ApplyLayer parses a diff in the standard layer format from `layer`, and applies it to the directory `dest`.

ApplyUncompressedLayer parses a diff in the standard layer format from `layer`, and applies it to the directory `dest`.

CopyFileWithTar emulates the behavior of the 'cp' command-line for a single file.

CopyWithTar creates a tar archive of filesystem path `src`, and unpacks it at filesystem path `dst`.

TarUntar is a convenience function which calls Tar and Untar, with the output of one piped into the other.

Untar reads a stream of bytes from `archive`, parses it as a tar archive, and unpacks it into the directory at `dest`.

UntarPath is a convenience function which looks for an archive at filesystem path `src`, and unpacks it at `dst`.

UntarUncompressed reads a stream of bytes from `archive`, parses it as a tar archive, and unpacks it into the directory at `dest`.