重新标记stdout和stdin(Redericting stdout and stdin)

 我想重新发送stdout，stderr来文件和来自char *的stdin。 我的目标是用C语言。 
 
 当我运行此代码时： 
 
int main(){
        stdout=fopen("/home/user/file.txt","w");
    printf("aaaa");
    printf("\nbbbb");
    system("/bin/bash");
    sprintf("stdin","exit");
    return 0;
}
 
 文件没有一些字符串和bash从控制台获取参数。 虫子在哪里？ 

I would like to redericting stdout, stderr to file and stdin from char*. My goal is make it in C.
 
When i run this code:
 
int main(){
        stdout=fopen("/home/user/file.txt","w");
    printf("aaaa");
    printf("\nbbbb");
    system("/bin/bash");
    sprintf("stdin","exit");
    return 0;
}
 
File didn't have for some string and bash take argument from console. Where is bug??

原文：https://stackoverflow.com/questions/8218717