/* count time functions */
static double mytime(void)
{
struct timeval tv;
if (gettimeofday(&tv, NULL) == -1)
return 0.0;

return (double)tv.tv_usec + (double)tv.tv_sec * 1000000;
}

static PyObject * /* returns object */
tcpping(PyObject *self, PyObject *args )
{
struct sockaddr_in addr;
struct hostent *hp;
double time;
char *host = NULL;
int fd;
int port, timeout;

if (!PyArg_ParseTuple(args, "sii", &host, &port, &timeout)) /* convert Python -> C */
return NULL; /* null=raise exception */

if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
return Py_BuildValue("d", -1.0); /* convert C -> Python */
}

bzero((char *)&addr, sizeof(addr));
if ((hp = gethostbyname(host)) == NULL) {
return Py_BuildValue("d", -2.0); /* convert C -> Python */
}
bcopy(hp->h_addr, &addr.sin_addr, hp->h_length);
addr.sin_family = AF_INET;
addr.sin_port = htons(port);

struct timeval tv;

tv.tv_sec = 0;
tv.tv_usec = timeout * 1000;

double stime = mytime();
if (connect(fd, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
return Py_BuildValue("d", -3.0); /* convert C -> Python */
}
fd_set read, write;
FD_ZERO(&read);
FD_ZERO(&write);

FD_SET(fd, &read);
FD_SET(fd, &write);

if (select(fd + 1, &read, &write, NULL, &tv) == 0) {
close(fd);
return Py_BuildValue("d", -4.0); /* convert C -> Python */
}

double etime = mytime();
time = etime - stime;
if (!FD_ISSET(fd, &read) && !FD_ISSET(fd, &write)) {
close(fd);
return Py_BuildValue("d", -4.0); /* convert C -> Python */
}
close(fd);
return Py_BuildValue("d", time/1000); /* convert C -> Python */
}

/* registration table */
static struct PyMethodDef portping_methods[] = {
{"tcpping", tcpping, METH_VARARGS}, /* method name, C func ptr, always-tuple */
{NULL, NULL} /* end of table marker */
};

/* module initializer */
void inittcpportping( ) /* called on first import */
{ /* name matters if loaded dynamically */
(void) Py_InitModule("tcpportping", portping_methods); /* mod name, table ptr */
}

编译成python模块
代码如下:

下面是python调用c模块的代码：
代码如下:

import tcpportping
import time

i = 0
while i < 5:
t = tcpportping.tcpping('www.baidu.com', 80, 1000)
if t < 0:
print "time out"
else:
print t
time.sleep(0.5)
i += 1