socket利大忖准會參式寄極會弌極會

<貧匯准和匯准>

音揖CPU嶄?4忖准屁方1壓坪贋腎寂議贋刈圭塀頁音揖議。4忖准屁方1辛喘2序崙燕幣泌和?

00000000 00000000 00000000 00000001

嗤乂CPU參貧中議乏會贋刈欺坪贋?総翌匯乂CPU夸參宜會贋刈?泌和侭幣?

00000001 00000000 00000000 00000000

飛音深打宸乂祥辺窟方象氏窟伏諒籾?咀葎隠贋乏會議音揖吭龍彭斤俊辺方象議盾裂乏會匆音揖。

寄極會才弌極會

CPU?坪贋隠贋方象議圭塀嗤曾嶽?

寄極會?Big Endian??互了忖准贋慧欺詰了仇峽?互了忖准壓念?。
弌極會?Little Endian??互了忖准贋慧欺互了仇峽?詰了忖准壓念?。

叙鴇宙峰載佃盾瞥賠萱?音形栖心匯倖糞箭。邪譜壓 0x20 催蝕兵議仇峽嶄隠贋4忖准 int 侏方象 0x12345678?寄極會CPU隠贋圭塀泌和夕侭幣?

夕1?屁方 0x12345678 議寄極會忖准燕幣

斤噐寄極會?恷互了忖准 0x12 贋慧欺詰了仇峽?恷詰了忖准 0x78 贋慧欺互了仇峽。弌極會議隠贋圭塀泌和夕侭幣?

夕2?屁方 0x12345678 議弌極會忖准燕幣

音揖CPU隠贋才盾裂方象議圭塀音揖?麼送議Intel狼双CPU葎弌極會??弌極會狼由才寄極會狼由宥佚扮氏窟伏方象盾裂危列。咀緩壓窟僕方象念?勣繍方象廬算葎由匯議鯉塀——利大忖准會?Network Byte Order?。利大忖准會由匯葎寄極會。

麼字A枠委方象廬算撹寄極會壅序佩利大勧補?麼字B辺欺方象朔枠廬算葎徭失議鯉塀壅盾裂。

利大忖准會廬算痕方

壓ゞ聞喘bind()才connect()痕方〃匯准嶄讐盾阻 sockaddr_in 潤更悶?凪嶄祥喘欺阻利大忖准會廬算痕方?泌和侭幣?

//幹秀sockaddr_in潤更悶延楚
struct sockaddr_in serv_addr;
memset(&serv_addr, 0, sizeof(serv_addr)); //耽倖忖准脅喘0野割
serv_addr.sin_family = AF_INET; //聞喘IPv4仇峽
serv_addr.sin_addr.s_addr = inet_addr("127.0.0.1"); //醤悶議IP仇峽
serv_addr.sin_port = htons(1234); //極笥催

htons() 喘栖繍輝念麼字忖准會廬算葎利大忖准會?凪嶄h旗燕麼字?host?忖准會?n旗燕利大?network?忖准會?s旗燕short?htons 頁 h、to、n、s 議怏栽?辛參尖盾葎”繍short侏方象貫輝念麼字忖准會廬算葎利大忖准會“。

械需議利大忖准廬算痕方嗤?

htons()?host to network short?繍short窃侏方象貫麼字忖准會廬算葎利大忖准會。
ntohs()?network to host short?繍short窃侏方象貫利大忖准會廬算葎麼字忖准會。
htonl()?host to network long?繍long窃侏方象貫麼字忖准會廬算葎利大忖准會。
ntohl()?network to host long?繍long窃侏方象貫利大忖准會廬算葎麼字忖准會。

宥械?參s葎朔弸議痕方嶄?s旗燕2倖忖准short?咀緩喘噐極笥催廬算?參l葎朔弸議痕方嶄?l旗燕4倖忖准議long?咀緩喘噐IP仇峽廬算。

訟箭傍苧貧峰痕方議距喘狛殻?

#include <stdio.h>
#include <stdlib.h>
#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib")
int main(){
 unsigned short host_port = 0x1234, net_port;
 unsigned long host_addr = 0x12345678, net_addr;
 net_port = htons(host_port);
 net_addr = htonl(host_addr);
 printf("Host ordered port: %#x\n", host_port);
 printf("Network ordered port: %#x\n", net_port);
 printf("Host ordered address: %#lx\n", host_addr);
 printf("Network ordered address: %#lx\n", net_addr);
 system("pause");
 return 0;
}

塰佩潤惚?
Host ordered port: 0x1234
Network ordered port: 0x3412
Host ordered address: 0x12345678
Network ordered address: 0x78563412

総翌俶勣傍苧議頁?sockaddr_in 嶄隠贋IP仇峽議撹埀葎32了屁方?遇厘断母呂議頁泣蛍噴序崙燕幣隈?箭泌 127.0.0.1?万頁匯倖忖憲堪?咀緩葎阻蛍塘IP仇峽?俶勣繍忖憲堪廬算葎4忖准屁方。

inet_addr() 痕方辛參頼撹宸嶽廬算。inet_addr() 茅阻繍忖憲堪廬算葎32了屁方?揖扮珊序佩利大忖准會廬算。萩心和中議旗鷹?

#include <stdio.h>
#include <stdlib.h>
#include <WinSock2.h>
#pragma comment(lib, "ws2_32.lib")
int main(){
 char *addr1 = "1.2.3.4";
 char *addr2 = "1.2.3.256";
 unsigned long conv_addr = inet_addr(addr1);
 if(conv_addr == INADDR_NONE){
 puts("Error occured!");
 }else{
 printf("Network ordered integer addr: %#lx\n", conv_addr);
 }
 conv_addr = inet_addr(addr2);
 if(conv_addr == INADDR_NONE){
 puts("Error occured!");
 }else{
 printf("Network ordered integer addr: %#lx\n", conv_addr);
 }
 system("pause");
 return 0;
}

塰佩潤惚?
Network ordered integer addr: 0x4030201
Error occured!

貫塰佩潤惚辛參心竃?inet_addr() 音叙辛參委IP仇峽廬算葎32了屁方?珊辛參殊霞涙丼IP仇峽。

廣吭?葎 sockaddr_in 撹埀験峙扮俶勣?塋週惱?濵臗崕斟鰈Ĺ士ę璿舸崕斟鬘ii?┨? write()/send() 窟僕方象扮TCP亅咏氏徭強廬算葎利大忖准會?音俶勣壅距喘屢哘議痕方。

<貧匯准和匯准>

socket利大忖准會參式寄極會弌極會

寄極會才弌極會

利大忖准會廬算痕方

socket園殻