tail — output the last part of files
tail
[OPTION
...] [FILE
...]
Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is −, read standard input.
Mandatory arguments to long options are mandatory for short options too.
−−retry
keep trying to open a file even if it is
inaccessible when tail starts or if it becomes
inaccessible later; useful when following by name,
i.e., with −−follow
=name
−c
, −−bytes
=N
output the last N bytes; alternatively, use +N to output bytes starting with the Nth of each file
−f
, −−follow[=
{name|descriptor}]output appended data as the file grows; −f
, −−follow
, and −−follow
=descriptor
are
equivalent
−F
same as −−follow
=name
−−retry
−n
, −−lines
=N
output the last N lines, instead of the last 10; or use +N to output lines starting with the Nth
−−max−unchanged−stats
=N
with −−follow
=name
, reopen a FILE
which has not changed size after N (default 5)
iterations to see if it has been unlinked or renamed
(this is the usual case of rotated log files)
−−pid
=PID
with −f
, terminate
after process ID, PID dies
−q
, −−quiet
, −−silent
never output headers giving file names
−s
, −−sleep−interval
=S
with −f
, sleep for
approximately S seconds (default 1.0) between
iterations.
−v
, −−verbose
always output headers giving file names
−−help
display this help and exit
−−version
output version information and exit
If the first character of N (the number of bytes or lines) is a `+', print beginning with the Nth item from the start of each file, otherwise, print the last N items in the file. N may have a multiplier suffix: b 512, k 1024, m 1024*1024.
With −−follow
(−f
), tail defaults to
following the file descriptor, which means that even if a
tail'ed file is renamed, tail will continue to track its end.
This default behavior is not desirable when you really want
to track the actual name of the file, not the file descriptor
(e.g., log rotation). Use −−follow
=name
in that case. That
causes tail to track the named file by reopening it
periodically to see if it has been removed and recreated by
some other program.
The full documentation for tail is maintained as a Texinfo
manual. If the info
and tail
programs are properly installed at your site, the command
info tail
should give you access to the complete manual.
COPYRIGHT |
---|
Copyright © 2007 Free Software Foundation, Inc. This is free software. You may redistribute copies of it under the terms of the GNU General Public License <http://www.gnu.org/licenses/gpl.html>. There is NO WARRANTY, to the extent permitted by law. |