Linux使用 man 查询C库中的fopen函数使用方法v

在Linux系统中，你可以使用`man`命令查看C库中的函数帮助文档，包括`fopen`函数。打开终端，输入以下指令：

man fopen

然后按回车键。这将会显示`man`手册页，详细介绍`fopen`函数的使用方法、参数、返回值以及可能出现的错误等信息。通常，帮助内容会按照这样的结构呈现：

NAME
       fopen - open a file

SYNOPSIS
       FILE *fopen(const char *filename, const char *mode);

DESCRIPTION
       The fopen() function opens the file named by filename for reading or writing.
       The mode string can include the following letters in any order:

       r     Open text file for reading (default).
       w     Truncate to zero length or create text file for writing.
       a     Append to end of text file; if nonexistent, create it.
       b     Open binary file for reading or writing.
       +     Update both read and write pointers at EOF.
       t     Text mode (clears 'b' bit).

       If you specify a file that does not exist yet, fopen() will create it only when you use 'w', 'a', or '+' modes.

RETURN VALUES
       On success, fopen() returns a pointer to the FILE structure associated with the opened stream. If an error occurs, NULL is returned and errno is set appropriately.

SEE ALSO
       fclose(), feof(), ferror(), fflush(), freopen()

ERRORS
       ... (列出可能出现的错误)