0

我想操纵Stdin然后Std*. 但我收到以下错误，

$ gcc testFd.c                                                                 
testFd.c:9: error: initializer element is not constant
testFd.c:9: warning: data definition has no type or storage class
testFd.c:10: error: redefinition of `fd'
testFd.c:9: error: `fd' previously defined here
testFd.c:10: error: `mode' undeclared here (not in a function)
testFd.c:10: error: initializer element is not constant
testFd.c:10: warning: data definition has no type or storage class
testFd.c:12: error: syntax error before string constant

该程序如下所示。 

#include <stdio.h>
#include <sys/ioctl.h>

int STDIN_FILENO = 1;
// I want to access typed 
// Shell commands, dunno about the value:
unsigned long F_DUPFD;

fd = fcntl(STDIN_FILENO, F_DUPFD, 0);
fd = open("/dev/fd/0", mode);

printf("STDIN = %s", fd);

更新的错误：只是试图让一个关于文件描述符的示例程序在 C 中工作，错误报告非常丢失

#include <stdio.h>
#include <sys/ioctl.h>

int main (void) {
    int STDIN_FILENO;
    // I want to access typed 
    // Shell commands, dunno about the value:
    unsigned long F_DUPFD;
    int fd;
    const char mode = 'r';

    fd = fcntl(STDIN_FILENO, F_DUPFD, 0);
    /* also, did you mean `fopen'? */
    fd = fopen("/dev/fd/0", mode);

    printf("STDIN = %s", fd);

    return 0;
}

程序执行如下图所示。

$ gcc testFd.c                                                                
testFd.c: In function `main':
testFd.c:14: warning: passing arg 2 of `fopen' makes pointer from integer without a cast
testFd.c:14: warning: assignment makes integer from pointer without a cast
4

4 回答 4

3

尝试使用一种main方法：

#include <stdio.h>
#include <sys/ioctl.h>

int main (void) {
    int STDIN_FILENO = 1;
    // I want to access typed 
    // Shell commands, dunno about the value:
    unsigned long F_DUPFD;
    /* also, declare the type of your variable "fd" */
    int fd;

    fd = fcntl(STDIN_FILENO, F_DUPFD, 0);
    /* also, did you mean `fopen'? */
    fd = open("/dev/fd/0", mode);

    printf("STDIN = %s", fd);

    return 0;
}
于 2010-06-05T23:28:38.847 回答
2

除了您没有main()功能这一事实之外，您的整个方法都是错误的。 STDIN_FILENO是一个常数；分配给它没有任何意义。

试着用一些细节解释你真正想做的事情，我们将能够建议如何去做。

于 2010-06-06T02:02:34.613 回答
2

你忘记了你的 main() 函数！！

于 2010-06-05T23:27:17.893 回答
2

你的定义在哪里main()？

于 2010-06-05T23:27:38.707 回答