X-Git-Url: https://git.dogcows.com/gitweb?a=blobdiff_plain;f=doc%2Ftar.texi;h=979e2427954ef2d199774456a8325cf7608b9c4a;hb=f0a1f78196f75678424712ac36f0a4a46e3e5658;hp=ddfa055e47e570a1c00956e3d9b3f71a62274351;hpb=751b61ab25ddc03510a695d55a916943aea2f6f0;p=chaz%2Ftar

diff --git a/doc/tar.texi b/doc/tar.texi
index ddfa055..979e242 100644
--- a/doc/tar.texi
+++ b/doc/tar.texi
@@ -2804,6 +2804,21 @@ Specifies that @command{tar} should ask the user for confirmation before
 performing potentially destructive options, such as overwriting files.
 @xref{interactive}.
 
+@opsummary{--keep-directory-symlink}
+@item --keep-directory-symlink
+
+This option changes the behavior of tar when it encounters a symlink
+with the same name as the directory that it is about to extract.  By
+default, in this case tar would first remove the symlink and then
+proceed extracting the directory.
+
+The @option{--keep-directory-symlink} option disables this behavior
+and instructs tar to follow symlinks to directories when extracting
+from the archive.
+
+It is mainly intended to provide compatibility with the Slackware
+installation scripts.
+
 @opsummary{keep-newer-files}
 @item --keep-newer-files
 
@@ -3946,10 +3961,10 @@ e.g.:
 @end smallexample
 
 The @samp{%s} and @samp{%u} in the above example are
-@dfn{meta-characters}.  The @samp{%s} meta-character is replaced with
+@dfn{format specifiers}.  The @samp{%s} specifier is replaced with
 the @dfn{type} of the checkpoint: @samp{write} or
 @samp{read} (or a corresponding translated version in locales other
-than @acronym{POSIX}).  The @samp{%u} meta-character is replaced with
+than @acronym{POSIX}).  The @samp{%u} specifier is replaced with
 the ordinal number of the checkpoint.  Thus, the above example could
 produce the following output when used with the @option{--create}
 option:
@@ -3960,7 +3975,46 @@ tar: Hit write checkpoint #20
 tar: Hit write checkpoint #30
 @end smallexample
 
-Aside from meta-character expansion, the message string is subject to
+The complete list of available format specifiers follows:
+
+@table @samp
+@item %s
+Print type of the checkpoint (@samp{write} or @samp{read}).
+
+@item %u
+Print number of the checkpoint.
+
+@item %T
+Print number of bytes transferred so far and approximate transfer
+speed.  The number is preceded by @samp{W:}, when writing and by
+@samp{R:} when reading.  If @command{tar} is performing delete
+operation (@pxref{delete}), three numbers are printed: number of bytes
+read, written and deleted, each of them prefixed by @samp{R:},
+@samp{W:} and @samp{D:} correspondingy.  For example:
+
+@example
+$ @kbd{tar --delete -f f.tar --checkpoint-action=echo="#%u: %T" main.c}
+tar: #1: R: 0 (0B, ?/s),W: 0 (0B, ?/s),D: 0
+tar: #2: R: 10240 (10KiB, 19MiB/s),W: 0 (0B, 0B/s),D: 10240
+@end example
+
+@noindent
+See also the @samp{totals} action, described below.
+
+@item %@{@var{fmt}@}t
+Output current local time using @var{fmt} as format for @command{strftime}
+(@pxref{strftime, strftime,,strftime(3), strftime(3) man page}).  The
+@samp{@{@var{fmt}@}} part is optional.  If not present, the default
+format is @samp{%c}, i.e. the preferred date and time representation
+for the current locale.
+
+@item %@{@var{n}@}*
+Pad output with spaces to the @var{n}th column.  If the
+@samp{@{@var{n}@}} part is omitted, the current screen width
+is assumed.
+@end table
+
+Aside from format expansion, the message string is subject to
 @dfn{unquoting}, during which the backslash @dfn{escape sequences} are
 replaced with their corresponding @acronym{ASCII} characters
 (@pxref{escape sequences}).  E.g. the following action will produce an
@@ -3987,9 +4041,23 @@ following action will print the checkpoint message at the same screen
 line, overwriting any previous message:
 
