一、linux下高级应用编程--stdio.h

最新推荐文章于 2025-05-17 17:05:17 发布

原创最新推荐文章于 2025-05-17 17:05:17 发布 · 925 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#linux #编程 #character #integer #filenames #stream

Prog.--C/C++ 专栏收录该内容

1 篇文章

订阅专栏

本文详细介绍了stdio.h头文件中的宏定义及其含义，并重点解释了fflush函数的作用及使用方法。了解这些内容有助于掌握C语言标准输入输出的基本操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

stdio.h 标准函数输入/输出

<stdio.h>头文件中用一些整数定义下列一些宏：

BUFSIZ：<stdio.h>中缓冲区的大小 _IOFBF：输入/输出全缓冲. _IOLBF：输入/输出行缓冲.当向缓冲区输入一个换行符时，缓冲区的内容会被flush。 _IONBF：输入/输出不缓冲. L_ctermid

^[CX]

Maximum size of character array to hold ctermid() output. [Option End]

L_tmpnam

Maximum size of character array to hold tmpnam() output.

SEEK_CUR

Seek relative to current position.

SEEK_END

Seek relative to end-of-file.

SEEK_SET

Seek relative to start-of-file.

The following macros shall be defined as positive integer constant expressions which denote implementation limits:

{FILENAME_MAX}

Maximum size in bytes of the longest filename string that the implementation guarantees can be opened.

{FOPEN_MAX}

Number of streams which the implementation guarantees can be open simultaneously. The value is at least eight.

{TMP_MAX}

Minimum number of unique filenames generated by tmpnam(). Maximum number of timesan application can call tmpnam() reliably. The value of {TMP_MAX} is at least 25. ^[XSI] [Option Start]

On XSI-conformant systems, the value of {TMP_MAX} is at least 10000. [Option End]

The following macro name shall be defined as a negative integer constant expression:

EOF

End-of-file return value.

The following macro name shall be defined as a null pointer constant:

NULL

Null pointer.

The following macro name shall be defined as a string constant:

P_tmpdir

^[XSI]

Default directory prefix for tempnam(). [Option End]

定义函数：int fflush(FILE *stream)

函数说明：fflush()会强迫将缓冲区内的数据写回参数stream指定的文件中。如果参数stream为NULL， fflush()会将所有打开的文件数据更新。
返回值：成功则返回0, 失败返回EOF, 错误代码存于errno中