Validation of the files or directories
Function to check if the full path (file or directory) exists. 
a character vector of full path name.
This function produces a character vector of the file or directory name defined on the \code{path} argument.
A character vector containing the name of the file or directory. If the path does not exist, it will return an error message. 
Daniela Cassol
file <- system.file("extdata/", "targets.txt", package="systemPipeR")
\keyword{ utilities }