c - 追加 "a+"是否自动将光标置于末尾

Question

我想用 c 打开一个文件，然后向其中添加一些内容并关闭它。我只是想知道 fopen 中的 a+ 自动导航到文件的最后一个字符。

Answer 1

是的。

为什么不尝试一下，或者阅读一下手册呢？

这里是:

   r      Open text file for reading.  The stream is positioned at the beginning of the file.

   r+     Open for reading and writing.  The stream is positioned at the beginning of the file.

   w      Truncate file to zero length or create text file for writing.  The stream is positioned at the  beginning  of  the
          file.

   w+     Open for reading and writing.  The file is created if it does not exist, otherwise it is truncated.  The stream is
          positioned at the beginning of the file.

   a      Open for appending (writing at end of file).  The file is created if it does not exist.  The stream is  positioned
          at the end of the file.

   a+     Open  for  reading and appending (writing at end of file).  The file is created if it does not exist.  The initial
          file position for reading is at the beginning of the file, but output is always appended to the end of the file.