fileno()函数链接出错，急！

xiaochengwx

我在用dup2(fileno(fp1),fileno(fp2))时，链接时gcc说_fileno()是未定义的引用。头文件我已加入<stdlib.h>了。请问是不是和其它库冲突？fileno()又是在哪个库中呢？
源代码是C语言。

_z_

man fileno

chaisave

please make sure that you are using `gcc' to compile this source instead of `g++'
if you are writing a C++ program, please
[code:1]
#include <cstdlib>
#include <cstdio>
#include <unistd.h>
[/code:1]
and keep using g++

suke

Please refer to http://www.opengroup.org/onlinepubs/007908799/, which is standard POSIX specification for Unix, but also can be used for Linux