Improve one-top-level functionality

[chaz/tar] / doc / tar.texi

diff --git a/doc/tar.texi b/doc/tar.texi
index 424617c25846f664a07d983f54e147d212edce99..48c22a36dc6eb0e2bb213528e239934c6316ef70 100644 (file)
--- a/doc/tar.texi
+++ b/doc/tar.texi
@@ -3086,6 +3086,19 @@ Used when creating an archive.  Prevents @command{tar} from recursing into
 directories that are on different file systems from the current
 directory.
 
+@opsummary{one-top-level}
+@item --one-top-level[=@var{dir}]
+Tells @command{tar} to create a new directory beneath the extraction directory
+(or the one passed to @option{-C}) and use it to guard against
+tarbombs.  In the absence of @var{dir} argument, the name of the new directory
+will be equal to the base name of the archive (file name minus the
+archive suffix, if recognized).  Any member names that do not begin
+with that directory name (after 
+transformations from @option{--transform} and
+@option{--strip-components}) will be prefixed with it.  Recognized
+file name suffixes are @samp{.tar}, and any compression suffixes
+recognizable by @xref{--auto-compress}.
+
 @opsummary{overwrite}
 @item --overwrite