tail(1) tail(1)
NAME
tail - deliver the last part of a file
SYNOPSIS
tail [-f][-c number | -n number] [file]
tail _[number][c|l|b][f|r] [file]
DESCRIPTION
tail copies the named file to the standard output beginning at
a designated place. If no file is named, the standard input
is used.
tail processes supplementary code set characters according to
the locale specified in the LC_CTYPE environment variable [see
LANG on environ(5)], except that multibyte characters may be
split, and so not be displayed correctly, when the -b or -c
options are specified.
OPTIONS
-c number
If number has no sign, or has a negative sign (-), tail
will start copying at the absolute value of number bytes
from the end of the file. If number has a + in front of
it, copying starts at number bytes from the start of the
file. The origin for the value of number is 1.
Therefore, -c +1 represents the first byte of the file,
and -c -1 the last byte of the file.
-n number
This option is the same as the -c option, except the
unit is lines rather than bytes. Therefore, -n will
start copying at number lines from the start or end of
the file, rather than number bytes. The origin for the
value of number is 1. Therefore, -n +1 represents the
first line of the file, and -n -1 the last line of the
file.
If neither -c nor -n is specified, the option -n 10 will
be assumed.
-f With the -f (follow) option, if the input is not a pipe,
the program will not terminate after the line of the
input file has been copied, but will enter an endless
loop, wherein it sleeps for a second and then attempts
to read and copy further records from the input file.
Thus it may be used to monitor the growth of a file that
Copyright 1994 Novell, Inc. Page 1
tail(1) tail(1)
is being written by some other process.
_[number][c|l|b][f|r]
If +number, copying begins at distance number from the
beginning of the input. If -number, copying begins at
distance number from the end of the input. If number is
null, the value 10 is assumed. Number is counted in
units of lines, blocks, or bytes, according to the
appended option l, b, or c. When no units are
specified, counting is by lines.
If number is not null, then:
+numberc is equivalent to -c +number
+numberl is equivalent to -n +number
-numberc is equivalent to -c number or -c -number
-numberl is equivalent to -n number or -n -number
The f option in this synopsis is identical to the normal
-f option.
The r option copies lines from the specified starting
point in the file in reverse order. number is the count
of lines from the end of the file, regardless of the
sign. The default for r is to print the entire file in
reverse order.
The r and f options are mutually exclusive.
EXAMPLES
The command:
tail -f fred
will print the last ten lines of the file fred, followed by
any lines that are appended to fred between the time tail is
initiated and killed. As another example, the command:
tail -f -c 15 fred
will print the last 15 bytes of the file fred, followed by any
lines that are appended to fred between the time tail is
initiated and killed.
FILES
/usr/lib/locale/locale/LC_MESSAGES/uxcore.abi
language-specific message file [See LANG on environ
(5).]
Copyright 1994 Novell, Inc. Page 2
tail(1) tail(1)
REFERENCES
cat(1), dd(1M), head(1), more(1), pg(1), tail(1)
NOTICES
Tails relative to the end of the file are stored in a buffer,
and thus are limited in length. Various kinds of anomalous
behavior may happen with character special files. The tail
command will only tail the last {LINE_MAX}*10 bytes of a file
regardless of its line count.
The second synopsis form (_[number][c|l|b][f|r]) may be
removed in future releases, and so should be avoided.
Copyright 1994 Novell, Inc. Page 3