Linux in a Nutshell, 6th Edition

Name

tail

Synopsis

tail [options] [files]

Print the last 10 lines of each named file on standard output. Print from standard input with no filename or with -. If more than one file is specified, the output includes a header at the beginning of each file:

==> filename <==

For options that take the number of bytes or lines as an argument, you can prepend a plus sign (+) to num to begin printing with the numth item. These options can also specify a block size:

b

512 bytes

K

1 kilobyte

M

1 megabyte

G

1 gigabyte

Options

-c num, --bytes num

Print the last num bytes.

-f, --follow[=name|descriptor]

Don’t quit at the end of file; “follow” file as it grows and end when the user presses Ctrl-C. Following by file descriptor is the default, so -f, --follow, and --follow=descriptor are equivalent. Use --follow=name to track the actual name of a file even if the file is renamed, as with a rotated logfile.

-F

Identical to --follow=name --retry.

--help

Print a help message and exit.

-n num, --lines=num

Print the last num lines.

--max-unchanged-stats=num

Used with --follow=name to reopen a file whose size hasn’t changed after num iterations (default 5), to see if it has been unlinked or renamed (as with rotated logfiles).

--pid=pid

Used with -f to end when process ID pid dies.

-q, --quiet, --silent

Suppress filename headers.

--retry

Keep trying to open a file even if it isn’t accessible when tail starts or if it becomes inaccessible later. Useful with --follow=name.

-s sec, --sleep-interval=sec

With -f, sleep approximately sec seconds ...