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35 .\" @(#)tail.1 8.1 (Berkeley) 6/6/93
43 .Nd display the last part of a file
49 .Fl b Ar number | Fl c Ar number | Fl n Ar number
55 utility displays the contents of
57 or, by default, its standard input, to the standard output.
59 The display begins at a byte, line or 512-byte block location in the
61 Numbers having a leading plus
63 sign are relative to the beginning
64 of the input, for example,
66 starts the display at the second
68 Numbers having a leading minus
70 sign or no explicit sign are
71 relative to the end of the input, for example,
73 displays the last two lines of the input.
74 The default starting location is
76 or the last 10 lines of the input.
78 The options are as follows:
79 .Bl -tag -width indent
93 to not stop when end of file is reached, but rather to wait for additional
94 data to be appended to the input.
97 option is ignored if the standard input is a pipe, but not if it is a FIFO.
105 will also check to see if the file being followed has been renamed or rotated.
106 The file is closed and reopened when
108 detects that the filename being read from has a new inode number.
111 option is ignored if reading from standard input rather than a file.
117 Suppresses printing of headers when multiple files are being examined.
121 option causes the input to be displayed in reverse order, by line.
122 Additionally, this option changes the meaning of the
129 option is specified, these options specify the number of bytes, lines
130 or 512-byte blocks to display, instead of the bytes, lines or blocks
131 from the beginning or end of the input from which to begin the display.
134 option is to display all of the input.
137 If more than a single file is specified, each file is preceded by a
138 header consisting of the string
139 .Dq Li "==> " Ns Ar XXX Ns Li " <=="
142 is the name of the file unless
154 utility is expected to be a superset of the
162 options are extensions to that standard.
164 The historic command line syntax of
166 is supported by this implementation.
167 The only difference between this implementation and historic versions
170 once the command line syntax translation has been done, is that the
179 displays the last 4 characters of the last line
180 of the input, while the historic tail (using the historic syntax
184 option and display the last 4 lines of the input.
188 command appeared in PWB UNIX.