From 711e034235987f5642ee00841f7c620d2979210f Mon Sep 17 00:00:00 2001 From: Glenn Washburn Date: Wed, 26 Jul 2023 13:50:12 -0500 Subject: [PATCH] docs: A note to cat that hexdump should be used for binary data The cat command should not be used to print binary data because it can show bytes not in the binary data and not show bytes that are in the data, which can lead to confusion. This happens because cat does some processing of the data stream, namely trying to decode substrings as UTF-8. Signed-off-by: Glenn Washburn Reviewed-by: Oskari Pirhonen Reviewed-by: Daniel Kiper --- docs/grub.texi | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/docs/grub.texi b/docs/grub.texi index 3634507ac..b233e28e0 100644 --- a/docs/grub.texi +++ b/docs/grub.texi @@ -4507,6 +4507,12 @@ will be displayed as a simple new line. Otherwise, the carriage return will be displayed as a control character (@samp{}) to make it easier to see when boot problems are caused by a file formatted using DOS-style line endings. + +Note: @command{cat} can be used to view the contents of devices using the +block list syntax (@pxref{Block list syntax}). However, it is not advised +to view binary data because it will try to decode UTF-8 strings, which can +lead to some bytes missing or added in the output. Instead, use the +@command{hexdump} command (@pxref{hexdump}). @end deffn