getaddrinfo

问题 I am trying to create a simple program that gets the ip address given a certain hostname: My code snipped is attached below: #include<stdio.h> #include<stdlib.h> #include<stdio.h> #include<netdb.h> #include<sys/socket.h> #include<errno.h> #include<arpa/inet.h> #include<string.h> #include<unistd.h> int main(int argc, char *argv[]) { if(argc<2){ printf("Please provide a hostname.\n"); exit(1); } char *hostname = argv[1]; char ip[100]; get_ip(hostname,ip); printf("%s resolved to %s\n",hostname

问题 I am trying to read all the information about specific host and print out every information. I can read and print out all the addresses but I am not reading any ai_canonname! First I thought my examples(www.google.com|www.irs.gov|...) don't have canon name, but after a while I figured I am not getting any name at all. Do you think I am doing something wrong or do you have an example that would work? Here is my code, #include <stdio.h> #include <sys/types.h> #include <sys/socket.h> #include

问题 I'm trying to code a program in C that uses sockets to fetch webpages. My code currently prints successfully the HTML code at some webpages, but not all webpages. In the instances where it does not work I get the following error: Name or service not known Can someone please offer me a solution? The error occurs when executing getaddrinfo. I can't seem to figure it out after an extensive search for the answer. Thanks everyone! My code is as follows: #include <errno.h> #include <string.h>

问题 Can someone help me on how I can catch this error? import pygeoip gi = pygeoip.GeoIP('GeoIP.dat') print gi.country_code_by_name('specificdownload.com') Traceback (most recent call last): File "<module1>", line 14, in <module> File "build\bdist.win-amd64\egg\pygeoip\__init__.py", line 447, in country_code_by_name addr = self._gethostbyname(hostname) File "build\bdist.win-amd64\egg\pygeoip\__init__.py", line 392, in _gethostbyname return socket.gethostbyname(hostname) gaierror: [Errno 11001]

问题 I'm trying to execute API.AI tutorial for building a weather bot for Google Assistant (the one here: https://dialogflow.com/docs/getting-started/basic-fulfillment-conversation) I made everything successfully, created the bot within API, created the Fulfillments, installed NodeJS on my pc, connected Google Cloud Platform, etc. Then I created the index.js file by copying it exactly how it's stated on API.ai tutorial with my API key from World Weather Organisation (see below). But when I use the

问题 The getaddrinfo() function not only allows for client programs to efficiently find the correct data for creating a socket to a given host, it also allows for servers to bind to the correct socket - in theory. I just learned about that and started to play around with it via Python: from socket import * for i in getaddrinfo(None, 22, AF_UNSPEC, SOCK_STREAM, IPPROTO_IP, AI_PASSIVE): i yields (2, 1, 6, '', ('0.0.0.0', 22)) (10, 1, 6, '', ('::', 22, 0, 0)) what makes me wonder about if there is

问题 The getaddrinfo() function not only allows for client programs to efficiently find the correct data for creating a socket to a given host, it also allows for servers to bind to the correct socket - in theory. I just learned about that and started to play around with it via Python: from socket import * for i in getaddrinfo(None, 22, AF_UNSPEC, SOCK_STREAM, IPPROTO_IP, AI_PASSIVE): i yields (2, 1, 6, '', ('0.0.0.0', 22)) (10, 1, 6, '', ('::', 22, 0, 0)) what makes me wonder about if there is

问题 I have a list of links that I need to check before processing some data. Checking headers with http.get returns error: events.js:72 throw er; // Unhandled 'error' event ^ Error: getaddrinfo ENOTFOUND at errnoException (dns.js:37:11) I cannot handle this error, and exits the process. I tried res.on("error") and try..catch on http.get but nothing works. Below is the code snippet, and here is live example at runnable.com //This is OK getHeaders('http://google.com/404pag-that-does-not-exit'); /

问题 Beej's Simple Client example code iterates over all IP addresses returned from getaddrinfo(), until it can connect to the first one. See the code below. Is this always necessary, or is it OK to assume that we only have to try to connect to the first address returned by getaddrinfo()? memset(&hints, 0, sizeof hints); hints.ai_family = AF_UNSPEC; hints.ai_socktype = SOCK_STREAM; if ((rv = getaddrinfo(argv[1], PORT, &hints, &servinfo)) != 0) { fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv

问题 I would like to create a TCP server application which lets the user choose the local address that is used in the bind call. The user may provide a textual representation of a host name or IP address, so I thought of using the getaddrinfo function to translate the textual representation into one or several sockaddr structs (performing name lookup if necessary). Now here's my problem: The getaddrinfo function does not seem to suit my needs, because it requires the AI_PASSIVE flag to be set in