关于c:Linux网络开发必学教程30文件浏览交互涉及

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问题：浏览器与文件服务器如何交互？

浏览器与文件服务器的交互

  • 文件浏览

    • 点击列表中的文件夹 → 进入子文件夹（展现子文件夹列表）

  • 文件下载

    • 点击列表中的文件 → 下载指标文件

  • 错误处理

    • 向服务器发送谬误申请 → 浏览不存在的文件夹 / 下载不存在的文件

文件浏览交互实现

实现中的要害概念

  • 共享文件夹（root）

    • 服务端启动时指定的共享文件夹门路（服务零碎中的门路）

  • 申请门路（req）

    • 文件 / 文件夹 在服务端上绝对共享文件夹的门路

  • 绝对路径

    • AbsPath = root + "/" + req

根底函数定义

  • char *GetAbsPath(const char *relative, const char *root)

    • 拼接 root 和 relative, 返回绝对路径，返回值需开释（free）

  • int isDotPath(const char *path)

    • 判断 path 是否为非凡门路 “.” 或 “..”

  • int GetEntryCount(const char *path)

    • 返回 path 门路下的（文件 + 文件夹）总数

编程试验：根底函数实现 

static char *GetAbsPath(const char *relative, const char *root)
{int reLen = strlen(relative);
    int rootLen = strlen(root);
    char *ret = malloc(reLen + rootLen + 2);

    if (ret) {strcpy(ret, root);

        if ((relative[0] == '/') && (ret[rootLen-1] == '/')) ret[rootLen - 1] = 0;
        if ((relative[0] != '/') && (ret[rootLen-1] != '/')) strcat(ret, "/");

        strcat(ret, relative);   
    }

    return ret;
}

static int IsDotPath(const char *path)
{
    int ret = -1;

    if (path) {ret = (strcmp(path, ".") == 0) || (strcmp(path, "..") == 0);
    }

    return ret;
}

static int GetEntryCount(const char *path)
{
    int ret = -1;
    DIR *dirp = opendir(path);

    if (dirp != NULL) {
        struct dirent *dp = NULL;

        ret = 0;
        while ((dp = readdir(dirp)) != NULL) {if (!IsDotPath(dp->d_name)) {ret ++;}
        }
    }
    closedir(dirp);

    return ret;
}

要害数据结构定义 

enum {
    TypeAll = 0x00,
    TypeDir = 0x04,
    TypeFile = 0x08
};

typdef struct {
    const int length;
    RowInfo data[];}FileEntry;

typedef struct {char link[2048];
      char name[255];
      char type[32];
      char size[32];
      char time[32];
}RowInfo;

要害函数定义

  • int MakeEntryItem(RowInfo *item, struct dirent *dp, const char *ap, const char *req);

    • 依据 dp 所指向的 文件 或 文件夹 生成 RowInfo 数据结构，胜利返回 true, 失败返回 false

  • FileEntry *GetEntry(const char *req, const char *root, int type);

    • 获取 root/req 门路下 文件 和 文件夹 所对应的 RowInfo 数组，返回值需开释（free）

  • char *MakeHTML(const char *req, const char *root);

    • 创立 root/req 门路下 文件 和 文件夹 所形成的 HTML 页面，返回值需开释（free）

服务端实现设计

非凡页面设计

编程试验：文件浏览交互实现 


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <unistd.h>
#include <time.h>
#include "page.h"
#include "response.h"

enum {TypeAll = 0x00, TypeDir = 0x04, TypeFile = 0x08};

typedef struct 
{
    const int length;
    RowInfo data[];} FileEntry;

static char* GetAbsPath(const char* relative, const char* root)
{int reLen = strlen(relative);
    int rootLen = strlen(root);
    char* ret = malloc(reLen + rootLen + 2);
    
    if(ret) {strcpy(ret, root);
        
        if((relative[0] == '/') && (ret[rootLen-1] == '/') ) ret[rootLen-1] = 0;
        if((relative[0] != '/') && (ret[rootLen-1] != '/') ) strcat(ret, "/");
        
        strcat(ret, relative);
    }
    
    return ret;
}

static int IsDotPath(const char* path)
{
    int ret = -1;
    
    if(path) {ret = (strcmp(path, ".") == 0) || (strcmp(path, "..") == 0);
    }
    
    return ret;
}

static int GetEntryCount(const char* path)
{
    int ret = -1;
    DIR* dirp = opendir(path);
    
    if(dirp != NULL) {
        struct dirent* dp = NULL;
        
        ret = 0;
        
        while((dp = readdir(dirp)) != NULL ) {if( !IsDotPath(dp->d_name) ) {ret++;}
        }
    }
    
    closedir(dirp);
    
    return ret;
}

static void SortFileEntry(FileEntry* fe)
{RowInfo* temp = malloc(sizeof(*temp));
    
    if(fe && temp) {
        int i = 0;
        int j = 0;
        
        for(i=0; i<fe->length; i++) {
            int min = i;
            
            for(j=i; j<fe->length; j++) {if( strcmp(fe->data[min].name, fe->data[j].name) > 0 ) {min = j;}
            }
            
