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Merged
jgarzik merged 1 commit into from
Jul 12, 2025
Merged

chown implementation #411

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148 changes: 38 additions & 110 deletions tree/chgrp.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -9,37 +9,17 @@

mod common;

use self::common::error_string;
use self::common::{chown_traverse, error_string, ChangeOwnershipArgs};
use clap::Parser;
use gettextrs::{bind_textdomain_codeset, gettext, setlocale, textdomain, LocaleCategory};
use std::{cell::RefCell, ffi::CString, io, os::unix::fs::MetadataExt};
use std::{ffi::CString, io};

/// chgrp - change file group ownership
#[derive(Parser)]
#[command(version, about, disable_help_flag = true)]
struct Args {
#[arg(long, action = clap::ArgAction::HelpLong)] // Bec. help clashes with -h
help: Option<bool>,

/// Change symbolic links, rather than the files they point to
#[arg(short = 'h', long, default_value_t = false)]
no_derereference: bool,

/// Follow command line symlinks during -R recursion
#[arg(short = 'H', overrides_with_all = ["follow_cli", "follow_symlinks", "follow_none"])]
follow_cli: bool,

/// Follow symlinks during -R recursion
#[arg(short = 'L', overrides_with_all = ["follow_cli", "follow_symlinks", "follow_none"])]
follow_symlinks: bool,

/// Never follow symlinks during -R recursion
#[arg(short = 'P', overrides_with_all = ["follow_cli", "follow_symlinks", "follow_none"], default_value_t = true)]
follow_none: bool,

/// Recursively change groups of directories and their contents
#[arg(short, short_alias = 'R', long)]
recurse: bool,
#[command(flatten)]
delegate: ChangeOwnershipArgs,

/// A group name from the group database or a numeric group ID
group: String,
Expand All @@ -48,89 +28,6 @@ struct Args {
files: Vec<String>,
}

fn chgrp_file(filename: &str, gid: Option<u32>, args: &Args) -> bool {
let recurse = args.recurse;
let no_derereference = args.no_derereference;

let terminate = RefCell::new(false);

ftw::traverse_directory(
filename,
|entry| {
if *terminate.borrow() {
return Ok(false);
}

let md = entry.metadata().unwrap();

// According to the spec:
// "The user ID of the file shall be used as the owner argument."
let uid = md.uid();

// Don't change the group ID if the group argument is empty
let gid = gid.unwrap_or(libc::gid_t::MAX);

let ret = unsafe {
libc::fchownat(
entry.dir_fd(),
entry.file_name().as_ptr(),
uid,
gid,
// Default is to change the file that the symbolic link points to unless the
// -h flag is specified.
if no_derereference {
libc::AT_SYMLINK_NOFOLLOW
} else {
0
},
)
};
if ret != 0 {
let e = io::Error::last_os_error();
let err_str = match e.kind() {
io::ErrorKind::PermissionDenied => {
gettext!("cannot access '{}': {}", entry.path(), error_string(&e))
}
_ => {
gettext!("changing group of '{}': {}", entry.path(), error_string(&e))
}
};
eprintln!("chgrp: {}", err_str);
*terminate.borrow_mut() = true;
return Err(());
}

Ok(recurse)
},
|_| Ok(()), // Do nothing on `postprocess_dir`
|entry, error| {
let e = error.inner();
let err_str = match e.kind() {
io::ErrorKind::PermissionDenied => {
gettext!(
"cannot read directory '{}': {}",
entry.path(),
error_string(&e)
)
}
_ => {
gettext!("changing group of '{}': {}", entry.path(), error_string(&e))
}
};
eprintln!("chgrp: {}", err_str);
*terminate.borrow_mut() = true;
},
ftw::TraverseDirectoryOpts {
follow_symlinks_on_args: args.follow_cli,
follow_symlinks: args.follow_symlinks,
..Default::default()
},
);

let failed = *terminate.borrow();
!failed
}

// lookup string group by name, or parse numeric group ID
fn parse_group(group: &str) -> Result<Option<u32>, String> {
// empty strings are accepted without errors
Expand All @@ -155,13 +52,37 @@ fn parse_group(group: &str) -> Result<Option<u32>, String> {
}
}

fn err_handler(e: io::Error, path: ftw::DisplayablePath) {
let err_str = match e.kind() {
io::ErrorKind::PermissionDenied => {
gettext!("cannot read directory '{}': {}", path, error_string(&e))
}
_ => {
gettext!("changing group of '{}': {}", path, error_string(&e))
}
};
eprintln!("chgrp: {}", err_str);
}

fn chown_err_handler(e: io::Error, path: ftw::DisplayablePath) {
let err_str = match e.kind() {
io::ErrorKind::PermissionDenied => {
gettext!("cannot access '{}': {}", path, error_string(&e))
}
_ => {
gettext!("changing group of '{}': {}", path, error_string(&e))
}
};
eprintln!("chgrp: {}", err_str);
}

fn main() -> Result<(), Box<dyn std::error::Error>> {
// parse command line arguments
let mut args = Args::parse();

// Enable `no_derereference` if `-R` is enabled without either `-H` or `-L`
if args.recurse && !(args.follow_cli || args.follow_symlinks) {
args.no_derereference = true;
if args.delegate.recurse && !(args.delegate.follow_cli || args.delegate.follow_symlinks) {
args.delegate.no_dereference = true;
}

// initialize translations
Expand All @@ -182,7 +103,14 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {

// apply the group to each file
for filename in &args.files {
let success = chgrp_file(filename, gid, &args);
let success = chown_traverse(
filename,
None,
gid,
&args.delegate,
err_handler,
chown_err_handler,
);
if !success {
exit_code = 1;
}
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