Hi, Is there any reason why tar() and untar() don't use the same environment variable? Usage: tar(tarfile, files = NULL, compression = c("none", "gzip", "bzip2", "xz"), compression_level = 6, tar = Sys.getenv("tar")) Usage: untar(tarfile, files = NULL, list = FALSE, exdir = ".", compressed = NA, extras = NULL, verbose = FALSE, tar = Sys.getenv("TAR")) Thanks! H. -- Herv? Pag?s Program in Computational Biology Division of Public Health Sciences Fred Hutchinson Cancer Research Center 1100 Fairview Ave. N, M2-B876 P.O. Box 19024 Seattle, WA 98109-1024 E-mail: hpages at fhcrc.org Phone: (206) 667-5791 Fax: (206) 667-1319