$NetBSD: patch-ab,v 1.7 2022/03/25 10:30:25 wiz Exp $

Patch digest man page for rdigest functionality

--- digest.1.orig	2022-03-25 10:29:21.419832305 +0000
+++ digest.1
@@ -24,20 +24,21 @@
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
 .Dd September 28, 2021
-.Dt DIGEST 1
+.Dt RDIGEST 1
 .Os
 .Sh NAME
-.Nm digest
-.Nd calculate message digests
+.Nm rdigest
+.Nd calculate message digests of files and directories
 .Sh SYNOPSIS
 .Nm
 .Op Fl "Vt"
+.Op Fl x Ar directory
 .Ar algorithm
 .Op Ar
 .Sh DESCRIPTION
 The
 .Nm
-utility calculates message digests of files or,
+utility calculates message digests of files, directories, or,
 if no file is specified, standard input.
 .Pp
 It can also run self tests via the
@@ -46,6 +47,12 @@ command line option; the only self tests
 for the
 .Dv SHA3
 set of digests.
+The
+.Fl x
+option can be used as many times as required to indicate directories
+not to be included in a directory's hash.
+This allows you to skip, eg, CVS subdirectories in a given tree, which
+can have relatively volatile contents not pertinent to the hash.
 .Pp
 The
 .Fl V
@@ -119,12 +126,32 @@ utility is a simple wrapper for the vari
 algorithm implementations, which are located in the standard
 C library, and was designed to be scalable as new message digest
 algorithms are developed.
+The checksum for a directory is implemented as the hash over a list of
+one or two hashes for each of the items in the tree.
+.Bl -bullet
+.It
+For a file, the string
+.Dq f \& 
+along with the path make up the data for one hash, and the contents of
+the file is used for the second hash.
+.It
+For a symbolic link, the string
+.Dq l \&
+along with the path to the symbolic link make up the data for one
+hash, and the target of the symbolic link is used for the second hash.
+.It
+For a directory, the string
+.Dq d \&
+along with the path make up the data for one hash.
+There is no second hash for a directory.
+.El
 .Pp
 The
 .Nm
 utility exits 0 on success, and \*[Gt]0 if an error occurs.
 .Sh SEE ALSO
 .Xr cksum 1 ,
+.Xr digest 1 ,
 .Xr md5 3 ,
 .Xr rmd160 3 ,
 .Xr sha1 3
@@ -132,9 +159,13 @@ utility exits 0 on success, and \*[Gt]0 
 The
 .Nm
 utility first appeared in
-.Nx 1.6 .
+.Nx 2.0 .
 .Sh AUTHORS
 The
+.Xr digest 1
+utility was written by Alistair G. Crooks \*[Lt]agc@netbsd.org\*[Gt].
 .Nm
-utility was written by
-.An Alistair G. Crooks Aq Mt agc@netbsd.org .
+was implemented by Andrew Brown \*[Lt]atatat@netbsd.org\*[Gt] as a
+patch to
+.Xr digest 1
+to add recursive capabilities.