将Execl命令的结果(是目录列表）输送到父进程

我正在对Linux中的过程管理进行一些练习，以及如何使用孩子和父母之间的系统呼叫和通信。我需要实现一个管道以获取子流程提供的字符串，该流程是字符串的目录列表，并将其传递到父进程以计数该字符串中的行数，并通过执行此操作来查找该目录中的文件数量。我遇到的问题在这里：

错误：初始化器无法确定" dirfilelist"的大小 char dirfilelist [] = read（隧道[0]，buf，max_buf）

我的代码也下面是：

#define die(e) do { fprintf(stderr, "%sn", e); exit(EXIT_FAILURE); }    while (0);
#define MAX_BUF 2024
int main()
{
const char *path = (char *)"/";                              /* Root path */
const char *childCommand = (char *)"ls |";                   /* Command to be executed by the child process */
const char *parentCommand = (char *)"wc -l";                 /* Command to be executed by the parent process */
int i = 0;                                                   /* A simple loop counter :) */
int counter = 0;                                             /* Counts the number of lines in the string provided in the child process */
int dirFileNum;                                              /* Keeps the list of files in the directory */
int tunnel[2];                                               /* Defining an array of integer to let the child process store a number and parent process to pick that number */
pid_t pID = fork(); 
char buf[MAX_BUF];                                           /* Fork from the main process */

if (pipe(tunnel) == -1)                                      /* Pipe from the parent to the child */
    die("pipe died.");
if(pID == -1)                                                /* Check if the fork result is valid */
{
    die("fork died.");
}   
else if(pID == 0)                                            /* Check if we are in the child process */ 
{
    dup2 (tunnel[1], STDOUT_FILENO);                         /* Redirect standard output */                 
    close(tunnel[0]);
    close(tunnel[1]);
    execl(childCommand, path);                               /* Execute the child command */
    die("execl died.");
}   
else                                                         /* When we are still in the main process */
{
    close(tunnel[1]);
    char dirFileList[] = read(tunnel[0],buf,MAX_BUF);                    /* Read the list of directories provided by the child process */
    for(i;i<strlen(dirFileList);i++)                         /* Find the number of lines in the list provided by the child process */
        if(dirFileList[i] == 'n')
            counter++;
    printf("Root contains %d files.", counter);              /* Print the result */
    wait(NULL);                                              /* Wait until the job is done by the child process */
}       
return 0;       
 }