rev: (man) add note about limitations

Addresses: https://github.com/karelzak/util-linux/issues/972
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/text-utils/rev.1 b/text-utils/rev.1
index e6e1f0912d9683d9d209f586dbc8a505b5f719f3..3b45bfa6a7f2df394fe975a4aefa849a8ceb6944 100644 (file)
--- a/text-utils/rev.1
+++ b/text-utils/rev.1
@@ -43,6 +43,10 @@ The
 .B rev
 utility copies the specified files to standard output, reversing the order of
 characters in every line.  If no files are specified, standard input is read.
+.PP
+This utility is a line-oriented tool and it uses in-memory allocated buffer
+for a whole wide-char line.  If the input file is huge and without line breaks
+than allocate the memory for the file may be unsuccessful.
 .SH OPTIONS
 .TP
 \fB\-V\fR, \fB\-\-version\fR