在C语言中，我们使用文件（Files）来处理文件操作，我们使用类型为FILE的指针来操作文件。因此，FILE是一种数据类型。这被称为不透明数据类型，因为其实现是隐藏的。FILE的定义是系统特定的。以下是Ubuntu系统中FILE的定义：
FILE定义
struct _IO_FILE { int _flags; /* High-order word is _IO_MAGIC; rest is flags. */ #define _IO_file_flags _flags /* The following pointers correspond to the C++ streambuf protocol. */ /* Note: Tk uses the _IO_read_ptr and _IO_read_end fields directly. */ char* _IO_read_ptr; /* Current read pointer */ char* _IO_read_end; /* End of get area. */ char* _IO_read_base; /* Start of putback+get area. */ char* _IO_write_base; /* Start of put area. */ char* _IO_write_ptr; /* Current put pointer. */ char* _IO_write_end; /* End of put area. */ char* _IO_buf_base; /* Start of reserve area. */ char* _IO_buf_end; /* End of reserve area. */ /* The following fields are used to support backing up and undo. */ char *_IO_save_base; /* Pointer to start of non-current get area. */ char *_IO_backup_base; /* Pointer to first valid character of backup area */ char *_IO_save_end; /* Pointer to end of non-current get area. */ struct _IO_marker *_markers; struct _IO_FILE *_chain; int _fileno; #if 0 int _blksize; #else int _flags2; #endif _IO_off_t _old_offset; /* This used to be _offset but it's too small. */ #define __HAVE_COLUMN /* temporary */ /* 1+column number of pbase(); 0 is unknown. */ unsigned short _cur_column; signed char _vtable_offset; char _shortbuf[1]; /* char* _save_gptr; char* _save_egptr; */ _IO_lock_t *_lock; #ifdef _IO_USE_OLD_IO_FILE};struct _IO_FILE_complete{ struct _IO_FILE _file; #endif #if defined _G_IO_IO_FILE_VERSION && _G_IO_IO_FILE_VERSION == 0x20001 _IO_off64_t _offset; # if defined _LIBC || defined _GLIBCPP_USE_WCHAR_T /* Wide character stream stuff. */ struct _IO_codecvt *_codecvt; struct _IO_wide_data *_wide_data; struct _IO_FILE *_freeres_list; void *_freeres_buf; size_t _freeres_size; # else void *__pad1; void *__pad2; void *__pad3; void *__pad4; size_t __pad5; # endif int _mode; /* Make sure we don't get into trouble again. */ char _unused2[15 * sizeof (int) - 4 * sizeof (void *) - sizeof (size_t)]; #endif};
现在让我们看一个使用FILE的例子。
Text file (/tmp/test.txt):Thisis testing for fprintf...This is testing for fputs...
Example
的中文翻译为：
示例
#include main() { FILE *fp; char buff[255]; fp = fopen("/tmp/test.txt", "r"); fscanf(fp, "%s", buff); printf("1 : %s", buff ); fgets(buff, 255, (FILE*)fp); printf("2: %s
", buff ); fgets(buff, 255, (FILE*)fp); printf("3: %s
", buff ); fclose(fp);}
输出
1 : This2: is testing for fprintf...3: This is testing for fputs...
以上就是在C语言中，FILE的数据类型是什么？的详细内容，更多请关注创想鸟其它相关文章！
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