lib.util.copy(): Add function

Add copy(src_uri, dst_uri), instatiating two ExecContext instances,
and doing the obvious with them - copying from src_uri to dst_uri.

Signed-off-by: Jan Lindemann <jan@janware.com>

src/python/jw/pkg/lib/util.py

@@ -6,7 +6,7 @@ from typing import TYPE_CHECKING, Iterable
 
 if TYPE_CHECKING:
     from typing import Sequence
-    from ExecContext import ExecContext
+    from .ExecContext import ExecContext
 
 import os, sys, json
 
@@ -99,6 +99,32 @@ async def run_sudo(cmd: list[str], *args, interactive: bool=True, ec: ExecContex
         ec = Local(interactive=interactive)
     return await ec.sudo(cmd, *args, **kwargs)
 
+async def copy(src_uri: str, dst_uri: str, owner: str|None=None, group: str|None=None, mode: str|None=None, throw=True) -> Exception|str:
+    from .ExecContext import ExecContext
+    src: ExecContext|None = None
+    dst: ExecContext|None = None
+    def __ec(uri: str) -> tuple[ExecContext, str]:
+        return ExecContext.create(uri), urlparse(uri).path
+    try:
+        src, src_path = __ec(src_uri)
+        content = (await src.get(src_path, throw=True)).stdout
+        dst, dst_path = __ec(dst_uri)
+        if os.path.isdir(dst_path) and not dst_path[-1] == '/':
+            dst_path += '/'
+        if dst_path[-1] == '/':
+            dst_path += os.path.basename(src_path)
+        await dst.put(path=dst_path, content=content, owner=owner, group=group, mode=mode, throw=True)
+    except Exception as e:
+        if throw:
+            raise
+        log(ERR, f'Failed to copy {src_uri} -> {dst_uri} ({str(e)})')
+        return e
+    finally:
+        for ec in [src, dst]:
+            if ec is not None:
+                await ec.close()
+    return dst_path
+
 async def get_username(args: Namespace|None=None, url: str|None=None, askpass_env: list[str]=[], ec: ExecContext|None=None) -> str: # export
     url_user = None if url is None else urlparse(url).username
     if args is not None: