This is a quick example of a simple HTTP client program using the network-socket API that is provided as a part of mbed-os. The program brings up an underlying network interface, and uses it to perform an HTTP transaction over a TCPSocket.
main.cpp
- Committer:
- mbed_official
- Date:
- 2018-11-06
- Revision:
- 65:4b1f1da55e6e
- Parent:
- 64:a3dc04daaa2a
- Child:
- 72:47ae7d8d7321
File content as of revision 65:4b1f1da55e6e:
#include "mbed.h" // Network interface NetworkInterface *net; // Socket demo int main() { int remaining; int rcount; char *p; char *buffer = new char[256]; nsapi_size_or_error_t result; // Bring up the ethernet interface printf("Mbed OS Socket example\n"); #ifdef MBED_MAJOR_VERSION printf("Mbed OS version: %d.%d.%d\n\n", MBED_MAJOR_VERSION, MBED_MINOR_VERSION, MBED_PATCH_VERSION); #endif net = NetworkInterface::get_default_instance(); if (!net) { printf("Error! No network inteface found.\n"); return 0; } result = net->connect(); if (result != 0) { printf("Error! net->connect() returned: %d\n", result); return result; } // Show the network address const char *ip = net->get_ip_address(); const char *netmask = net->get_netmask(); const char *gateway = net->get_gateway(); printf("IP address: %s\n", ip ? ip : "None"); printf("Netmask: %s\n", netmask ? netmask : "None"); printf("Gateway: %s\n", gateway ? gateway : "None"); // Open a socket on the network interface, and create a TCP connection to api.ipify.org TCPSocket socket; // Send a simple http request char sbuffer[] = "GET / HTTP/1.1\r\nHost: api.ipify.org\r\nConnection: close\r\n\r\n"; nsapi_size_t size = strlen(sbuffer); result = socket.open(net); if (result != 0) { printf("Error! socket.open() returned: %d\n", result); } result = socket.connect("api.ipify.org", 80); if (result != 0) { printf("Error! socket.connect() returned: %d\n", result); goto DISCONNECT; } // Loop until whole request sent while(size) { result = socket.send(sbuffer+result, size); if (result < 0) { printf("Error! socket.send() returned: %d\n", result); goto DISCONNECT; } size -= result; printf("sent %d [%.*s]\n", result, strstr(sbuffer, "\r\n")-sbuffer, sbuffer); } // Receieve an HTTP response and print out the response line remaining = 256; rcount = 0; p = buffer; while (0 < (result = socket.recv(p, remaining))) { p += result; rcount += result; remaining -= result; } if (result < 0) { printf("Error! socket.recv() returned: %d\n", result); goto DISCONNECT; } // the HTTP response code printf("recv %d [%.*s]\n", rcount, strstr(buffer, "\r\n")-buffer, buffer); // The api.ipify.org service also gives us the device's external IP address p = strstr(buffer, "\r\n\r\n")+4; printf("External IP address: %.*s\n", rcount-(p-buffer), p); delete[] buffer; DISCONNECT: // Close the socket to return its memory and bring down the network interface socket.close(); // Bring down the ethernet interface net->disconnect(); printf("Done\n"); }