Linux C语言写的超级简单port扫描器

 这个本来曾经也写过的，今天无聊复习下 再写一遍。简单的一塌糊涂，写的不咋地大家见谅哦！有空再加强 嘿嘿！

#include <stdio.h><br />#include <stdlib.h><br />#include <sys/socket.h><br />#include <time.h><br />#include <sys/types.h><br />#include <netinet/in.h><br />#include <netdb.h><br />void msg()<br />{<br /> printf(“EP:scan ip startport endport/nEP:scan ip 127.0.0.1 20 2009/n”);<br />}<br />int main(int argc,char** argv)<br />{<br /> char *ip;<br /> int startport,endport,sockfd,i;<br /> struct sockaddr_in to;<br /> float costtime;<br /> clock_t start,end;<br /> if(4!=argc)<br /> {<br /> msg();<br /> return 0;<br /> }<br /> ip=argv[1];<br /> startport=atoi(argv[2]);<br /> endport=atoi(argv[3]);<br /> if(startport<1 || endport>65535 || endport<startport)<br /> {<br /> printf(“port范围出错/n”);<br /> return 0;<br /> }<br /> else<br /> printf(“IP:%s %d-%d/n”,ip,startport,endport);<br /> to.sin_family=AF_INET;<br /> to.sin_addr.s_addr=inet_addr(ip);<br /> start=clock();<br /> for(i=startport;i<=endport;i++)<br /> {<br /> sockfd=socket(AF_INET,SOCK_STREAM,0);<br /> to.sin_port=htons(i);<br /> if(connect(sockfd,(struct sockaddr *)&to,sizeof(struct sockaddr))==0)<br /> {<br /> printf(“%s %d/n”,ip,i);<br /> close(to);<br /> }<br /> }<br /> end=clock();<br /> costtime=(float)(end-start)/CLOCKS_PER_SEC;<br /> printf(“用时:%f秒/n”,costtime);<br /> return 0;<br />}