Function realpath_ext::realpath_raw[−][src]

pub fn realpath_raw(
    path: &[u8], 
    buf: &mut [u8], 
    flags: RealpathFlags
) -> Result<usize, i32>

Canonicalize the given path.

This function resolves the path specified by path, storing the result in buf. On success, the length of the resolved path is returned; on error, an OS error code is returned.

If flags is specified as RealpathFlags::empty(), this is roughly equivalent to the libc’s realpath(). Otherwise, the given flags modify aspects of path resolution.

This function does not allocate any memory. It will only call the following C functions:

  • sysconf(_SC_SYMLOOP_MAX)
  • readlink()
  • stat() (only if it needs to be verified that the path is a directory)
  • getcwd() (only if the given path is relative and does not contain a reference to an absolute symbolic link)

Example usage:

let mut buf = [0; libc::PATH_MAX as usize];
let n = realpath_raw(b"///", &mut buf, RealpathFlags::empty()).unwrap();
assert_eq!(&buf[..n], b"/");

The returned path will ALWAYS be absolute.

Errors

This function may fail with the following errors:

  • ENAMETOOLONG: Either:

    1. The given buf is not long enough to store the canonicalized path, or
    2. The current working directory cannot be represented in a buffer of length PATH_MAX, or
    3. An intermediate result created by combining any symbolic link paths exceeded the system PATH_MAX. (Note that the actual limit is slightly higher than PATH_MAX to account for storage overhead; this should not be relied upon.)

  • EINVAL: The given path contains a NUL byte (not allowed in *nix paths).

  • ELOOP: Too many symbolic links were encounted during resolution.

    This function will use sysconf() to check the system’s SYMLOOP_MAX value to determine the limit. If that fails (for example, it always fails on glibc), this function will fall back on a limit of 40 (which is Linux’s limit).

  • ENOENT/EACCES/ENOTDIR: The given path (or a component of it) does not exist, is inaccessible, or is not a directory (respectively).

    ENOENT and EACCES may also be returned if getcwd() had to be called (see above for the conditions in which this may be necessary) and the path to the current directory cannot be obtained.

    (Note that these errors may be ignored depending on the specified flags.)

  • EIO: An I/O error occurred while interacting with the filesystem.