Example code to skip hidden files breaks WalkDir::new(".")

[kpcyrd]

This is currently recommended to skip hidden directories in the docs:

use walkdir::{DirEntry, WalkDir};

fn is_hidden(entry: &DirEntry) -> bool {
    entry.file_name()
         .to_str()
         .map(|s| s.starts_with("."))
         .unwrap_or(false)
}

for entry in WalkDir::new("foo")
                     .into_iter()
                     .filter_entry(|e| !is_hidden(e)) {
    println!("{}", entry?.path().display());
}

This works well for foo, but breaks if . is provided instead (playground):

use walkdir::{WalkDir, DirEntry}; // 2.3.2

fn matches(entry: &DirEntry) -> bool {
    let hidden = entry.file_name()
         .to_str()
         .map(|s| s.starts_with("."))
         .unwrap_or(false);

    if hidden {
        println!("Skipping because hidden: {:?}", entry);
    }

    !hidden
}

fn walk(path: &str) {
    println!("Walking: {:?}", path);
    let walker = WalkDir::new(path).into_iter();
    for entry in walker.filter_entry(matches) {
        println!("{:?}", entry);
    }
}

fn main() {
    walk(".");
    walk("/etc");
}

Output:

Walking: "."
Skipping because hidden: DirEntry(".")
Walking: "/etc"
Ok(DirEntry("/etc"))
Ok(DirEntry("/etc/issue.net"))
Ok(DirEntry("/etc/bindresvport.blacklist"))
Ok(DirEntry("/etc/rc1.d"))
Ok(DirEntry("/etc/hostname"))
Ok(DirEntry("/etc/xattr.conf"))
Ok(DirEntry("/etc/resolv.conf"))
Ok(DirEntry("/etc/pam.conf"))
Ok(DirEntry("/etc/mke2fs.conf"))
Ok(DirEntry("/etc/e2scrub.conf"))
Ok(DirEntry("/etc/update-motd.d"))
Ok(DirEntry("/etc/update-motd.d/50-motd-news"))
Ok(DirEntry("/etc/update-motd.d/10-help-text"))
Ok(DirEntry("/etc/update-motd.d/00-header"))
Ok(DirEntry("/etc/update-motd.d/60-unminimize"))
Ok(DirEntry("/etc/terminfo"))
Ok(DirEntry("/etc/terminfo/README"))
Ok(DirEntry("/etc/alternatives"))
Ok(DirEntry("/etc/alternatives/w"))
Ok(DirEntry("/etc/alternatives/README"))
Ok(DirEntry("/etc/alternatives/pager"))
Ok(DirEntry("/etc/alternatives/awk"))
Ok(DirEntry("/etc/alternatives/nawk"))
Ok(DirEntry("/etc/alternatives/rmt"))
Ok(DirEntry("/etc/alternatives/lzma"))
Ok(DirEntry("/etc/alternatives/rsh"))
Ok(DirEntry("/etc/alternatives/cpp"))
Ok(DirEntry("/etc/alternatives/fakeroot"))
Ok(DirEntry("/etc/alternatives/lzfgrep"))
Ok(DirEntry("/etc/alternatives/cc"))
Ok(DirEntry("/etc/alternatives/lzcat"))
Ok(DirEntry("/etc/alternatives/c++"))
Ok(DirEntry("/etc/alternatives/lzegrep"))
Ok(DirEntry("/etc/alternatives/c99"))
Ok(DirEntry("/etc/alternatives/lzgrep"))
Ok(DirEntry("/etc/alternatives/unlzma"))
Ok(DirEntry("/etc/alternatives/lzmore"))
Ok(DirEntry("/etc/alternatives/lzless"))
Ok(DirEntry("/etc/alternatives/lzdiff"))
Ok(DirEntry("/etc/alternatives/rcp"))
Ok(DirEntry("/etc/alternatives/c89"))
Ok(DirEntry("/etc/alternatives/rlogin"))
Ok(DirEntry("/etc/alternatives/lzcmp"))
Ok(DirEntry("/etc/alternatives/pinentry"))
Ok(DirEntry("/etc/ld.so.cache"))
Ok(DirEntry("/etc/networks"))
Ok(DirEntry("/etc/profile"))
Ok(DirEntry("/etc/debconf.conf"))
