From 4c92d8313594c2a797892024a282533ab4f16b49 Mon Sep 17 00:00:00 2001
From: yotamolenik <39271599+yotamolenik@users.noreply.github.com>
Date: Sat, 5 Feb 2022 16:39:56 +0200
Subject: [PATCH] linux_fs: add listdir

---
 src/pyzshell/pyzshell/linux_fs.py      | 27 +++++++++++++++++++++++---
 src/pyzshell/pyzshell/structs/linux.py | 13 ++++++++++++-
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/src/pyzshell/pyzshell/linux_fs.py b/src/pyzshell/pyzshell/linux_fs.py
index 80710f38..8bd9aa9c 100644
--- a/src/pyzshell/pyzshell/linux_fs.py
+++ b/src/pyzshell/pyzshell/linux_fs.py
@@ -1,9 +1,30 @@
+from struct import Struct
+from typing import List
+
 from pyzshell.fs import Fs
 
+from pyzshell.exceptions import ZShellError
+from pyzshell.structs.linux import dirent
+
 
 class LinuxFs(Fs):
     CHUNK_SIZE = 1024
 
-    def listdir(self, dirname: str) -> list:
-        """ get directory listing for a given dirname """
-        raise NotImplementedError()
+    def listdir(self, dirname='.') -> List[Struct]:
+        """ list directory contents(at remote).
+            calls readdir in a loop """
+        errno = self._client.symbols.errno
+        errno[0] = 0
+        dir_list = []
+        folder = self._client.symbols.opendir(dirname)
+        if folder == 0:
+            raise ZShellError('cannot open folder to listdir')
+        diren = self._client.symbols.readdir(folder)
+        while diren != 0:
+            entry = dirent.parse_stream(diren)
+            dir_list.append(entry)
+            diren = self._client.symbols.readdir(folder)
+        if errno[0] != 0:
+            raise ZShellError(f'readdir for listdir failed. ({self._client.errno})')
+        self._client.symbols.closedir(folder)
+        return dir_list
diff --git a/src/pyzshell/pyzshell/structs/linux.py b/src/pyzshell/pyzshell/structs/linux.py
index e93fd0fa..fbaae878 100644
--- a/src/pyzshell/pyzshell/structs/linux.py
+++ b/src/pyzshell/pyzshell/structs/linux.py
@@ -1,6 +1,7 @@
-from construct import Struct, PaddedString
+from construct import Struct, PaddedString, Int32ul, Int64ul, Int16ul, Int8ul, Bytes, Padding, Computed
 
 _UTSNAME_LENGTH = 65
+_D_NAME_LENGTH = 256
 
 utsname = Struct(
     'sysname' / PaddedString(_UTSNAME_LENGTH, 'utf8'),
@@ -9,3 +10,13 @@
     'version' / PaddedString(_UTSNAME_LENGTH, 'utf8'),
     'machine' / PaddedString(_UTSNAME_LENGTH, 'utf8'),
 )
+
+dirent = Struct(
+    'd_ino' / Int32ul,
+    Padding(4),
+    'd_off' / Int64ul,
+    'd_reclen' / Int16ul,
+    'd_type' / Int8ul,
+    '_d_name_bytes' / Bytes(_D_NAME_LENGTH),
+    'd_name' / Computed(lambda x: x._d_name_bytes.split(b'\x00', 1)[0].decode())
+)