在C语言中，如何将文本文件的不同行保存到不同的变量

如何将文本文件中的不同行保存到不同数据类型的不同变量中；所有这些变量组成了一个结构（在我的示例中是一个包含以下内容的flight结构）

我想通过文本文件添加的信息示例如下

111
NYC
Monday

我显然想把单词NYC和Monday保存到一个char数组中，但我想把111保存到一个整数变量中

到目前为止我有

while (fscanf(flightInfo, "%s", tempName) != EOF)
{
     fscanf(flightInfo, "%d\n", &tempNum);
     flight.flightNumber = tempNum;
     fscanf(flightInfo, "%s\n", tempName);
     strcpy(flight.desination, tempName);
     fscanf(flightInfo, "%s\n", tempName)
     strcpy(flight.departDay, tempName);
}

---

假设flightInfo是指向文件名的指针，tempNum是一个整数，tempName是一个字符数组

听起来你的思路是对的

像这样的东西怎么样：

#define MAX_FLIGHTS 100
...
struct Flight flights[MAX_FLIGHTS ];
int n_flights = 0;
...
while (!feof(fp) && (n_flights < MAX_FLIGHTS-1))
{
     if (fscanf(fp, "%d\n", &flights[n_flights].flightNum) != 1)
        error_handler();
     if (fscanf(fp, "%29s\n", flights[n_flights].destination) != 1)
        error_handler();
     if (fscanf(fp, "%14s\n", flights[n_flights].departDay) != 1)
        error_handler();
     ++n_flights;
}
...

#定义最多100个航班
...
结构航班[最大航班]；
国际n_航班=0；
...
而（！feof（fp）和&（n_航班

增编： 根据Chux的建议，我修改了代码，通过将scanf max string length设置为29（比char[30]缓冲区大小小1），来减少潜在的缓冲区溢出

以下是更详细的解释：

---

您必须回答的第一个问题是：让人们或在其他平台上阅读文件有多重要

如果没有那么重要，那么我建议使用

fwrite（）

和

fread（）

进行序列化。这更容易为每个记录编写代码，并且只要结构大小相同，就允许O（1）访问文件中的任何记录

如果您确实希望将它们存储为单独的行，那么从文件中读入行的最佳方法是使用

fgets（）

伪代码如下：

typedef struct flight {
  int flightNum;
  char desination[30];
  char departDay[15];
} flight;

typedef struct flightSet {
  flight *flights;
  size_t n; /* number of flights */
  size_t nAlloc; /* number of flights you have space for */
} flightSet;

#define FLIGHTSET_INIT_SIZE 16
#define MAX_LINE_LENGTH 128
#define FILENAME "file.txt"

// Create a new flightSet, calling it F
// Allocate FLIGHTSET_INIT_ALLOC number of flight structures for F->flights
// Set F->n to 0
// Set F->nAlloc to FLIGHTSET_INIT_ALLOC

/* Set up other variables */
size_t i = 0;                       // iterator */
char buffer[MAX_LINE_LENGTH];   // for reading with fgets() */
flights *temp;                  // for realloc()ing when we have more flights to read
                            // after reaching nAlloc flights
char *endptr;                   // for using strtol() to get a number from buffer
FILE *fp;                       // for reading from the file

// Open FILENAME with fp for reading

//MAIN LOOP
  // If i == F->nAlloc, use realloc() to double the allocation of F->flights
  // If successful, double F->nAlloc

  if (fgets(buffer, MAX_LINE_LENGTH, fp) == NULL) {
      // End of file
      // Use break to get out of the main loop
  }

  F->flights[i]->flightNum = (int)strtol(buffer, &endptr, 10);
  if (endptr == buffer) {
    // The first invalid character that can't be converted to a number is at the very beginning
    // of the buffer, so this is not a valid numerical character and your data file is corrupt
    // Print out an error message
    break; 
  }

  if (fgets(buffer, MAX_LINE_LENGTH, fp) == NULL) {
      // End of file when expecting new line; file format error
      // Use break to get out of the main loop
  } else {
     F->flights[i]->destination = strdup(buffer);  // If your system has strdup()
     // Check for memory allocation
  }

  if (fgets(buffer, MAX_LINE_LENGTH, fp) == NULL) {
      // End of file when expecting new line; file format error
      // Use break to get out of the main loop
  } else {
     F->flights[i]->departDay = strdup(buffer);  // If your system has strdup()
     // Check for memory allocation
  }

  // If you've gotten here so far without errors, great!
  //    Increment F->n to reflect the number of successful records we have in F.
  //    Increment i, the loop iterator

//Final cleanup.  Should include closing the file, and freeing any allocated
//memory that didn't end up in a valid record. 

@约书亚-这不是个坏主意；使用并不是本质上的邪恶。我只是想尽可能地接近您的原始代码。请让我知道，如果你想让我更新我的例子；如果您还有任何问题，请告知我们。建议使用

fscanf（fp，%29s\n），航班[n\u航班]。目的地）

而不是

fscanf（fp，%s\n，航班[n\u航班]。目的地）

typedef struct flight {
  int flightNum;
  char desination[30];
  char departDay[15];
} flight;

typedef struct flightSet {
  flight *flights;
  size_t n; /* number of flights */
  size_t nAlloc; /* number of flights you have space for */
} flightSet;

#define FLIGHTSET_INIT_SIZE 16
#define MAX_LINE_LENGTH 128
#define FILENAME "file.txt"

// Create a new flightSet, calling it F
// Allocate FLIGHTSET_INIT_ALLOC number of flight structures for F->flights
// Set F->n to 0
// Set F->nAlloc to FLIGHTSET_INIT_ALLOC

/* Set up other variables */
size_t i = 0;                       // iterator */
char buffer[MAX_LINE_LENGTH];   // for reading with fgets() */
flights *temp;                  // for realloc()ing when we have more flights to read
                            // after reaching nAlloc flights
char *endptr;                   // for using strtol() to get a number from buffer
FILE *fp;                       // for reading from the file

// Open FILENAME with fp for reading

//MAIN LOOP
  // If i == F->nAlloc, use realloc() to double the allocation of F->flights
  // If successful, double F->nAlloc

  if (fgets(buffer, MAX_LINE_LENGTH, fp) == NULL) {
      // End of file
      // Use break to get out of the main loop
  }

  F->flights[i]->flightNum = (int)strtol(buffer, &endptr, 10);
  if (endptr == buffer) {
    // The first invalid character that can't be converted to a number is at the very beginning
    // of the buffer, so this is not a valid numerical character and your data file is corrupt
    // Print out an error message
    break; 
  }

  if (fgets(buffer, MAX_LINE_LENGTH, fp) == NULL) {
      // End of file when expecting new line; file format error
      // Use break to get out of the main loop
  } else {
     F->flights[i]->destination = strdup(buffer);  // If your system has strdup()
     // Check for memory allocation
  }

  if (fgets(buffer, MAX_LINE_LENGTH, fp) == NULL) {
      // End of file when expecting new line; file format error
      // Use break to get out of the main loop
  } else {
     F->flights[i]->departDay = strdup(buffer);  // If your system has strdup()
     // Check for memory allocation
  }

  // If you've gotten here so far without errors, great!
  //    Increment F->n to reflect the number of successful records we have in F.
  //    Increment i, the loop iterator

//Final cleanup.  Should include closing the file, and freeing any allocated
//memory that didn't end up in a valid record.