Ok(DirEntry("/etc/security"))
Ok(DirEntry("/etc/security/limits.conf"))
Ok(DirEntry("/etc/security/access.conf"))
Ok(DirEntry("/etc/security/sepermit.conf"))
Ok(DirEntry("/etc/security/faillock.conf"))
Ok(DirEntry("/etc/security/opasswd"))
Ok(DirEntry("/etc/security/namespace.init"))
Ok(DirEntry("/etc/security/namespace.d"))
Ok(DirEntry("/etc/security/limits.d"))
Ok(DirEntry("/etc/security/pam_env.conf"))
Ok(DirEntry("/etc/security/group.conf"))
Ok(DirEntry("/etc/security/time.conf"))
Ok(DirEntry("/etc/security/namespace.conf"))
Skipping because hidden: DirEntry("/etc/.pwd.lock")
Ok(DirEntry("/etc/gai.conf"))
Ok(DirEntry("/etc/dpkg"))
Ok(DirEntry("/etc/dpkg/dpkg.cfg"))
Ok(DirEntry("/etc/dpkg/origins"))
Ok(DirEntry("/etc/dpkg/origins/ubuntu"))
Ok(DirEntry("/etc/dpkg/origins/default"))
Ok(DirEntry("/etc/dpkg/origins/debian"))
Ok(DirEntry("/etc/dpkg/dpkg.cfg.d"))
Ok(DirEntry("/etc/dpkg/dpkg.cfg.d/excludes"))
Ok(DirEntry("/etc/dpkg/dpkg.cfg.d/docker-apt-speedup"))
Ok(DirEntry("/etc/dpkg/dpkg.cfg.d/pkg-config-hook-config"))
Ok(DirEntry("/etc/dpkg/shlibs.override"))
Ok(DirEntry("/etc/dpkg/shlibs.default"))
Ok(DirEntry("/etc/rc3.d"))
Ok(DirEntry("/etc/fstab"))
Ok(DirEntry("/etc/gshadow"))
Ok(DirEntry("/etc/sysctl.conf"))
Ok(DirEntry("/etc/rc2.d"))
Ok(DirEntry("/etc/selinux"))
Ok(DirEntry("/etc/selinux/semanage.conf"))
Ok(DirEntry("/etc/ld.so.conf.d"))
Ok(DirEntry("/etc/ld.so.conf.d/libc.conf"))
Ok(DirEntry("/etc/ld.so.conf.d/x86_64-linux-gnu.conf"))
Ok(DirEntry("/etc/ld.so.conf.d/fakeroot-x86_64-linux-gnu.conf"))
Ok(DirEntry("/etc/os-release"))
Ok(DirEntry("/etc/libaudit.conf"))
Ok(DirEntry("/etc/login.defs"))
Ok(DirEntry("/etc/skel"))
Skipping because hidden: DirEntry("/etc/skel/.bash_logout")
Skipping because hidden: DirEntry("/etc/skel/.profile")
Skipping because hidden: DirEntry("/etc/skel/.bashrc")
Ok(DirEntry("/etc/shells"))
Ok(DirEntry("/etc/rc4.d"))
Ok(DirEntry("/etc/cron.d"))
[...]

I'm wondering if walkdir::FilterEntry could be extended with a method to make the initial path skip the filter. Alternatively is_hidden could be enhanced to check for . and .. since filter_entry should never try these unless the path was the initial folder.

The example code in the docs should be updated to include this change.

Thanks!

[gifnksm]

For reference, using entry.path().file_name() instead of entry.file_name() seems to work.

fn is_hidden(entry: &walkdir::DirEntry) -> bool {
    entry
        .path()
        .file_name()
        .and_then(|file_name| file_name.to_str().map(|s| s.starts_with('.')))
        .unwrap_or(false)
}

---

Path::new(".").file_name() and Path::new("..").file_name() return None.

https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=264e8981f52264894f80691bbb0969d4

In this case, walkdir::DirEntry::file_name returns the entire path, which is incorrectly determined to be a hidden file.

walkdir/src/dent.rs

Lines 166 to 168 in abf3a15

	pub fn file_name(&self) -> &OsStr {
	self.path.file_name().unwrap_or_else(|| self.path.as_os_str())
	}