《Linux网络开发必学教程》29_动态创建交互页面

问题：如何创建浏览器中的文件展示页面？

再论前端页面

交互页面分析

• 静态部分

  • 表格，页面结构

• 动态部分

  • 文件浏览路径 (Path)
  • 文件列表（Table）

""
""
"    "
"    "
"    "
"    "
"    "
"    
DT4SW Http File Server
"
"    
"
"    
Path: %s
"
"    %s"
"    "
""

文件列表分析

• 静态

  • 表格标题行
  • 表格列表结构

• 动态部分

  • 表格行数据

"";
"    "
"        "
"    "
"        "
"    "
"
File Name
File Type
File Size
Modify Time
%s
%s
%s
%s
"

文件列表接口函数及数据结构

• Table *CreateTable();
• Table *InsertRow(Table *table, RowInfo *info);
• char *ToTableString(Table *table);
• void FreeTable(Table *table);

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

解决方案

• CreateTable()

  • 从堆空间创建表格标题行，并作为初始表格数据返回

• InsertRow(table, info)

  • 将 info 中的字符串进行表格行格式化，并添加到 table 末尾

• ToTableString(table)

  • 将 table 表格数据格式化为 HTML 字符串，并返回

表格动态创建关键代码

if (table && info) {
    char *t = table;
    int len = strlen(t);
    char *buf = malloc(strlen(ROW_FORMAT) + sizeof(*info));
    if (buf) {
        sprintf(buf, ROW_FORMAT, info->link, info->name, info->type, info->size, info->time);
        ret = realloc(t, len + strlen(buf) + 1);
        ret = ret ? (strcpy(ret + len, buf), ret) : t;
    } else {
        ret = t;
    }
    free(buf);
}

页面动态创建代码

char *ToPageString(const char *path, char *ts)
{
    char *ret = NULL;

    if (path && ts && (ret = malloc(strlen(PAGE_FORMAT) + strlen(path) + strlen(ts) + 1))) {
        sprintf(ret, PAGE_FORMAT, path, ts);
    }

    return ret;
}

编程实验：动态创建交互页面

main.c

#include
#include
#include
#include
#include 
#include 
#include 
#include 
#include 
#include 

#include "tcp_server.h"
#include "tcp_client.h" 
#include "utility.h"
#include "page.h"

int main(int argc, char *argv[])
{
    Table *t = CreateTable();
    RowInfo ri = {"aa", "bbb", "cccc", "ddddd", "eeeeee"};
    RowInfo rj = {"11", "222", "3333", "44444", "555555"};

    t = InsertRow(t, &ri);
    t = InsertRow(t, &rj);

    char *ts = ToTableString(t);
    char *page = ToPageString("test/path/folder", ts);

    printf("%s\n", page);

    free(page);
    free(ts);
    FreeTable(t);

    return 0;
}

page.h

#ifndef PAGE_H
#define PAGE_H

typedef void Table;

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

char* ToPageString(const char* path, const char* ts);
Table* CreateTable();
Table* InsertRow(Table* table, RowInfo* info);
char* ToTableString(Table* table);
void FreeTable(Table* table);

#endif  // PAGE_H

page.c

#include "page.h"

#include 
#include 
#include 

static const char* PAGE_FORMAT = ""
                                 ""
                                 "  "
                                 "    "
                                 "    "
                                 "  "
                                 "  "
                                 "    
DT4SW Http File Server
"
                                 "    
"
                                 "    
Path: %s
"
                                 "    %s"
                                 "  "
                                 "";

static const char* TABLE_BEGIN = "";
                                                                  
static const char* TABLE_TITLE = "  "
                                 "    "
                                 "  ";
                                
static const char* ROW_FORMAT =  ""
                                 "  "
                                 "";     
                                
static const char* TABLE_END =   "  "
                                 "
File Name
File Type
File Size
Modify Time
%s
%s
%s
%s
";  

char *ToPageString(const char *path, const char *ts)
{
    char *ret = NULL;

    if (path && ts && (ret = malloc(strlen(PAGE_FORMAT) + strlen(path) + strlen(ts) + 1))) {
        sprintf(ret, PAGE_FORMAT, path, ts);
    }

    return ret;
}

Table *CreateTable()
{
    const int TITLE_LEN = strlen(TABLE_TITLE);
    char *ret = malloc(TITLE_LEN + 1);

    if (ret) {
        strcpy(ret, TABLE_TITLE);
    }

    return ret;
}

char *ToTableString(Table *table)
{
    const int BEGIN_LEN = strlen(TABLE_BEGIN);
    const int END_LEN = strlen(TABLE_END);
    char *ret = NULL;

    if (table && (ret = malloc(strlen(table) + BEGIN_LEN + END_LEN + 1))) {
        strcpy(ret, TABLE_BEGIN);
        strcpy(ret + BEGIN_LEN, table);
        strcpy(ret  + BEGIN_LEN + strlen(table), TABLE_END);
    }

    return ret;
}

Table *InsertRow(Table *table, RowInfo *info)
{
    char *ret = NULL;

    if (table && info) {
        char *t = table;
        int len = strlen(t);
        char *buf = malloc(strlen(ROW_FORMAT) + sizeof(*info));
        if (buf) {
            sprintf(buf, ROW_FORMAT, info->link, info->name, info->type, info->size, info->time);
            ret = realloc(t, len + strlen(buf) + 1);
            ret = ret ? (strcpy(ret + len, buf), ret) : t;
        } else {
            ret = t;
        }
        free(buf);
    }

    return ret;
}

void FreeTable(Table *table)
{
    free(table);
}

输出

                  
DT4SW Http File Server
    
    
Path: test/path/folder
    
  
    
File Name
File Type
File Size
Modify Time
  
  
bbb
cccc
ddddd
eeeeee
  
222
3333
44444
555555
  
  

思考

浏览器于文件服务器如何交互？