On Fri, Aug 26, 2011 at 16:04:57 -0400, Nathan Stratton Treadway wrote:
> I recently noticed a small error in the "Format of the Incremental
> Snapshot Files" node of the GNU tar documentation (e.g.
> http://www.gnu.org/software/tar/manual/html_node/Snapshot-Files.html
> ).
>
> In that node, the description of the Format 0 "nfs" field says
>
> A single plus character (+), if this directory is located on an
> NFS-mounted partition, or a single space otherwise;"
>
> , but based on an old version 0 snapshot file I have lying around as
> well as the "read_incr_db_01" function from incremen.c, I think that if
> the file was not NFS mounted then there is no character at all in that
> field. (That is, on lines for non-NFS directories, the first character
> in the line is simply the first character of the device number field...)
Attached is a patch to the snapshot.texi source file that attempts to
clarify this (as well as give more precise information about which
versions of tar used each format).
Nathan
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Nathan Stratton Treadway - [email protected] - Mid-Atlantic region
Ray Ontko & Co. - Software consulting services - http://www.ontko.com/
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--- tar_orig/doc/snapshot.texi 2011-09-17 18:12:04.039667522 -0400
+++ tar/doc/snapshot.texi 2011-09-18 17:06:49.329667142 -0400
@@ -11,11 +11,11 @@
@GNUTAR{} version @value{VERSION} supports three snapshot file
formats. The first format, called @dfn{format 0}, is the one used by
-@GNUTAR{} versions up to 1.15.1. The second format, called @dfn{format
-1} is an extended version of this format, that contains more metadata
-and allows for further extensions. It was used by version
-1.15.1. Starting from version 1.16 and up to @value{VERSION}, the
-@dfn{format 2} is used.
+@GNUTAR{} versions up to and including 1.15.1. The second format, called
+@dfn{format 1} is an extended version of this format, that contains more
+metadata and allows for further extensions. It was used by alpha release
+version 1.15.90. For alpha version 1.15.91 and stable releases
+version 1.16 up through @value{VERSION}, the @dfn{format 2} is used.
@GNUTAR{} is able to read all three formats, but will create
snapshots only in format 2.
@@ -33,7 +33,7 @@
following format:
@smallexample
-@var{nfs}@var{dev} @var{inode} @var{name}
+[@var{nfs}]@var{dev} @var{inode} @var{name}
@end smallexample
@noindent
@@ -42,7 +42,10 @@
@table @var
@item nfs
A single plus character (@samp{+}), if this directory is located on
-an @acronym{NFS}-mounted partition, or a single space otherwise;
+an @acronym{NFS}-mounted partition, otherwise empty.
+
+(That is, for non-NFS directories, the first character on the
+description line contains the start of the @var{dev} field.)
@item dev
Device number of the directory;
