chgrp: Add chgrp.py

Author: Expertcoderz

userland/utilities/chgrp.py

@@ -0,0 +1,267 @@
+import grp
+import pwd
+import shutil
+import sys
+from pathlib import Path
+
+from tqdm import tqdm
+
+from .. import core
+
+
+parser = core.create_parser(
+    usage=(
+        "%prog [OPTION]... GROUP FILE...",
+        "%prog [OPTION]... --reference=RFILE FILE...",
+    ),
+    description="Change the group ownership of each FILE.",
+)
+
+parser.add_option(
+    "-f",
+    "--silent",
+    "--quiet",
+    dest="verbosity",
+    action="store_const",
+    const=0,
+    default=1,
+    help="suppress most error messages",
+)
+parser.add_option(
+    "-c",
+    "--changes",
+    dest="verbosity",
+    action="store_const",
+    const=2,
+    help="report only when changes are made",
+)
+parser.add_option(
+    "-v",
+    "--verbose",
+    dest="verbosity",
+    action="store_const",
+    const=3,
+    help="print a diagnostic for each file",
+)
+
+parser.add_option(
+    "--progress",
+    dest="progress",
+    action="store_true",
+    help="show a progress bar when changing groups",
+)
+parser.add_option(
+    "--no-progress",
+    dest="progress",
+    action="store_false",
+    default=False,
+    help="do not show a progress bar (default)",
+)
+
+parser.add_option(
+    "--dereference",
+    action="store_true",
+    default=True,
+    help="affect symlink referents instead of the symlinks themselves (default)",
+)
+parser.add_option(
+    "-h",
+    "--no-dereference",
+    dest="dereference",
+    action="store_false",
+    help="opposite of --dereference",
+)
+
+parser.add_option(
+    "--no-preserve-root",
+    dest="preserve_root",
+    action="store_false",
+    default=False,
+    help="do not treat '/' specially (default)",
+)
+parser.add_option(
+    "--preserve-root",
+    action="store_true",
+    help="fail to operate recursively on '/'",
+)
+
+parser.add_option(
+    "--from",
+    dest="from_spec",  # prevent name collision with the `from` keyword
+    metavar="[CURRENT_OWNER][:CURRENT_GROUP]",
+    help="only affect files with CURRENT_OWNER and CURRENT_GROUP"
+    " (either is optional and only checked if given)",
+)
+
+parser.add_option(
+    "--reference",
+    metavar="RFILE",
+    help="use the group of RFILE instead of from an argument",
+)
+
+parser.add_option(
+    "-R", "--recursive", action="store_true", help="operate on directories recursively"
+)
+parser.add_option(
+    "-H",
+    dest="recurse_mode",
+    action="store_const",
+    const="H",
+    help="traverse directory symlinks only if they were given as command line arguments",
+)
+parser.add_option(
+    "-L",
+    dest="recurse_mode",
+    action="store_const",
+    const="L",
+    help="traverse all directory symlinks encountered",
+)
+parser.add_option(
+    "-P",
+    dest="recurse_mode",
+    action="store_const",
+    const="P",
+    default="P",
+    help="do not traverse any symlinks (default)",
+)
+
+
+@core.command(parser)
+def python_userland_chgrp(opts, args):
+    if not args:
+        parser.error("missing operand")
+
+    from_uid: int | None = None
+    from_gid: int | None = None
+
+    if opts.from_spec:
+        from_spec = opts.from_spec.split(":")
+
+        if from_spec[0]:
+            try:
+                from_uid = pwd.getpwnam(from_spec[0])
+            except KeyError:
+                parser.error(f"invalid user: '{opts.from_spec}'")
+
+        if len(from_spec) > 1 and from_spec[1]:
+            try:
+                from_gid = grp.getgrnam(from_spec[1])
+            except KeyError:
+                parser.error(f"invalid group: '{opts.from_spec}'")
+
+    gid: int
+    gname: str | None = None
+
+    if opts.reference:
+        try:
+            gid = Path(opts.reference).stat(follow_symlinks=True).st_gid
+        except OSError as e:
+            print(e, file=sys.stderr)
+            return 1
+    else:
+        gname = args.pop(0)
+
+        if not args:
+            parser.error(f"missing operand after '{gname}'")
+
+        if gname.isdecimal():
+            gid = int(gname)
+        else:
+            try:
+                gid = grp.getgrnam(gname).gr_gid
+            except KeyError:
+                parser.error(f"invalid group: '{gname}'")
+
+    failed = False
+
+    def chown(file: Path) -> None:
+        nonlocal failed
+
+        try:
+            stat = file.stat(follow_symlinks=opts.dereference)
+            prev_uid = stat.st_uid
+            prev_gid = stat.st_gid
+        except OSError as e:
+            failed = True
+            if opts.verbosity:
+                print(e, file=sys.stderr)
+                print(
+                    f"failed to change group of '{file}' to {gname or gid}",
+                    file=sys.stderr,
+                )
+            return
+
+        try:
+            prev_gname = grp.getgrgid(prev_gid).gr_name
+        except KeyError:
+            prev_gname = str(prev_gid)
+
+        # Note: while it's possible, we do not check if prev_gid == gid at
+        # this point because even if they are the same, an error should be
+        # printed if the current user has insufficient permission to change
+        # the group membership of that file (for coreutils compat).
+        if (from_uid is not None and prev_uid == from_uid) or (
+            from_gid is not None and prev_gid == from_gid
+        ):
+            if opts.verbosity > 2:
+                print(f"group of '{file}' retained as {prev_gname}")
+            return
+
+        try:
+            shutil.chown(file, group=gid, follow_symlinks=opts.dereference)
+        except OSError as e:
+            failed = True
+            if opts.verbosity:
+                print(e, file=sys.stderr)
+                if opts.verbosity:
+                    print(
+                        f"failed to change group of '{file}' to {gname or gid}",
+                        file=sys.stderr,
+                    )
+            return
+
+        if prev_gid == gid:
+            if opts.verbosity > 2:
+                print(f"group of '{file}' retained as {prev_gname}")
+        elif opts.verbosity > 1:
+            print(f"changed group of '{file}' from {prev_gname} to {gname or gid}")
+
+    files = map(
+        Path,
+        (
+            tqdm(args, ascii=True, desc="Changing group ownership")
+            if opts.progress
+            else args
+        ),
+    )
+
+    if opts.recursive:
+
+        def traverse(file: Path) -> None:
+            nonlocal failed
+
+            if opts.preserve_root and file.root == str(file):
+                print(
+                    f"recursive operation on '{file}' prevented; use --no-preserve-root to override",
+                    file=sys.stderr,
+                )
+                failed = True
+                return
+
+            for child in file.iterdir():
+                if child.is_dir(follow_symlinks=opts.recurse_mode == "L"):
+                    traverse(child)
+                chown(file)
+
+        for file in files:
+            if file.is_dir(
+                follow_symlinks=opts.recurse_mode == "H" or opts.recurse_mode == "L"
+            ):
+                traverse(file)
+            else:
+                chown(file)
+    else:
+        for file in files:
+            chown(file)
+
+    return int(failed)