libdill: Structured Concurrency for C


http_sendfield - sends HTTP field to the peer


#include <libdill.h>

int http_sendfield(
    int s,
    const char* name,
    const char* value,
    int64_t deadline);


WARNING: This is experimental functionality and the API may change in the future.

HTTP is an application-level protocol described in RFC 7230. This implementation handles only the request/response exchange. Whatever comes after that must be handled by a different protocol.

This function sends an HTTP field, i.e. a name/value pair, to the peer. For example, if name is Host and resource is the line sent will look like this:


After sending the last field of HTTP request don't forget to call hdone on the socket. It will send an empty line to the server to let it know that the request is finished and it should start processing it.

s: HTTP socket handle.

name: Name of the field.

value: Value of the field.

deadline: A point in time when the operation should time out, in milliseconds. Use the now function to get your current point in time. 0 means immediate timeout, i.e., perform the operation if possible or return without blocking if not. -1 means no deadline, i.e., the call will block forever if the operation cannot be performed.

This function is not available if libdill is compiled with --disable-sockets option.


In case of success the function returns 0. In case of error it returns -1 and sets errno to one of the values below.



int s = tcp_connect(&addr, -1);
s = http_attach(s);
http_sendrequest(s, "GET", "/", -1);
http_sendfield(s, "Host", "", -1);
hdone(s, -1);
char reason[256];
http_recvstatus(s, reason, sizeof(reason), -1);
while(1) {
    char name[256];
    char value[256];
    int rc = http_recvfield(s, name, sizeof(name), value, sizeof(value), -1);
    if(rc == -1 && errno == EPIPE) break;
s = http_detach(s, -1);


http_attach(3) http_attach_mem(3) http_detach(3) http_recvfield(3) http_recvrequest(3) http_recvstatus(3) http_sendrequest(3) http_sendstatus(3) now(3)