Exclude from dump any directory containing a valid cache directory
tag file. @xref{exclude}.
+@opsummary{exclude-ignore}
+@item --exclude-ignore=@var{file}
+Before dumping a directory, @command{tar} checks if it contains
+@var{file}. If so, exclusion patterns are read from this file.
+The patterns affect only the directory itself. @xref{exclude}.
+
+@opsummary{exclude-ignore-recursive}
+@item --exclude-ignore-recursive=@var{file}
+Before dumping a directory, @command{tar} checks if it contains
+@var{file}. If so, exclusion patterns are read from this file.
+The patterns affect the directory and all itssubdirectories.
+@xref{exclude}.
+
@opsummary{exclude-tag}
@item --exclude-tag=@var{file}
Exclude from dump directories and files, that are internal for some
widely used version control systems.
-@xref{exclude,,exclude-vcs}.
+@xref{exclude-vcs}.
+
+@opsummary{exclude-vcs-ignores}
+@item --exclude-vcs-ignores
+Exclude files that match patterns read from VCS-specific ignore
+files. Supported files are: @file{.cvsignore}, @file{.gitignore},
+@file{.bzrignore}, and @file{.hgignore}. The semantics of each file
+is the same as for the corresponding VCS, e.g. patterns read from
+@file{.gitignore} affect the directory and all its subdirectories.
+@xref{exclude-vcs-ignores}.
@opsummary{file}
@item --file=@var{archive}
However, empty lines are OK.
+@cindex VCS, excluding patterns from ignore files
+@cindex VCS, ignore files
+@cindex CVS, ignore files
+@cindex Git, ignore files
+@cindex Bazaar, ignore files
+@cindex Mercurial, ignore files
+When archiving directories that are under some version control system (VCS),
+it is often convenient to read exclusion patterns from this VCS'
+ignore files (e.g. @file{.cvsignore}, @file{.gitignore}, etc.) The
+following options provide such possibilty:
+
+@table @option
+@anchor{exclude-vcs-ignores}
+@opindex exclude-vcs-ignores
+@item --exclude-vcs-ignores
+Before archiving a directory, see if it contains any of the following
+files: @file{cvsignore}, @file{.gitignore}, @file{.bzrignore}, or
+@file{.hgignore}. If so, read ignore patterns from these files.
+
+The patterns are treated much as the corresponding VCS would treat
+them, i.e.:
+
+@table @file
+@findex .cvsignore
+@item .cvsignore
+Contains shell-style globbing patterns that apply only to the
+directory where this file resides. No comments are allowed in the
+file. Empty lines are ignored.
+
+@findex .gitignore
+@item .gitignore
+Contains shell-style globbing patterns. Applies to the directory
+where @file{.gitfile} is located and all its subdirectories.
+
+Any line beginning with a @samp{#} is a comment. Backslash escapes
+the comment character.
+
+@findex .bzrignore
+@item .bzrignore
+Contains shell globbing-patterns and regular expressions (if prefixed
+with @samp{RE:}@footnote{According to the Bazaar docs,
+globbing-patterns are Korn-shell style and regular expressions are
+perl-style. As of @GNUTAR{} version @value{VERSION}, these are
+treated as shell-style globs and posix extended regexps. This will be
+fixed in future releases.}. Patterns affect the directory and all its
+subdirectories.
+
+Any line beginning with a @samp{#} is a comment.
+
+@findex .hgignore
+@item .hgignore
+Contains posix regular expressions@footnote{Support for perl-style
+regexps will appear in future releases.}. The line @samp{syntax:
+glob} switches to shell globbing patterns. The line @samp{syntax:
+regexp} switches back. Comments begin with a @samp{#}. Patterns
+affect the directory and all its subdirectories.
+@end table
+
+@opindex exclude-ignore
+@item --exclude-ignore=@var{file}
+Before dumping a directory, @command{tar} checks if it contains
+@var{file}. If so, exclusion patterns are read from this file.
+The patterns affect only the directory itself.
+
+@opindex exclude-ignore-recursive
+@item --exclude-ignore-recursive=@var{file}
+Same as @option{--exclude-ignore}, except that the patterns read
+affect both the directory where @var{file} resides and all its
+subdirectories.
+@end table
+
@table @option
@cindex version control system, excluding files
@cindex VCS, excluding files
@cindex Arch, excluding files
@cindex Mercurial, excluding files
@cindex Darcs, excluding files
+@anchor{exclude-vcs}
@opindex exclude-vcs
@item --exclude-vcs
Exclude files and directories used by following version control
@subsection Ustar Archive Format
@cindex ustar archive format
-Archive format defined by @acronym{POSIX}.1-1988 specification is called
-@code{ustar}. Although it is more flexible than the V7 format, it
+The archive format defined by the @acronym{POSIX}.1-1988 specification is
+called @code{ustar}. Although it is more flexible than the V7 format, it
still has many restrictions (@pxref{Formats,ustar}, for the detailed
description of @code{ustar} format). Along with V7 format,
@code{ustar} format is a good choice for archives intended to be read
with other implementations of @command{tar}.
-To create archive in @code{ustar} format, use @option{--format=ustar}
-option in conjunction with the @option{--create} (@option{-c}).
+To create an archive in @code{ustar} format, use the @option{--format=ustar}
+option in conjunction with @option{--create} (@option{-c}).
@node gnu
@subsection @acronym{GNU} and old @GNUTAR{} format
SunOS and HP-UX @command{tar} fail to accept archives created using
@GNUTAR{} and containing non-@acronym{ASCII} file names, that
-is, file names having characters with the eight bit set, because they
+is, file names having characters with the eighth bit set, because they
use signed checksums, while @GNUTAR{} uses unsigned
checksums while creating archives, as per @acronym{POSIX} standards. On
-reading, @GNUTAR{} computes both checksums and
-accepts any. It is somewhat worrying that a lot of people may go
+reading, @GNUTAR{} computes both checksums and accepts either of them.
+It is somewhat worrying that a lot of people may go
around doing backup of their files using faulty (or at least
non-standard) software, not learning about it until it's time to
restore their missing files with an incompatible file extractor, or
vice versa.
-@GNUTAR{} computes checksums both ways, and accept
-any on read, so @acronym{GNU} tar can read Sun tapes even with their
+@GNUTAR{} computes checksums both ways, and accepts either of them
+on read, so @acronym{GNU} tar can read Sun tapes even with their
wrong checksums. @GNUTAR{} produces the standard
checksum, however, raising incompatibilities with Sun. That is to
say, @GNUTAR{} has not been modified to
started computing checksums wrongly. When they later realized their
mistake, they merely decided to stay compatible with it, and with
themselves afterwards. Presumably, but I do not really know, HP-UX
-has chosen that their @command{tar} archives to be compatible with Sun's.
+has chosen their @command{tar} archives to be compatible with Sun's.
The current standards do not favor Sun @command{tar} format. In any
case, it now falls on the shoulders of SunOS and HP-UX users to get
a @command{tar} able to read the good archives they receive.
projects / chaz / tar / blobdiff