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 http_done 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);
http_done(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_done(3) http_recvfield(3) http_recvrequest(3) http_recvstatus(3) http_sendrequest(3) http_sendstatus(3) now(3)