list <- list.files() for(i in 1:length(list)){ print(ncol(read.table(list[i], header = FALSE, sep = ""))) } Good luck, Gianandrea -- View this message in context: http://r.789695.n4.nabble.com/Apply-formula-to-several-files-tp4725516p4725520.html Sent from the datatable-help mailing list archive at Nabble.com.