Linux Command


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

-c, --bytes=K
output the last K bytes; alternatively, use -c +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 --fol-
low=descriptor are equivalent

-F same as --follow=name --retry

-n, --lines=K
output the last K lines, instead of the last 10; or use -n +K to
output lines starting with the Kth

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). With
inotify, this option is rarely useful.

with -f, terminate after process ID, PID dies

-q, --quiet, --silent
never output headers giving file names

keep trying to open a file even when it is or becomes inaccessi-
ble; 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

With inotify and --pid=P, check process P at least once every N

-v, --verbose
always output headers giving file names

--help display this help and exit

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, other-
wise, 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 descrip-
tor (e.g., log rotation). Use --follow=name in that case. That causes
tail to track the named file in a way that accommodates renaming,
removal and creation.

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