CheckDirPermission checks permission on an existing dir.

Exist returns true if a file or directory exists.

GetEnvironment retrieves the value of the environment variable named by the key.

GetOrDefault returns the value or a default value from a map.

GetReplacement returns a string which replace via a map.

IsDirWriteable checks if dir is writable by writing and removing a file to dir.

ParseVersionNum split version from release or tag.

PathExists checks if the target path exist or not.

PrivateDirMode grants owner to make/remove files inside the directory.

PrivateFileMode grants owner to read/write a file.