63.当当网txt数据按行切割与合并

• 获取文件有多少行

   //获取文件有多少行
   int getN(char *path)
   {
       FILE *pf = fopen(path, "r");
       if (pf==NULL)
       {
           return -;
       }
       else
       {
           int i = ;
           while (!feof(pf))
           {
               char str[] = {  };
               fgets(str, , pf);
               i++;
           }
           fclose(pf);
           return i;
       }
   }

• 宏定义行数

   //数据的行数
   #define N 13180820

• 文件按行切割

   //文件切割
   void space(char *path, int num)
   {
       char ** pathes = malloc(sizeof(char*)*num);
       for (int i = ; i < num;i++)
       {
           pathes[i] = malloc(sizeof(char) * );
           //格式化处理文件名
           sprintf(pathes[i], "dangdangwang%d.txt", i + );
       }
   
       //打开文件
       FILE *pf = fopen(path, "r");
   
       if (pf == NULL)
       {
           return -;
       }
       else
       {
           //如果能被整除
           if (N%num == )
           {
               for (int i = ; i <  num;i++)
               {
                   //写入文件
                   FILE *pfw = fopen(pathes[i], "w");
                   for (int j = ; j < N / num; j++)
                   {
                       char str[] = {  };
                       //读取一行写入一行
                       fgets(str, , pf);
                       fputs(str, pfw);
                   }
                   fclose(pfw);
               }
           }
           else
           {
               for (int i = ; i < num - ; i++)
               {
                   //写入文件
                   FILE *pfw = fopen(pathes[i], "w");
                   //处理前面n-1个
                   for (int j = ; j < N / (num-); j++)
                   {
                       char str[] = {  };
                       //读取一行写入一行
                       fgets(str, , pf);
                       fputs(str, pfw);
                   }
                   fclose(pfw);
   
               }
   
               {
                   //处理剩下的
                   //写入
                   FILE *pfw = fopen(pathes[num-], "w");
                   for (int j = ; j < N %(num-); j++)
                   {
                       char str[] = {  };
                       //读取一行写入一行
                       fgets(str, , pf);
                       fputs(str, pfw);
                   }
                   fclose(pfw);
               }
           }
           fclose(pf);
       }
   }

• 文件合并

   //合并文件
   void merge(char *newpath,int n)
   {
       char ** pathes = malloc(sizeof(char*)*n);
       for (int i = ; i < n; i++)
       {
           pathes[i] = malloc(sizeof(char) * );
           sprintf(pathes[i], "dangdangwang%d.txt", i + );
       }
   
       //写入文件
       FILE *pf = fopen(newpath, "w");
       if (pf == NULL)
       {
           return -;
       }
       else
       {
           //依次读取每个文件
           for (int i = ; i < n;i++)
           {
               FILE *pfr = fopen(pathes[i], "r");
   
               while (!feof(pfr))
               {
                   char str[] = {  };
                   //读取一行写入一行
                   fgets(str, , pfr);
                   fputs(str, pf);
               }
               fclose(pfr);
           }
           fclose(pf);
       }
   }

• 测试函数

   void main()
   {
       //int num = getN(path);
       //printf("%d", num);获取行数
       int  num;
       scanf("%d", &num);
   
       //分割
       space(path, num);
       //合并
       merge(newpath, num);
   
       system("pause");
   }

完整代码:

 #define  _CRT_SECURE_NO_WARNINGS
 #include <stdio.h>
 #include <stdlib.h>
 char *path = "dangdangwang.txt";
 char *newpath = "dangdangwangN.txt";
 
 //数据的行数
 #define N 13180820
 
 //获取文件有多少行
 int getN(char *path)
 {
     FILE *pf = fopen(path, "r");
     if (pf==NULL)
     {
         return -;
     }
     else
     {
         int i = ;
         while (!feof(pf))
         {
             char str[] = {  };
             fgets(str, , pf);
             i++;
         }
         fclose(pf);
         return i;
     }
 }
 
 //文件切割
 void space(char *path, int num)
 {
     char ** pathes = malloc(sizeof(char*)*num);
     for (int i = ; i < num;i++)
     {
         pathes[i] = malloc(sizeof(char) * );
         //格式化处理文件名
         sprintf(pathes[i], "dangdangwang%d.txt", i + );
     }
 
     //打开文件
     FILE *pf = fopen(path, "r");
 
     if (pf == NULL)
     {
         return -;
     }
     else
     {
         //如果能被整除
         if (N%num == )
         {
             for (int i = ; i <  num;i++)
             {
                 //写入文件
                 FILE *pfw = fopen(pathes[i], "w");
                 for (int j = ; j < N / num; j++)
                 {
                     char str[] = {  };
                     //读取一行写入一行
                     fgets(str, , pf);
                     fputs(str, pfw);
                 }
                 fclose(pfw);
             }
         }
         else
         {
             for (int i = ; i < num - ; i++)
             {
                 //写入文件
                 FILE *pfw = fopen(pathes[i], "w");
                 //处理前面n-1个
                 for (int j = ; j < N / (num-); j++)
                 {
                     char str[] = {  };
                     //读取一行写入一行
                     fgets(str, , pf);
                     fputs(str, pfw);
                 }
                 fclose(pfw);
 
             }
 
             {
                 //处理剩下的
                 //写入
                 FILE *pfw = fopen(pathes[num-], "w");
                 for (int j = ; j < N %(num-); j++)
                 {
                     char str[] = {  };
                     //读取一行写入一行
                     fgets(str, , pf);
                     fputs(str, pfw);
                 }
                 fclose(pfw);
             }
         }
         fclose(pf);
     }
 }
 
 //合并文件
 void merge(char *newpath,int n)
 {
     char ** pathes = malloc(sizeof(char*)*n);
     for (int i = ; i < n; i++)
     {
         pathes[i] = malloc(sizeof(char) * );
         sprintf(pathes[i], "dangdangwang%d.txt", i + );
     }
 
     //写入文件
     FILE *pf = fopen(newpath, "w");
     if (pf == NULL)
     {
         return -;
     }
     else
     {
         //依次读取每个文件
         for (int i = ; i < n;i++)
         {
             FILE *pfr = fopen(pathes[i], "r");
 
             while (!feof(pfr))
             {
                 char str[] = {  };
                 //读取一行写入一行
                 fgets(str, , pfr);
                 fputs(str, pf);
             }
             fclose(pfr);
         }
         fclose(pf);
     }
 }
 
 void main()
 {
     //int num = getN(path);
     //printf("%d", num);获取行数
     int  num;
     scanf("%d", &num);
 
     //分割
     space(path, num);
     //合并
     merge(newpath, num);
 
     system("pause");
 }