blkid: (man) add note about udev encoding

Addresses: https://github.com/karelzak/util-linux/issues/632
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/misc-utils/blkid.8 b/misc-utils/blkid.8
index 8fafa38bff9ac7c7d1a0d3a738341fa8bdb65ece..13b5edb4d79ed36feb5a4253c5d26c06f706dcca 100644 (file)
--- a/misc-utils/blkid.8
+++ b/misc-utils/blkid.8
@@ -194,11 +194,16 @@ and \fB\-\-uuid\fR options
 .TP
 .B udev
 print key="value" pairs for easy import into the udev environment; the keys are
-prefixed by ID_FS_ or ID_PART_ prefixes
+prefixed by ID_FS_ or ID_PART_ prefixes.  The value may be modified to be
+safe for udev environment; allowed is plain ASCII, hex-escaping and valid UTF-8,
+everything else (including whitespaces) is replaced with '_'. The keys with
+_ENC postfix use hex-escaping for unsafe chars.
 
 The udev output returns the ID_FS_AMBIVALENT tag if more superblocks are detected,
 and ID_PART_ENTRY_* tags are always returned for all partitions including empty
-partitions.  This output format is \fBDEPRECATED\fR.
+partitions.
+
+This output format is \fBDEPRECATED\fR.
 .TP
 .B export
 print key=value pairs for easy import into the environment; this output format