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:
- 2018-06-18
- Revision:
- 48:f2739ac5cb01
- Parent:
- 47:08787ef063cb
- Child:
- 49:1923a727df5b
File content as of revision 48:f2739ac5cb01:
#include "mbed.h" #include "EthernetInterface.h" // Network interface EthernetInterface net; // Socket demo int main() { int remaining; int rcount; char *p; char *buffer = new char[256]; nsapi_size_or_error_t r; // Bring up the ethernet interface printf("Ethernet 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 r = net.connect(); if (r != 0) { printf("Error! net.connect() returned: %d\n", r); } // 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 mbed.org TCPSocket socket; r = socket.open(&net); if (r != 0) { printf("Error! socket.open() returned: %d\n", r); } r = socket.connect("api.ipify.org", 80); if (r != 0) { printf("Error! socket.connect() returned: %d\n", r); } // 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); // Loop until whole request send while(size) { r = socket.send(sbuffer+r, size); if (r < 0) { printf("Error! socket.connect() returned: %d\n", r); goto disconnect; } size -= r; printf("sent %d [%.*s]\n", r, strstr(sbuffer, "\r\n")-sbuffer, sbuffer); } // Receieve an HTTP response and print out the response line remaining = 256; rcount = 0; p = buffer; while (0 < (r = socket.recv(p, remaining))) { p += r; rcount += r; remaining -= r; } if (r < 0) { printf("Error! socket.recv() returned: %d\n", r); goto disconnect; } 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"); }