CopyFile copies a file from 'from' to 'to', with an attempt to perform a copy & rename to avoid chaos if anything goes wrong partway.

CopyOrLinkFile either copies or hardlinks a file based on the link argument.

EnsureDir ensures that the directory of the given file has been created.

FileExists returns true if the given path exists and is a file.

Glob implements matching using Go's built-in filepath.Glob, but extends it to support Ant-style patterns using **.

IsGlob returns true if the given pattern requires globbing (i.e.

IsPackage returns true if the given directory name is a package (i.e.

IsSameFile returns true if two filenames describe the same underlying file (i.e.

PathExists returns true if the given path exists, as a file or a directory.

Walk implements an equivalent to filepath.Walk.

WalkMode is like Walk but the callback receives an additional type specifying the file mode type.

WriteFile writes data from a reader to the file named 'to', with an attempt to perform a copy & rename to avoid chaos if anything goes wrong partway.

DirPermissions are the default permission bits we apply to directories.