            *temp = fe->data[i];
            fe->data[i] = fe->data[min];
            fe->data[min] = *temp;
        }
    }
    
    free(temp);
}

static int MakeEntryItem(RowInfo* item, struct dirent* dp, const char* ap, const char* req)
{
    int ret = 0;
    char buf[32] = {0};
    struct stat sb = {0};
    char* path = GetAbsPath(dp->d_name, ap);
    
    if(path && (ret = (stat(path, &sb)) != -1) )
    {strcpy(item->link, req);
        (strcmp(req, "/") != 0) ? strcat(item->link, "/") : 0;
        strcat(item->link, dp->d_name);
        
        strcpy(item->name, dp->d_name);
        
        if(dp->d_type == TypeFile) {strcpy(item->type, "File");
            
            if(sb.st_size < 1024) {sprintf(buf, "%ld", sb.st_size);
                strcpy(item->size, buf);
                strcat(item->size, "Byte");
            }
            else if((sb.st_size / 1024) < 1024 ) {sprintf(buf, "%ld", sb.st_size/1024);
                strcpy(item->size, buf);
                strcat(item->size, "KB");
            }
            else {sprintf(buf, "%ld", sb.st_size/1024/1024);
                strcpy(item->size, buf);
                strcat(item->size, "MB");
            }
        }
        else {strcpy(item->type, "Folder");
            
            sprintf(buf, "%d", GetEntryCount(path));
            strcpy(item->size, buf);
            strcat(item->size, "Item");
        }
        
        strcpy(item->time, ctime(&sb.st_mtime));
    }
    
    free(path);
    
    return ret;
}

static FileEntry* GetEntry(const char* req, const char* root, int type)
{char* ap = GetAbsPath(req, root);
    DIR* dirp = NULL;
    FileEntry* ret = NULL;
    
    if(ap && (dirp = opendir(ap)) ) {
        const int STEP = 5;
        struct dirent* dp = NULL;
        int max = 0;
        int* pLen = NULL;
        
        ret = malloc(sizeof(*ret));
        
        if(ret) {pLen = (int*)&ret->length;
            *pLen = 0;
        }
        
        while(pLen && ((dp = readdir(dirp)) != NULL) ) {if( *pLen == max) {
                max = max + STEP;
                ret = realloc(ret, sizeof(*ret) + sizeof(RowInfo) * max);
                pLen = (int*)&ret->length;
            }
            
            if(ret && ((type == TypeAll) || (type == dp->d_type)) ) {if( !IsDotPath(dp->d_name) && MakeEntryItem(&ret->data[*pLen], dp, ap, req) )
                {*pLen = *pLen + 1;}
            }
        }
        
        SortFileEntry(ret);
    }
    
    free(ap);
    closedir(dirp);
    
    return ret;
}

static char* MakeHTML(const char* req, const char* root)
{
    char* ret = NULL;
    Table* table = CreateTable();
    
    if(table) {
        FileEntry* fe = NULL;
        char* ts = NULL;
        char* resp = NULL;
        RowInfo* back = NULL;
        int i = 0;
        
        if((strcmp(req, "/") != 0) && (back = calloc(1, sizeof(*back))) ) {i = strlen(req) - 1;
            
            strcpy(back->link, req);
            
            while(back->link[i] != '/' ) i--;
            
            i ? (back->link[i] = 0) : (back->link[i+1] = 0);
            
            strcpy(back->name, "./..");
            strcpy(back->type, "Back..");
            
            table = InsertRow(table, back);
        }
        
        free(back);
        
        fe = GetEntry(req, root, TypeDir);
        
        for(i=0; fe && (i<fe->length); i++) {table = InsertRow(table, &fe->data[i]);
        }
        
        free(fe);
        
        fe = GetEntry(req, root, TypeFile);
        
        for(i=0; fe && (i<fe->length); i++) {table = InsertRow(table, &fe->data[i]);
        }
        
        free(fe);
        
        ts = ToTableString(table);
        
        ret = ts ? ToPageString(req, ts) : NULL;
          
        free(ts);
    }
    
    FreeTable(table);
    
    return ret;
}

static int Response(TcpClient* client, const char* html)
{
    const char* HTTP_FORMAT =    "HTTP/1.1 200 OK\r\n"
                                 "Server:Test Http Server\r\n"
                                 "Content-Length:%d\r\n"
                                 "Content-Type:text/html\r\n"
                                 "Connection:close\r\n\r\n"
                                 "%s";
    int ret = 0;
                                 
    if(html) {char* resp = malloc(strlen(HTTP_FORMAT) + strlen(html) + 16);
        
        if(resp) {sprintf(resp, HTTP_FORMAT, strlen(html), html);
            
            ret = (TcpClient_SendRaw(client, resp, strlen(resp)) > 0);
        }
        
        free(resp);
    }
    
    return ret;
}

static int DirReqHandler(TcpClient* client, const char* req, const char* root)
{char* html = MakeHTML(req, root);
    int ret = Response(client, html);
    
    free(html);
    
    return ret;
}

int RequestHandler(TcpClient* client, const char* req, const char* root)
{
    int ret = 0;
    
    if(client && req && root) {ret = DirReqHandler(client, req, root);
    }
    
    return ret;
}

思考

favicon.ico 是什么？如何解决？

正文完
c
发表至： c#
2023-06-08
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