Struct std::fs::Metadata
pub struct Metadata(_);
Metadata information about a file.
This structure is returned from the metadata or symlink_metadata function or method and represents known metadata about a file such as its permissions, size, modification times, etc.
Implementations
impl Metadata
pub fn file_type(&self) -> FileType
Returns the file type for this metadata.
Examples
fn main() -> std::io::Result<()> {
use std::fs;
let metadata = fs::metadata("foo.txt")?;
println!("{:?}", metadata.file_type());
Ok(())
}pub fn is_dir(&self) -> bool
Returns true if this metadata is for a directory. The result is mutually exclusive to the result of Metadata::is_file, and will be false for symlink metadata obtained from symlink_metadata.
Examples
fn main() -> std::io::Result<()> {
use std::fs;
let metadata = fs::metadata("foo.txt")?;
assert!(!metadata.is_dir());
Ok(())
}pub fn is_file(&self) -> bool
Returns true if this metadata is for a regular file. The result is mutually exclusive to the result of Metadata::is_dir, and will be false for symlink metadata obtained from symlink_metadata.
When the goal is simply to read from (or write to) the source, the most reliable way to test the source can be read (or written to) is to open it. Only using is_file can break workflows like diff <( prog_a ) on a Unix-like system for example. See File::open or OpenOptions::open for more information.
Examples
use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
assert!(metadata.is_file());
Ok(())
}pub fn is_symlink(&self) -> bool
Returns true if this metadata is for a symbolic link.
Examples
#![feature(is_symlink)]
use std::fs;
use std::path::Path;
use std::os::unix::fs::symlink;
fn main() -> std::io::Result<()> {
let link_path = Path::new("link");
symlink("/origin_does_not_exists/", link_path)?;
let metadata = fs::symlink_metadata(link_path)?;
assert!(metadata.is_symlink());
Ok(())
}pub fn len(&self) -> u64
Returns the size of the file, in bytes, this metadata is for.
Examples
use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
assert_eq!(0, metadata.len());
Ok(())
}pub fn permissions(&self) -> Permissions
Returns the permissions of the file this metadata is for.
Examples
use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
assert!(!metadata.permissions().readonly());
Ok(())
}pub fn modified(&self) -> Result<SystemTime>
Returns the last modification time listed in this metadata.
The returned value corresponds to the mtime field of stat on Unix platforms and the ftLastWriteTime field on Windows platforms.
Errors
This field might not be available on all platforms, and will return an Err on platforms where it is not available.
Examples
use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
if let Ok(time) = metadata.modified() {
println!("{:?}", time);
} else {
println!("Not supported on this platform");
}
Ok(())
}pub fn accessed(&self) -> Result<SystemTime>
Returns the last access time of this metadata.
The returned value corresponds to the atime field of stat on Unix platforms and the ftLastAccessTime field on Windows platforms.
Note that not all platforms will keep this field update in a file’s metadata, for example Windows has an option to disable updating this time when files are accessed and Linux similarly has noatime.
Errors
This field might not be available on all platforms, and will return an Err on platforms where it is not available.
Examples
use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
if let Ok(time) = metadata.accessed() {
println!("{:?}", time);
} else {
println!("Not supported on this platform");
}
Ok(())
}pub fn created(&self) -> Result<SystemTime>
Returns the creation time listed in this metadata.
The returned value corresponds to the btime field of statx on Linux kernel starting from to 4.11, the birthtime field of stat on other Unix platforms, and the ftCreationTime field on Windows platforms.
Errors
This field might not be available on all platforms, and will return an Err on platforms or filesystems where it is not available.
