所以，我想创建一个具有不同操作的客户端服务器程序，例如，对文件夹（GET_ALL_INFO）中的所有文件进行上次修改，对一个文件夹（GET_FILE_INFO）进行修改，从服务器上删除文件（REMOVE_FILE）和服务器上的ADD_FILE，但是我有一个问题，因为每次在客户端输入ADD_FILE nameOfFile时都会检查，所以不检查它的分支。我使用socket来传输文件和所有信息。
在服务器中，如果未检查（strncmp（“ADD_FILE”....）:(为什么？
非常感谢你的帮助！
这是我的服务器代码：
#include <stdio.h>
#include <string.h> //strlen
#include <stdlib.h> //strlen
#include <sys/socket.h>
#include <arpa/inet.h> //inet_addr
#include <unistd.h> //write
#include <pthread.h> //for threading , link with lpthread
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
//the thread function
void *connection_handler(void *);
struct dirent_t {
ino_t d_ino; /* inode number */
off_t d_off; /* offset to the next dirent */
unsigned short d_reclen; /* length of this record */
unsigned char d_type; /* type of file */
char d_name[256]; /* filename */
};
int socket_desc , client_sock , c , *new_sock;
struct sockaddr_in server , client;
int main(int argc , char *argv[])
{
//Create socket
socket_desc = socket(AF_INET , SOCK_STREAM , 0);
if (socket_desc == -1)
{
printf("Could not create socket");
}
puts("Socket created");
//Prepare the sockaddr_in structure
server.sin_family = AF_INET;
server.sin_addr.s_addr = INADDR_ANY;
server.sin_port = htons( 8888 );
//Bind
if( bind(socket_desc,(struct sockaddr *)&server , sizeof(server)) < 0)
{
//print the error message
perror("bind failed. Error");
return 1;
}
puts("bind done");
//Listen
listen(socket_desc , 3);
//Accept and incoming connection
puts("Waiting for incoming connections...");
c = sizeof(struct sockaddr_in);
//Accept and incoming connection
puts("Waiting for incoming connections...");
c = sizeof(struct sockaddr_in);
while( (client_sock = accept(socket_desc, (struct sockaddr *)&client, (socklen_t*)&c)) )
{
puts("Connection accepted");
pthread_t sniffer_thread;
new_sock = malloc(1);
*new_sock = client_sock;
if( pthread_create( &sniffer_thread , NULL , connection_handler , (void*) new_sock) < 0)
{
perror("could not create thread");
return 1;
}
//Now join the thread , so that we dont terminate before the thread
//pthread_join( sniffer_thread , NULL);
puts("Handler assigned");
}
if (client_sock < 0)
{
perror("accept failed");
return 1;
}
return 0;
}
/*
* This will handle connection for each client
* */
void *connection_handler(void *socket_desc)
{
//Get the socket descriptor
int sock = *(int*)socket_desc;
int read_size;
char client_message[2000], path[2000];
int fd = 0, condfd = 0, b, tot;
char buff[1024];
//Receive a message from client
while( (read_size = recv(sock , client_message , 2000 , 0)) > 0 )
{
int i = 0, j =0;
if(strncmp(client_message, "GET_ALL_INFO ", 12) == 0)
{
for(i = 13; i < strlen(client_message); i++){
path[j] = client_message[i];
j++;
}
struct dirent_t *entry;
DIR *dir = opendir(path);
if (dir == NULL) {
return;
}
while ((entry = readdir(dir)) != NULL)
{
struct stat attrib;
stat(entry->d_name, &attrib);
char date[30];
strftime(date, 30, "%d-%m-%y", localtime(&(attrib.st_ctime)));
//Send the message back to client
write(sock , entry->d_name, strlen(entry->d_name));
write(sock, "\t\t\t", strlen("\t\t\t"));
write(sock, "last modified: ", strlen( "last modified: "));
write(sock, date, strlen(date));
date[0] = 0;
write(sock , "\n", strlen("\n"));
}
closedir(dir);
bzero(client_message, strlen(client_message));
bzero(path, strlen(path));
}
else if(strncmp(client_message, "GET_FILE_INFO ", 13) == 0)
{
for(i = 14; i < strlen(client_message); i++){
path[j] = client_message[i];
