.IR hash ]
.RI [ file
\&...]
+.br
+.B fshash
+.RB \-u
+.B \-c
+.I cache
+.RB [ \-H
+.IR hash ]
+.RI [ dir ]
.SH DESCRIPTION
The
.B fshash
.BR hashlib .
This option may be omitted: if it is, then the hash is read from the
cache file; if there is no cache file either, then an error is reported.
+.TP
+.B \-u, \-\-udiff
+Rather than produce a manifest, read a unified
+.BR diff (1)
+from standard input, and clear from the cache all files mentioned as
+being different. Filenames in the diff are considered relative to
+.I dir ,
+defaulting to the current working directory.
.PP
Positional arguments are interpreted as files and directories to be
processed, in order. A directory name which ends in
object type and any special information about it, in square brackets,
and padded with spaces so as to take the same width as a hash; see
below for details.
-as follows.
.hP 2.
A `virtual inode identifier': a string which will be the same in two
lines if and only if they represent hard links to the same underlying