dup2卡住了，但我不#39；我不知道为什么

因此，我试图在C中复制管道的功能，当使用dup2将管道用作输出时，程序将停止工作.它不会崩溃，只是有点冻结.我不认为我做错了什么...

这是子函数-

void    child(t_pipex pipex, char *cmd)
{
    int i;
    int err;
    char    *temp_path;

    i = 0;
    printf("Child: made it to my function\n");
    printf("Child: fd1 = %d\n", pipex.fd1);
    printf("Child: tube[1] = %d\n", pipex.tube[1]);
    err = dup2(pipex.tube[1], STDOUT_FILENO);
    printf("Child: dup2 (1): %d\n", err);
    close(pipex.tube[0]);
    printf("Child: First dup2 worked\n");
    dup2(pipex.fd1, 0);
    printf("Child: Second dup2 worked\n");

    pipex.split_cmd = ft_split(cmd, ' ');
    while (pipex.all_paths[i])
    {       
        temp_path = ft_join(pipex.all_paths[i], pipex.split_cmd[0]);
        if(access(temp_path, F_OK | X_OK) == 0)
        {
            printf("Child: access success\n");
            err = execve(temp_path, &pipex.split_cmd[1], pipex.environment);
            if (err == -1)
            {
                printf("Child: error...\n");
                free(temp_path);
                perror("child execve");
            }
        }
        i++;
    }
    printf("Child: closing pipe...\n");
    close(pipex.tube[1]);

}

调用my child函数的函数-

void    ft_pipex(t_pipex pipex, char **argv)
{
    int spoon;

    spoon = fork();
    if (spoon < 0)
        perror("Fork:");
    if (spoon == 0)
    {
        //CHILD
        pipex.pid1 = spoon; //I THINK
        child(pipex, argv[2]);
    }
    else
    {
        //PARENT
        pipex.pid2 = spoon; //I THINK
        parent(pipex, argv[3]);
    }
}

和我的主要功能-

int main(int argc, char **argv, char **envp)
{
    t_pipex pipex;

    if (argc != 5)
    {
        printf("Please use only 4 arguments\n");
        //printf("infile   command1    command2    outfile\n");
        return (0);
    }
    if (pipe(pipex.tube) < 0)
        perror("Pipe");
    pipex.path = (string_finder(envp, "PATH=") + 5);
    pipex.all_paths = ft_joinall(ft_split(pipex.path, ':'), "/");
    pipex.fd1 = open(argv[1], O_RDONLY);
    pipex.fd2 = open(argv[4], O_CREAT | O_RDWR | O_TRUNC, 0644);
    pipex.environment = envp;   
    ft_pipex(pipex, argv);
}

t_pipex如下:

typedef struct s_pipex
{
    int tube[2];
    int fd1;
    int fd2;
    int pid1;
    int pid2;
    char    *path;
    char    **all_paths;
    char    **split_cmd;
    char    **environment;
}   t_pipex;

输出...

Child: made it to my function
Child: fd1 = 5
Child: tube[1] = 4
A NULL argv[0] was passed through an exec system call.
^C

无论我是否注释掉dup2，都会出现空argv [0].我把什么地方搞砸了吗？

抱歉之前的错误，这是我的第一个帖子，我真的不知道我在做什么.谢谢