在C中，如何计算char缓冲服务器中收到的数据？ 例如，客户端发送单个消息“1 2 3”，服务器必须计算这些数据并发送到客户端“3”，这是读取数据的数字。
这是客户：
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
int main(int argc, char *argv[]) {
int simpleSocket = 0;
int simplePort = 0;
int returnStatus= 0;
char buffsend[256];
char buffrecv[256];
char buff[256];
int i, n, length;
struct sockaddr_in simpleServer;
if (3 != argc) {
fprintf(stderr, "Usage: %s <server> <port>\n", argv[0]);
exit(1);
}
/* create a streaming socket */
simpleSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (simpleSocket == -1) {
fprintf(stderr, "Could not create a socket!\n");
exit(1);
}
else {
fprintf(stderr, "Socket created!\n");
}
/* retrieve the port number for connecting */
simplePort = atoi(argv[2]);
/* setup the address structure */
/* use the IP address sent as an argument for the server address */
//bzero(&simpleServer, sizeof(simpleServer));
memset(&simpleServer, '\0', sizeof(simpleServer));
simpleServer.sin_family = AF_INET;
//inet_addr(argv[2], &simpleServer.sin_addr.s_addr);
simpleServer.sin_addr.s_addr=inet_addr(argv[1]);
simpleServer.sin_port = htons(simplePort);
/* connect to the address and port with our socket */
returnStatus = connect(simpleSocket, (struct sockaddr *)&simpleServer, sizeof(simpleServer));
if (returnStatus == 0) {
fprintf(stderr, "Connect successful!\n");
}
else {
fprintf(stderr, "Could not connect to address!\n");
close(simpleSocket);
exit(1);
}
/* get the message from the server */
do {
printf("insert num of data or terminate ('0'): ");
fgets(buffsend,256,stdin);
n=atoi(buffsend);
if(n>6) {
printf("Error\n");
}
else {
length=strlen(buffsend);
for(i=0;i<n;i++) {
printf("insert number: ");
length=strlen(buffsend);
buffsend[length-1]=' ';
fgets(buffsend+length,256-length,stdin); }
printf("\n");
write(simpleSocket, buffsend, strlen(buffsend));
}
} while((n!=0) && (n>0));
close(simpleSocket);
return 0;
}
这是服务器：
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
int main(int argc, char *argv[]) {
int simpleSocket = 0;
int simplePort = 0;
int returnStatus = 0;
char buff[256];
char message[256];
int n, i, length, conta=0;
int media=0;
int varianza=0;
struct sockaddr_in simpleServer;
if (2 != argc) {
fprintf(stderr, "Usage: %s <port>\n", argv[0]);
exit(1);
}
simpleSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (simpleSocket == -1) {
fprintf(stderr, "Could not create a socket!\n");
exit(1);
}
else {
fprintf(stderr, "Socket created!\n");
}
/* retrieve the port number for listening */
simplePort = atoi(argv[1]);
/* setup the address structure */
/* use INADDR_ANY to bind to all local addresses */
memset(&simpleServer, '\0', sizeof(simpleServer));
simpleServer.sin_family = AF_INET;
simpleServer.sin_addr.s_addr = htonl(INADDR_ANY);
simpleServer.sin_port = htons(simplePort);
/* bind to the address and port with our socket */
returnStatus = bind(simpleSocket,(struct sockaddr *)&simpleServer,sizeof(simpleServer));
if (returnStatus == 0) {
fprintf(stderr, "Bind completed!\n");
}
else {
fprintf(stderr, "Could not bind to address!\n");
close(simpleSocket);
exit(1);
}
/* lets listen on the socket for connections */
returnStatus = listen(simpleSocket, 5);
if (returnStatus == -1) {
fprintf(stderr, "Cannot listen on socket!\n");
close(simpleSocket);
exit(1);
}
while (1)
{
struct sockaddr_in clientName = { 0 };
int simpleChildSocket = 0;
int clientNameLength = sizeof(clientName);
/* wait here */
simpleChildSocket = accept(simpleSocket,(struct sockaddr *)&clientName, &clientNameLength);
if (simpleChildSocket == -1) {
fprintf(stderr, "Cannot accept connections!\n");
close(simpleSocket);
exit(1);
}
/* handle the new connection request */
/* write out our message to the client */
while(read(simpleChildSocket, buff, 256)) {
printf("Data received: %s\n", buff);
bzero(buff, 256);
}
close(simpleChildSocket);
}
close(simpleSocket);
return 0;
}
在服务器部分，我想计算收到的数据。
答案 0 :(得分：0)
while(read(simpleChildSocket, buff, 256)) {
read函数返回从流中读取的字节数。你应该将它存储在某个地方，以便以后可以访问它。
通常，您有两种方法可以判断缓冲区中有多少字节：
1）只需将字节数存储在一个单独的整数中。
2）如果您的数据是文本字符串，请使用零字节终止文本字符串，然后在需要知道其长度时调用strlen。
答案 1 :(得分：-1)
我不知道我是否得到了它！
如果我明白了，你是否发送数据大小和空格字符数据？
示例：“3 123” 3 =长度，123 =数据
//server side
int received;
/*while(read(simpleChildSocket, buff, 256))*/
/*Make sure received>0 as well warned David
Schwartz*/
do{
received = read(simpleChildSocket, buff, 256);
if ( received > 0 )
printf("Data received: %s\n", buff);
else if ( received == 0 )
{
printf("Connection closed\n");
break;
}
else
{
printf("recv failed -1\n");
break;
}
/*int receved=strlen(buff);*/
char bufftmp[256]={0};
/*Loop through the buffer until you find space*/
for(int k=0;k<received;k++)
{
bufftmp[k]=buff[k];
if(buff[k]==' ')/*is equal space?*/
{
bufftmp[k]='\0';//make space null
int numpart=atoi(bufftmp);
printf("lenght of message is: %d\n",numpart);/*get only length*/
break;
}
}
bzero(buff, 256);
}while(received>0)