code */ 99 100 long curl_timeo = -1; 101 102 /* Initialise the file descriptors */ 103 FD_ZERO(&fdread); 104 FD_ZERO(&fdwrite); 105 FD_ZERO(&fdexcep); 106 107 /* Set a suitable timeout to play around with */ 108 timeout.tv_sec = 1; 109 timeout.tv_usec = 0; 110 111 curl_multi_timeout(mcurl, &curl_timeo); 112 if(curl_timeo >= 0) { 113 timeout.tv_sec = curl_timeo / 1000; 114 if(timeout.tv_sec > 1) 115 timeout.tv_sec = 1; 116 else 117 timeout.tv_usec = (curl_timeo % 1000) * 1000; 118 } 119 120 /* get file descriptors from the transfers */ 121 mc = curl_multi_fdset(mcurl, &fdread, &fdwrite, &fdexcep, &maxfd); 122 123 if(mc != CURLM_OK) { 124 fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc); 125 break; 126 } 127 128 /* On success the value of maxfd is guaranteed to be >= -1. We call 129 select(maxfd + 1, ...); specially in case of (maxfd == -1) there are 130 no fds ready yet so we call select(0, ...) --or Sleep() on Windows-- 131 to sleep 100ms, which is the minimum suggested value in the 132 curl_multi_fdset() doc. */ 133 134 if(maxfd == -1) { 135 #ifdef _WIN32 136 Sleep(100); 137 rc = 0; 138 #else 139 /* Portable sleep for platforms other than Windows. */ 140 struct timeval wait = { 0, 100 * 1000 }; /* 100ms */ 141 rc = select(0, NULL, NULL, NULL, &wait); 142 #endif 143 } 144 else { 145 /* Note that on some platforms 'timeout' may be modified by select(). 146 If you need access to the original value save a copy beforehand. */ 147 rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout); 148 } 149 150 if(tvdiff(tvnow(), mp_start) > MULTI_PERFORM_HANG_TIMEOUT) { 151 fprintf(stderr, 152 "ABORTING: Since it seems that we would have run forever.\n"); 153 break; 154 } 155 156 switch(rc) { 157 case -1: /* select error */ 158 break; 159 case 0: /* timeout */ 160 default: /* action */ 161 curl_multi_perform(mcurl, &still_running); 162 break; 163 } 164 } 165 166 /* Always cleanup */ 167 curl_multi_remove_handle(mcurl, curl); 168 curl_multi_cleanup(mcurl); 169 curl_easy_cleanup(curl); 170 curl_global_cleanup(); 171 172 return 0; 173 } 174