Examples
use std::fs;
fn main() -> std::io::Result<()> {
let metadata = fs::metadata("foo.txt")?;
if let Ok(time) = metadata.created() {
println!("{:?}", time);
} else {
println!("Not supported on this platform or filesystem");
}
Ok(())
}Trait Implementations
impl Clone for Metadata
fn clone(&self) -> Metadata
Returns a copy of the value. Read more
fn clone_from(&mut self, source: &Self)
Performs copy-assignment from source. Read more
impl Debug for Metadata
fn fmt(&self, f: &mut Formatter<'_>) -> Result
Formats the value using the given formatter. Read more
fn dev(&self) -> u64
Returns the ID of the device containing the file. Read more
fn ino(&self) -> u64
Returns the inode number. Read more
fn mode(&self) -> u32
Returns the rights applied to this file. Read more
fn nlink(&self) -> u64
Returns the number of hard links pointing to this file. Read more
fn uid(&self) -> u32
Returns the user ID of the owner of this file. Read more
fn gid(&self) -> u32
Returns the group ID of the owner of this file. Read more
fn rdev(&self) -> u64
Returns the device ID of this file (if it is a special one). Read more
fn size(&self) -> u64
Returns the total size of this file in bytes. Read more
fn atime(&self) -> i64
Returns the last access time of the file, in seconds since Unix Epoch. Read more
fn atime_nsec(&self) -> i64
fn mtime(&self) -> i64
Returns the last modification time of the file, in seconds since Unix Epoch. Read more
fn mtime_nsec(&self) -> i64
fn ctime(&self) -> i64
Returns the last status change time of the file, in seconds since Unix Epoch. Read more
fn ctime_nsec(&self) -> i64
fn blksize(&self) -> u64
Returns the block size for filesystem I/O. Read more
fn blocks(&self) -> u64
Returns the number of blocks allocated to the file, in 512-byte units. Read more
fn as_raw_stat(&self) -> &stat
other methods of this trait are now preferred
Gain a reference to the underlying stat structure which contains the raw information returned by the OS. Read more
fn st_dev(&self) -> u64
Returns the device ID on which this file resides. Read more
fn st_ino(&self) -> u64
Returns the inode number. Read more
fn st_mode(&self) -> u32
Returns the file type and mode. Read more
fn st_nlink(&self) -> u64
Returns the number of hard links to file. Read more
fn st_uid(&self) -> u32
Returns the user ID of the file owner. Read more
fn st_gid(&self) -> u32
Returns the group ID of the file owner. Read more
fn st_rdev(&self) -> u64
Returns the device ID that this file represents. Only relevant for special file. Read more
fn st_size(&self) -> u64
Returns the size of the file (if it is a regular file or a symbolic link) in bytes. Read more
fn st_atime(&self) -> i64
Returns the last access time of the file, in seconds since Unix Epoch. Read more
fn st_atime_nsec(&self) -> i64
fn st_mtime(&self) -> i64
Returns the last modification time of the file, in seconds since Unix Epoch. Read more
fn st_mtime_nsec(&self) -> i64
fn st_ctime(&self) -> i64
Returns the last status change time of the file, in seconds since Unix Epoch. Read more
fn st_ctime_nsec(&self) -> i64
fn st_blksize(&self) -> u64
Returns the “preferred” block size for efficient filesystem I/O. Read more
fn st_blocks(&self) -> u64
Returns the number of blocks allocated to the file, 512-byte units. Read more
fn dev(&self) -> u64
Returns the st_dev field of the internal filestat_t
fn ino(&self) -> u64
Returns the st_ino field of the internal filestat_t
fn nlink(&self) -> u64
Returns the st_nlink field of the internal filestat_t
fn size(&self) -> u64
Returns the st_size field of the internal filestat_t
fn atim(&self) -> u64
Returns the st_atim field of the internal filestat_t
fn mtim(&self) -> u64
Returns the st_mtim field of the internal filestat_t
fn ctim(&self) -> u64
Returns the st_ctim field of the internal filestat_t
fn file_attributes(&self) -> u32
Returns the value of the dwFileAttributes field of this metadata. Read more
fn creation_time(&self) -> u64
Returns the value of the ftCreationTime field of this metadata. Read more
fn last_access_time(&self) -> u64
Returns the value of the ftLastAccessTime field of this metadata. Read more
fn last_write_time(&self) -> u64
Returns the value of the ftLastWriteTime field of this metadata. Read more
fn file_size(&self) -> u64
Returns the value of the nFileSize{High,Low} fields of this metadata. Read more
fn volume_serial_number(&self) -> Option<u32>
Returns the value of the dwVolumeSerialNumber field of this metadata. Read more
fn number_of_links(&self) -> Option<u32>
Returns the value of the nNumberOfLinks field of this metadata. Read more
fn file_index(&self) -> Option<u64>
Returns the value of the nFileIndex{Low,High} fields of this metadata. Read more
Auto Trait Implementations
impl RefUnwindSafe for Metadata
impl Send for Metadata
impl Sync for Metadata
impl Unpin for Metadata
impl UnwindSafe for Metadata
Blanket Implementations
impl<T> From<T> for T
pub fn from(t: T) -> T
Performs the conversion.
pub fn into(self) -> U
Performs the conversion.
type Owned = T
The resulting type after obtaining ownership.
pub fn to_owned(&self) -> T
Creates owned data from borrowed data, usually by cloning. Read more
pub fn clone_into(&self, target: &mut T)
toowned_clone_into #41263)recently added
Uses borrowed data to replace owned data, usually by cloning. Read more
type Error = Infallible
The type returned in the event of a conversion error.
pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>
Performs the conversion.
type Error = <U as TryFrom<T>>::Error
The type returned in the event of a conversion error.
pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>
Performs the conversion.
© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/fs/struct.Metadata.html