R.from.shell            Using R From a Shell
as.relative.path        Make a Path Relative to Another Path
check.path              Check 'this.path()' is Functioning Correctly
here                    Construct Path to File, Beginning with
                        'this.dir()'
this.path               Determine Executing Script's Filename
this.path-defunct       Defunct Functions in Package *this.path*
this.path-package       Get Executing Script's Path, from 'RStudio',
                        'Rgui', 'Rscript' (Shells Including Windows
                        Command-Line / / Unix Terminal), and 'source'
this.path2              Determine Executing Script's Filename
