TAIL
Section: User Commands (1)
Updated: December 2009
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NAME
tail - output the last part of files
SYNOPSIS
tail
[OPTION]... [FILE]...
DESCRIPTION
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.
- -c, --bytes=K
-
output the last K bytes; alternatively, use +K to
output bytes starting with the Kth 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=K
-
output the last K lines, instead of the last 10;
or use +K to output lines starting with the Kth
- --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
- --retry
-
keep trying to open a file even when it is or
becomes inaccessible; useful when following by
name, i.e., with --follow=name
- -s, --sleep-interval=N
-
with -f, sleep for approximately N 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 K (the number of bytes or lines) is a `+',
print beginning with the Kth item from the start of each file, otherwise,
print the last K items in the file. K may have a multiplier suffix:
b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024,
GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y.
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.
AUTHOR
Written by Paul Rubin, David MacKenzie, Ian Lance Taylor,
and Jim Meyering.
REPORTING BUGS
Report tail bugs to bug-coreutils@gnu.org
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
COPYRIGHT
Copyright © 2009 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
SEE ALSO
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 coreutils aqtail invocationaq
should give you access to the complete manual.