 @smallexample
---checkpoint-action="ttyout=\rHit %s checkpoint #%u"
+--checkpoint-action="ttyout=Hit %s checkpoint #%u%*\r"
 @end smallexample
 
+@noindent
+Notice the use of @samp{%*} specifier to clear out any eventual
+remains of the prior output line.  As as more complex example,
+consider this:
+
+@smallexample
+--checkpoint-action=ttyout='%@{%Y-%m-%d %H:%M:%S@}t (%d sec): #%u, %T%*\r'
+@end smallexample
+
+@noindent
+This prints the current local time, number of seconds expired since
+tar was started, the checkpoint ordinal number, transferred bytes and
+average computed I/O speed.
+
 @cindex @code{dot}, checkpoint action
 Another available checkpoint action is @samp{dot} (or @samp{.}).  It
 instructs @command{tar} to print a single dot on the standard listing
@@ -4004,6 +4072,12 @@ For compatibility with previous @GNUTAR{} versions, this action can
 be abbreviated by placing a dot in front of the checkpoint frequency,
 as shown in the previous section.
 
+@cindex @code{totals}, checkpoint action
+The @samp{totals} action prints the total number of bytes transferred
+so far.  The format of the data is the same as for the
+@option{--totals} option (@pxref{totals}).  See also @samp{%T} format
+specifier of the @samp{echo} or @samp{ttyout} action.
+
 @cindex @code{sleep}, checkpoint action
 Yet another action, @samp{sleep}, pauses @command{tar} for a specified
 amount of seconds.  The following example will stop for 30 seconds at each
@@ -4221,6 +4295,10 @@ tar (child): trying gzip
 This means that @command{tar} first tried to decompress
 @file{archive.Z} using @command{compress}, and, when that
 failed, switched to @command{gzip}.
+@kwindex record-size
+@cindex @samp{Record size = %lu blocks}, warning message
+@item record-size
+@samp{Record size = %lu blocks}
 @end table
 
 @subheading Keywords controlling incremental extraction:
@@ -10706,15 +10784,16 @@ When reading an archive, @command{tar} can usually figure out the
 record size on itself.  When this is the case, and a non-standard
 record size was used when the archive was created, @command{tar} will
 print a message about a non-standard blocking factor, and then operate
-normally.  On some tape devices, however, @command{tar} cannot figure
-out the record size itself.  On most of those, you can specify a
-blocking factor (with @option{--blocking-factor}) larger than the
-actual blocking factor, and then use the @option{--read-full-records}
-(@option{-B}) option.  (If you specify a blocking factor with
-@option{--blocking-factor} and don't use the
-@option{--read-full-records} option, then @command{tar} will not
-attempt to figure out the recording size itself.)  On some devices,
-you must always specify the record size exactly with
+normally@footnote{If this message is not needed, you can turn it off
+using the @option{--warning=no-record-size} option.}.  On some tape
+devices, however, @command{tar} cannot figure out the record size
+itself.  On most of those, you can specify a blocking factor (with
+@option{--blocking-factor}) larger than the actual blocking factor,
+and then use the @option{--read-full-records} (@option{-B}) option.
+(If you specify a blocking factor with @option{--blocking-factor} and
+don't use the @option{--read-full-records} option, then @command{tar}
+will not attempt to figure out the recording size itself.)  On some
+devices, you must always specify the record size exactly with
 @option{--blocking-factor} when reading, because @command{tar} cannot
 figure it out.  In any case, use @option{--list} (@option{-t}) before
 doing any extractions to see whether @command{tar} is reading the archive