C程序合並文件找不到EOF，陷入無限循環！

Question

我在嘗試運行我正在開發的程序時遇到一些問題...要求說我不允許使用排序功能...我自己做了一些事情...等等。

程序幾乎可以編譯但在執行后會掛起...我猜它陷入了無限循環...但是我似乎找不到它... :(

該程序讀取已最小排序到最大排序的數據文件，並將它們合並（排序）為第三個.txt文件...

Data1.txt和Data2.txt這兩個文件包含：

數據1.txt

2
2
2
2

Data2.txt

1
3
5
7
9

組合

#include <stdio.h>
#include <stdlib.h>


void sortData(FILE *fpData1, FILE *fpData2)
{

 int n, m; 
 FILE *fpMerge;


 fpMerge = fopen("Merge.txt", "w+");


 fscanf(fpData2, "%i", &n);
 fscanf(fpData1, "%i", &m);
 while(n != EOF || m != EOF)
 {

  if(n == EOF)
  {
   fscanf(fpData1, "%i", &m);

   while(m != EOF)
   {

    fprintf(fpMerge, "%i\n", m);
    fscanf(fpData1, "%i", &m);
   }
  }
  if(m == EOF)
  {
   fscanf(fpData2, "%i", &n);

   while(n != EOF)
   {

    fprintf(fpMerge, "%i\n", n);
    fscanf(fpData2, "%i", &n);
   }

  }

  if(n < m)
  {
   fprintf(fpMerge, "%i\n", n);
   fscanf(fpData2, "%i", &n);
  }
  if(n > m)
  {
   fprintf(fpMerge, "%i\n", m);
   fscanf(fpData1, "%i", &m);
  }
  if(n == m)
  {
   fprintf(fpMerge, "%i\n", n); 
   fprintf(fpMerge, "%i\n", m);
   fscanf(fpData2, "%i", &n);
   fscanf(fpData1, "%i", &m);

  }
 }

 fclose(fpMerge);
}

int main (void)
{
 FILE *fpData1;
 FILE *fpData2;


 fpData1 = fopen("Data1.txt", "r");
 if(fpData1 == NULL)
 {
  printf("There was an error opening the file...program terminating..\n");
  exit(1);
 }

 fpData2 = fopen("Data2.txt", "r");
 if(fpData2 == NULL)
 {
  printf("There was an error opening the file...program terminating..\n");
  exit(1);
 }



 sortData(fpData1, fpData2);


 fclose(fpData1);
 fclose(fpData2); 

 return 0;
}

Answer 1

您不想比較n != EOF ，而是比較fscanf的返回值：

int count_1;
count_1 = fscanf(fpData1, "%i", &m);
if (count_1 == EOF) // EOF (or error)
{
  // ...
}

fscanf還將在錯誤時返回EOF 。 如果需要區分EOF和錯誤條件，請使用ferror(fpData1) ，然后查找錯誤代碼（存儲在errno ）。

Answer 2

您對EOF的測試不太正確

void sortData(FILE *fpData1, FILE *fpData2)
{
    int data1;
    int data2; 
    FILE *fpMerge;

    fpMerge = fopen("Merge.txt", "w+");
    fscanf(fpData1, "%i", &data1);
    fscanf(fpData2, "%i", &data2);

    // While one file still has data        
    while(!feof(fpData1) && !feof(fpData2))
    {
        // Choose 1 file to test
        // Read from that file and put into merge file until either we
        // run out of data or the condition fails.
        if(data1 < data2)
        {
            do {fprintf(fpMerge, "%i\n", data1);}
            while ((fscanf(fpData1, "%i", &data1) != 0) && (data1 <= data2));
        }
        else
        {
            do {fprintf(fpMerge, "%i\n", data2);}
            while ((fscanf(fpData2, "%i", &data2) != 0) && (data2 <= data1));
        }
        // NOTE: if fscanf() returns 0 it has failed to read (EOF)
    }
    // One of the files has reached the EOF
    // Dump the other file.
    while(fscanf(fpData1, "%i", &data1) != 0) {fprintf(fpMerge, "%i\n", data1);}
    while(fscanf(fpData2, "%i", &data2) != 0) {fprintf(fpMerge, "%i\n", data2);}
}

Answer 3

EOF不是字符。
EOF不是整數。
任何文件都不會包含EOF （ char或int ）。

EOF是一個條件。
文件要么處於那種狀態，要么（通常）沒有。

您應該檢查fscanf()的返回值以檢測EOF或其他問題。