c - 如何在 C 中获取文件的大小？

Question

可能重复：
如何确定 C 中文件的大小？

如何在 C 中获取文件的大小？我打开了一个用 C 编写的应用程序。我想知道大小，因为我想将加载文件的内容放入一个字符串中，我使用 malloc() 进行分配。只写 malloc(10000*sizeof(char)

Answer 1

您可以使用 fseek 和 ftell 函数：

FILE* f = fopen("try.txt","rb");
fseek(f, 0, SEEK_END);
printf("size of the file is %ld", ftell(f));

Answer 2

对于文件大小，stat、lstat 或 fstat 将是正确的选择。

请检查统计

Answer 3

    int Get_Size( string path )
{

FILE *pFile = NULL;

// get the file stream

fopen_s( &pFile, path.c_str(), "rb" );


// set the file pointer to end of file

fseek( pFile, 0, SEEK_END );

// get the file size

int Size = ftell( pFile );

// return the file pointer to begin of file if you want to read it

rewind( pFile );

// close stream and release buffer

fclose( pFile );

return Size;
}

更多答案cplusplus.com

Answer 4

您可以使用 fseek 将自己定位在文件的末尾，并为此使用 ftell()：

FILE *fd;
fd = fopen("filename.txt","rb");
fseek ( fd, 0 , SEEK_END );
int fileSize = ftell(fd);

filesize 将包含以字节为单位的大小。

格科德

Answer 5

我认为有一个标准的 C 函数，但我找不到它。

If your file size is limited, you can use the solution proposed by izomorphius.

If your file can be larger than 2GB then you can use the _filelengthi64 function (see http://msdn.microsoft.com/en-us/library/dfbc2kec(v=vs.80).aspx). Unfortunately, this is a Microsoft/Windows function so it's probably not available for other platforms (although you will probably find similar functions on other platforms).

EDIT: Look at afge2's answer for the standard C function. Unfortunately, I think this is still limited to 2GB.