How do you flush a socket in C?

[MunkeN]

Hey there!

Currently I'm working on a project that handles alot of sockets (this application is *NIX).

At the moment, I got this code:
char *failed = "Some info about the error, bla\r\nbla bla (aprx. 181 chars long)\r\n";
send(fd, failed, strlen(failed), 0);
fflush(fd);
if(close(fd) != 0)
addlog("Error closing socket [%d]: %s", errno, strerror(errno));

fd is a INT.

The error I get is:
[connections.c:237] (Thread 0) **READ_WILD**
>> fflush(fd);

Reading wild pointer: <argument 1>

Pointer: 0x00000009

Stack trace where the error occurred:
fflush() (interface)
new_connection() src/connections.c, 237

Which causes a SEGFAULT (but the client gets the error msg \o/).

Best regards,
Anton.

[RRick]

The problem is that you are treating an unix integer file descriptor (ufd) as a C style FILE pointer. As you found out, this doesn't work.

One option is to turn the ufd into a FILE handle (i.e. use fdopen) and then use the C style functions(fflush, fprint, etc). If you do this, then stay with the C routines exclusively. See following for more info:http://www.uwo.ca/its/doc/courses/notes/socket/.

If you want to stay with the unix fds, then you need to use the ioctl function. Do a "man ioctl" on your system for more info. This will tell what parameters and system include files are needed.