checksum functions: drop silently_close_connections() *

It appears to have been a fix for a missing close() statement
in the examples (after using writeLines()), rather than a
problem with the function.
It was done to avoid R auto-closing dangling connections with
a warning, a bit later.

R/filemanagement.R

@@ -391,8 +391,7 @@ fileman_up <- function(name,
 #'
 #' The function names were chosen to match those of GNU coreutils.
 #'
-#' The functions use the OpenSSL implementation of the \code{openssl} package,
-#' and silently close file connections.
+#' The functions use the OpenSSL implementation of the \code{openssl} package.
 #' Note that \code{n2khab} will mask
 #' \code{\link[tools:md5sum]{tools::md5sum()}},
 #' which is a standalone implementation.
@@ -412,7 +411,9 @@ fileman_up <- function(name,
 #' file2 <- tempfile()
 #' files <- c(file1, file2)
 #' file.create(files)
-#' writeLines("some text", file(file2))
+#' con <- file(file2)
+#' writeLines("some text", con)
+#' close(con)
 #'
 #' # computing two alternative checksums:
 #' md5sum(files)
@@ -436,7 +437,6 @@ md5sum <- function(files) {
     assert_that_allfiles_exist(files)
     checksums <- map_chr(files, ~paste(md5(file(.))))
     names(checksums) <- basename(files)
-    silently_close_connections()
     return(checksums)
     }
 
@@ -446,7 +446,6 @@ sha256sum <- function(files) {
     assert_that_allfiles_exist(files)
     checksums <- map_chr(files, ~paste(sha256(file(.))))
     names(checksums) <- basename(files)
-    silently_close_connections()
     return(checksums)
 }
 
@@ -460,10 +459,3 @@ assert_that_allfiles_exist <- function(x) {
                              paste0(x[!exist], collapse = "\n")))
 }
 
-#' @keywords internal
-silently_close_connections <- function() {
-    oldopt <- options(warn = -1)[[1]]
-    closeAllConnections()
-    options(warn = oldopt)
-}
-