Struct cap_primitives::fs::Permissions

source ·

pub struct Permissions { /* private fields */ }

Expand description

Representation of the various permissions on a file.

This corresponds to std::fs::Permissions.

We need to define our own version because the libstd `Permissions` doesn't have a public constructor that we can use.

Implementations§

source §

impl Permissions

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pub fn from_std(std: Permissions) -> Self

Constructs a new instance of Self from the given std::fs::Permissions.

Examples found in repository ?

src/fs/metadata.rs (line 54)

    fn from_parts(std: fs::Metadata, ext: MetadataExt, file_type: FileType) -> Self {
        Self {
            file_type,
            len: std.len(),
            permissions: Permissions::from_std(std.permissions()),
            modified: std.modified().ok().map(SystemTime::from_std),
            accessed: std.accessed().ok().map(SystemTime::from_std),
            created: std.created().ok().map(SystemTime::from_std),
            ext,
        }
    }

source

pub fn into_std(self, file: &File) -> Result<Permissions>

Consumes self and produces a new instance of std::fs::Permissions.

The `file` parameter works around the fact that we can't construct a `Permissions` object ourselves on Windows.

Examples found in repository ?

src/rustix/linux/fs/set_permissions_impl.rs (line 13)

pub(crate) fn set_permissions_impl(
    start: &fs::File,
    path: &Path,
    perm: Permissions,
) -> io::Result<()> {
    let std_perm = perm.into_std(start)?;

    // First try using `O_PATH` and doing a chmod on `/proc/self/fd/{}`
    // (`fchmod` doesn't work on `O_PATH` file descriptors).
    //
    // This may fail, due to older Linux versions not supporting `O_PATH`, or
    // due to procfs being unavailable, but if it does work, go with it, as
    // `O_PATH` tells Linux that we don't actually need to read or write the
    // file, which may avoid side effects associated with opening device files.
    let result = set_permissions_through_proc_self_fd(start, path, std_perm.clone());
    if let Ok(()) = result {
        return Ok(());
    }

    // Then try `fchmod` with a normal handle. Normal handles need some kind of
    // access, so first try read.
    match open(start, path, OpenOptions::new().read(true)) {
        Ok(file) => return set_file_permissions(&file, std_perm),
        Err(err) => match rustix::io::Errno::from_io_error(&err) {
            Some(rustix::io::Errno::ACCESS) => (),
            _ => return Err(err),
        },
    }

    // Next try write.
    match open(start, path, OpenOptions::new().write(true)) {
        Ok(file) => return set_file_permissions(&file, std_perm),
        Err(err) => match rustix::io::Errno::from_io_error(&err) {
            Some(rustix::io::Errno::ACCESS) | Some(rustix::io::Errno::ISDIR) => (),
            _ => return Err(err),
        },
    }

    // Nothing worked, so just return the original error.
    result
}