feat: Use docker api to pull files from container

docker_agent_sandbox/tools/read_file.py

@@ -2,7 +2,6 @@
 
 from __future__ import annotations
 
-from shlex import quote
 from typing import TYPE_CHECKING
 
 from langchain_core.tools import BaseTool, tool
@@ -25,36 +24,29 @@ def make_read_file_tool(sandbox: "DockerSandbox") -> BaseTool:
 
         *offset* is the number of bytes to skip from the start of the file.
         *length* is the maximum number of bytes to return.  If the file is
-        longer than ``offset + length``, the
-        output is trimmed and a summary line is appended showing how many
-        bytes were omitted.
+        longer than ``offset + length``, the output is trimmed and a summary
+        line is appended showing how many bytes were omitted.
 
         Returns the (possibly trimmed) file contents as text, or an error message.
         """
         logger.debug(
             "Reading file inside sandbox: {} offset={} length={}", path, offset, length
         )
-        exit_code, wc_out = sandbox.exec(f"wc -c -- {quote(path)}")
-        if exit_code != 0:
-            return f"[ERROR reading {path!r}] {wc_out.strip()}"
         try:
-            total = int(wc_out.split()[0])
-        except (ValueError, IndexError):
-            return f"[ERROR parsing file size for {path!r}] {wc_out.strip()}"
+            data = sandbox.read_file(path)
+        except (FileNotFoundError, IsADirectoryError, RuntimeError) as exc:
+            return f"[ERROR reading {path!r}] {exc}"
 
-        exit_code, chunk = sandbox.exec(
-            f"dd if={quote(path)} iflag=skip_bytes,count_bytes"
-            f" skip={offset} count={length} 2>/dev/null"
-        )
-        if exit_code != 0:
-            return f"[ERROR reading {path!r}] {chunk.strip()}"
+        total = len(data)
+        chunk = data[offset : offset + length]
+        text = chunk.decode("utf-8", errors="replace")
 
         suffix = ""
         if offset + length < total:
             remaining = total - (offset + length)
             suffix = f"\n[... {remaining} more bytes not shown (total {total} bytes). Use offset/length to read further.]"
         elif offset > 0 or total > length:
-            suffix = f"\n[File total: {total} bytes, showing {len(chunk)} chars from offset {offset}.]"
-        return chunk + suffix
+            suffix = f"\n[File total: {total} bytes, showing {len(chunk)} bytes from offset {offset}.]"
+        return text + suffix
 
     return read_file