Blob


1 .TH TAIL 1
2 .SH NAME
3 tail \- deliver the last part of a file
4 .SH SYNOPSIS
5 .B tail
6 [
7 .BR +- \fInumber\fP[ lbc ][ rf ]
8 ]
9 [
10 .I file
11 ]
12 .PP
13 .B tail
14 [
15 .B -fr
16 ]
17 [
18 .B -n
19 .I nlines
20 ]
21 [
22 .B -c
23 .I nbytes
24 ]
25 [
26 .I file
27 ]
28 .SH DESCRIPTION
29 .I Tail
30 copies the named file to the standard output beginning
31 at a designated place.
32 If no file is named, the standard input is copied.
33 .PP
34 Copying begins at position
35 .BI + number
36 measured from the beginning, or
37 .BI - number
38 from the end of the input.
39 .I Number
40 is counted in lines, 1K blocks or bytes,
41 according to the appended flag
42 .LR l ,
43 .LR b ,
44 or
45 .LR c .
46 Default is
47 .B -10l
48 (ten ell).
49 .PP
50 The further flag
51 .L r
52 causes tail to print lines from the end of the file in reverse order;
53 .L f
54 (follow) causes
55 .IR tail ,
56 after printing to the end, to keep watch and
57 print further data as it appears.
58 .PP
59 The second syntax is that promulgated by POSIX, where
60 the
61 .I numbers
62 rather than the options are signed.
63 .SH EXAMPLES
64 .TP
65 .B tail file
66 Print the last 10 lines of a file.
67 .TP
68 .B tail +0f file
69 Print a file, and continue to watch
70 data accumulate as it grows.
71 .TP
72 .B sed 10q file
73 Print the first 10 lines of a file.
74 .SH SOURCE
75 .B \*9/src/cmd/tail.c
76 .SH BUGS
77 Tails relative to the end of the file
78 are treasured up in a buffer, and thus
79 are limited in length.
80 .PP
81 According to custom, option
82 .BI + number
83 counts lines from 1, and counts
84 blocks and bytes from 0.
85 .PP
86 .I Tail
87 is ignorant of UTF.