#include < stdio.h>
#include < sys/socket.h>
#include < netinet/in.h>
#include < errno.h>
#include < netdb.h>
#include < signal.h>

int main(int argc, char **argv)
{
int probeport = 0;
struct hostent *host;
int err, i, net;
struct sockaddr_in sa;

if (argc != 2) {
printf("usage: %s hostname\n", argv[0]);
exit(1);
}
/* ɨÃè1¡«1024¶Ë¿Ú·¶Î§ */
for (i = 1; i < 1024; i++)
{
strncpy((char *)&sa, "", sizeof sa);
sa.sin_family = AF_INET;
if (isdigit(*argv[1])) /* Èç¹ûÊÇIPµØÖ· */
sa.sin_addr.s_addr = inet_addr(argv[1]);
else if ((host = gethostbyname(argv[1])) != 0) /* Èç¹ûÊÇÖ÷»úÃû£¬ÐèҪת»» */
strncpy((char *)&sa.sin_addr, (char *)host->h_addr, sizeof sa.sin_addr);
else {
herror(argv[1]);
exit(2);
}
sa.sin_port = htons(i);
/* ´´½¨socket±êʶ·û */
net = socket(AF_INET, SOCK_STREAM, 0);
if (net < 0) {
perror("\nsocket");
exit(2);
}
/* ÓëÄ¿µÄ·½Á¬½Ó */
err = connect(net, (struct sockaddr *) &sa, sizeof sa);
if (err < 0) {
printf("%s %-5d %s\r", argv[1], i, strerror(errno));
fflush(stdout);
} else {
/* Èç¹ûÁ¬½Ó³É¹¦£¬´òÓ¡Ö÷»úÃû£¨»òµØÖ·£©ºÍ³É¹¦Á¬½ÓµÄ¶Ë¿ÚºÅ*/
printf("%s %-5d accepted. \n", argv[1], i);
if (shutdown(net, 2) < 0) {
perror("\nshutdown");
exit(2);
}
}
/* ¹Ø±Õsocket±êʶ·û */
close(net);
}
printf(" \r");
fflush(stdout);
return (0);
}
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