1.\" Copyright (c) 1980, 1990, 1991 Regents of the University of California. 2.\" All rights reserved. 3.\" 4.\" This code is derived from software contributed to Berkeley by 5.\" the Institute of Electrical and Electronics Engineers, Inc. 6.\" 7.\" %sccs.include.redist.roff% 8.\" 9.\" @(#)tail.1 6.7 (Berkeley) 07/21/91 10.\" 11.Dd 12.Dt TAIL 1 13.Os BSD 4 14.Sh NAME 15.Nm tail 16.Nd display the last part of a file 17.Sh SYNOPSIS 18.Nm tail 19.Op Fl f Li | Fl r 20.Oo 21.Fl b Ar number | 22.Fl c Ar number | 23.Fl n Ar number 24.Oc 25.Op Ar file 26.Sh DESCRIPTION 27The 28.Nm tail 29utility displays the contents of 30.Ar file 31or, by default, its standard input, to the standard output. 32.Pp 33The display begins at an offset from either the beginning or end 34of the input. 35Offsets may be specified in terms of bytes, lines or 512-byte blocks. 36Numbers having a leading plus (``+'') sign are relative to the beginning 37of the input. 38Numbers having a leading minus (``-'') sign or no explicit sign are 39relative to the end of the input. 40All offsets are 1 based, i.e. ``-c +1'' skips a single byte of the 41input. 42The default offset is ``-n 10'', or 10 lines from the end of the 43input. 44.Pp 45The options are as follows: 46.Bl -tag -width Ds 47.It Fl b Ar number 48The offset is 49.Ar number 50512-byte blocks. 51.It Fl c Ar number 52The offset is 53.Ar number 54bytes. 55.It Fl f 56The 57.Fl f 58option causes 59.Nm tail 60to not stop when end of file is reached, but rather to wait for additional 61data to be appended to the input. 62The 63.Fl f 64option is ignored on pipes but not on FIFO's. 65.It Fl n Ar number 66The offset is 67.Ar number 68lines. 69.It Fl r 70The 71.Fl r 72option causes the input to be displayed in reverse order, by line. 73Additionally, this option changes the meaning of the 74.Fl b , 75.Fl c 76and 77.Fl n 78options. 79When the 80.Fl r 81option is specified, these options specify the number of bytes, lines 82or 512-byte blocks to display, instead of the bytes, lines or blocks 83from the beginning or end of the input from which to begin the display. 84The default for the 85.Fl r 86option is to display all of the input. 87.El 88.Pp 89The 90.Nm tail 91utility exits 0 on success, and >0 if an error occurs. 92.Sh SEE ALSO 93.Xr cat 1 , 94.Xr head 1 , 95.Xr sed 1 96.Sh STANDARDS 97The 98.Nm tail 99utility is expected to be a superset of the POSIX 1003.2 100specification. 101In particular, the 102.Fl r 103option is an extension to that standard. 104.Sh HISTORY 105A 106.Nm tail 107command appeared in 108.At v7 . 109