j++;
}
struct stat attrib;
stat(path, &attrib);
char date[30];
strftime(date, 30, "%d-%m-%y", localtime(&(attrib.st_ctime)));
//Send the message back to client
write(sock , path, strlen(path));
write(sock, "\t\t\t", strlen("\t\t\t"));
write(sock, "last modified: ", strlen("last modified: "));
write(sock, date, strlen(date));
date[0] = 0;
write(sock , "\n", strlen("\n"));
bzero(client_message, strlen(client_message));
bzero(path, strlen(path));
}
else if(strncmp(client_message, "REMOVE_FILE ", 11) == 0)
{
for(i = 12; i < strlen(client_message); i++){
path[j] = client_message[i];
j++;
}
int status;
status = remove(path);
if(status == 0)
{
write(sock, path, strlen(path));
write(sock, " file deleted successfuly.", strlen(" file deleted successfuly."));
bzero(client_message, strlen(client_message));
bzero(path, strlen(path));
}
else
{
write(sock, "Unable to delete the file!", strlen("Unable to delete the file!"));
bzero(client_message, strlen(client_message));
bzero(path, strlen(path));
}
}
else if(strncmp(client_message, "ADD_FILE ", 8) == 0)
{
for(i = 9; i < strlen(client_message); i++){
path[j] = client_message[i];
j++;
}
FILE* fp = fopen(path, "w");
tot = 0;
if(fp != NULL)
{
while( (b = recv(client_sock, buff, 1024, 0)) > 0)
{
tot += b;
fwrite(buff, 1, b, fp);
}
printf("Recieved byte: %d\n", tot);
if(b < 0)
perror("Receiving");
fclose(fp);
bzero(client_message, strlen(client_message));
bzero(path, strlen(path));
}
else
perror("File");
}
else
{
write(sock , client_message , strlen(client_message));
bzero(client_message, strlen(client_message));
bzero(path, strlen(path));
}
}
if(read_size == 0)
{
puts("Client disconnected");
fflush(stdout);
}
else if(read_size == -1)
{
perror("recv failed");
}
//Free the socket pointer
free(socket_desc);
return 0;
}
这是我的客户代码：
#include <stdio.h> //printf
#include <string.h> //strlen
#include <sys/socket.h> //socket
#include <arpa/inet.h> //inet_addr
int main(int argc , char *argv[])
{
int sock;
int b;
struct sockaddr_in server;
char message[1000] , server_reply[2000];
//Create socket
sock = socket(AF_INET , SOCK_STREAM , 0);
if (sock == -1)
{
printf("Could not create socket");
}
puts("Socket created");
server.sin_addr.s_addr = inet_addr("127.0.0.1");
server.sin_family = AF_INET;
server.sin_port = htons( 8888 );
//Connect to remote server
b = connect(sock , (struct sockaddr *)&server , sizeof(server));
if(b == -1)
{
perror("connect failed. Error");
return 1;
}
puts("Connected\n");
char file_name[2000];
char send_buffer[1024];
int i = 0, j = 0;
//keep communicating with server
while(1)
{
puts("Enter message : ");
gets(message);
if(strncmp(message, "ADD_FILE ", 8) == 0)
{
for(i = 9; i < strlen(message); i++){
file_name[j] = message[i];
j++;
}
FILE *fp = fopen(file_name, "r");
if(fp == NULL)
{
perror("File");
return 2;
}
while((b = fread(send_buffer, 1, sizeof(send_buffer), fp)) > 0)
{
send(sock, send_buffer, strlen(send_buffer), 0);
}
fclose(fp);
}
//Send some data
else if( send(sock , message , strlen(message), 0) < 0)
{
puts("Send failed");
return 1;
}
//Receive a reply from the server
if( recv(sock , server_reply , 2000 , 0) < 0)
{
puts("recv failed");
break;
}
puts("Server reply :");
puts(server_reply);
bzero(server_reply, strlen(server_reply));
}
close(sock);
return 0;
}
答案 0 :(得分：0)
您要问的问题是在客户端。在：
if(strncmp(message, "ADD_FILE ", 8) == 0)
{
...
}
else if ...
不发送消息，只发送文件。因此，服务器永远不会收到消息"ADD_FILE"。
在该部分代码中还存在另外两个问题：
j未重置为0。file_name未以'\0'终止。