.\" Copyright (c) 1980, 1990, 1991, 1993
.\" The Regents of the University of California. All rights reserved.
.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
.\" %sccs.include.redist.roff%
.\" @(#)tail.1 8.1 (Berkeley) %G%
.Nd display the last part of a file
utility displays the contents of
or, by default, its standard input, to the standard output.
The display begins at a byte, line or 512-byte block location in the
Numbers having a leading plus (``+'') sign are relative to the beginning
of the input, for example,
starts the display at the second
Numbers having a leading minus (``-'') sign or no explicit sign are
relative to the end of the input, for example,
displays the last two lines of the input.
The default starting location is
or the last 10 lines of the input.
The options are as follows:
to not stop when end of file is reached, but rather to wait for additional
data to be appended to the input.
option is ignored if the standard input is a pipe, but not if it is a FIFO.
option causes the input to be displayed in reverse order, by line.
Additionally, this option changes the meaning of the
option is specified, these options specify the number of bytes, lines
or 512-byte blocks to display, instead of the bytes, lines or blocks
from the beginning or end of the input from which to begin the display.
option is to display all of the input.
If more than a single file is specified, each file is preceded by a
header consisting of the string
utility exits 0 on success, and >0 if an error occurs.
utility is expected to be a superset of the POSIX 1003.2
options are extensions to that standard.
The historic command line syntax of
is supported by this implementation.
The only difference between this implementation and historic versions
once the command line syntax translation has been done, is that the
option, i.e. ``-r -c 4'' displays the last 4 characters of the last line
of the input, while the historic tail (using the historic syntax ``-4cr'')
option and display the last 4 lines of the input.