部分完成了readdir

user/libs/libc/dirent.c

@@ -0,0 +1,71 @@
+#include "dirent.h"
+#include "unistd.h"
+#include "stdio.h"
+#include "fcntl.h"
+#include "stddef.h"
+#include "stdlib.h"
+#include "string.h"
+#include <libsystem/syscall.h>
+
+/**
+ * @brief 打开文件夹
+ *
+ * @param dirname
+ * @return DIR*
+ */
+struct DIR *opendir(const char *path)
+{
+    int fd = open(path, O_DIRECTORY);
+    if (fd < 0) // 目录打开失败
+        return NULL;
+
+    // 分配DIR结构体
+    struct DIR *dirp = (struct DIR *)malloc(sizeof(struct DIR));
+    memset(dirp, 0, sizeof(struct DIR));
+    dirp->fd = fd;
+    dirp->buf_len = DIR_BUF_SIZE;
+    dirp->buf_pos = 0;
+
+    return dirp;
+}
+
+/**
+ * @brief 关闭文件夹
+ *
+ * @param dirp DIR结构体指针
+ * @return int 成功：0， 失败：-1
++--------+--------------------------------+
+| errno  |              描述               |
++--------+--------------------------------+
+|   0    |              成功               |
+| -EBADF | 当前dirp不指向一个打开了的目录      |
+| -EINTR |     函数执行期间被信号打断         |
++--------+--------------------------------+
+ */
+int closedir(struct DIR *dirp)
+{
+    int retval = close(dirp->fd);
+    free(dirp);
+    return retval;
+}
+
+int64_t getdents(int fd, struct dirent *dirent, long count)
+{
+    return syscall_invoke(SYS_GET_DENTS, fd, (uint64_t)dirent, count, 0, 0, 0, 0, 0);
+}
+/**
+ * @brief 从目录中读取数据
+ *
+ * @param dir
+ * @return struct dirent*
+ */
+struct dirent *reaaddir(struct DIR *dir)
+{
+    memset(dir, 0, DIR_BUF_SIZE);
+    int len = getdents(dir->fd, (struct dirent *)dir->buf, DIR_BUF_SIZE);
+
+    if (len > 0)
+        return (struct dirent *)dir->buf;
+    else
+        return NULL;
+}