X-Git-Url: https://git.dogcows.com/gitweb?p=chaz%2Ftar;a=blobdiff_plain;f=doc%2Ftar.texi;h=979e2427954ef2d199774456a8325cf7608b9c4a;hp=9fde5a0761f41b7b6aff3e76bb840a8926e8fdaa;hb=f0a1f78196f75678424712ac36f0a4a46e3e5658;hpb=7f21a4d3f55cf36cd6a5cb13bc51e88a68c2e097 diff --git a/doc/tar.texi b/doc/tar.texi index 9fde5a0..979e242 100644 --- a/doc/tar.texi +++ b/doc/tar.texi @@ -3961,10 +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: @@ -3975,7 +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 @@ -4002,9 +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 @@ -4019,6 +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