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author | rgrimes <rgrimes@FreeBSD.org> | 1994-05-27 12:33:43 +0000 |
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committer | rgrimes <rgrimes@FreeBSD.org> | 1994-05-27 12:33:43 +0000 |
commit | f9ab90d9d6d02989a075d0f0074496d5b1045e4b (patch) | |
tree | add7e996bac5289cdc55e6935750c352505560a9 /usr.bin/tail/tail.1 | |
parent | be22b15ae2ff8d7fe06b6e14fddf0c5b444a95da (diff) | |
download | FreeBSD-src-f9ab90d9d6d02989a075d0f0074496d5b1045e4b.zip FreeBSD-src-f9ab90d9d6d02989a075d0f0074496d5b1045e4b.tar.gz |
BSD 4.4 Lite Usr.bin Sources
Diffstat (limited to 'usr.bin/tail/tail.1')
-rw-r--r-- | usr.bin/tail/tail.1 | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/usr.bin/tail/tail.1 b/usr.bin/tail/tail.1 new file mode 100644 index 0000000..02bfba8 --- /dev/null +++ b/usr.bin/tail/tail.1 @@ -0,0 +1,165 @@ +.\" 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. +.\" +.\" Redistribution and use in source and binary forms, with or without +.\" modification, are permitted provided that the following conditions +.\" are met: +.\" 1. Redistributions of source code must retain the above copyright +.\" notice, this list of conditions and the following disclaimer. +.\" 2. Redistributions in binary form must reproduce the above copyright +.\" notice, this list of conditions and the following disclaimer in the +.\" documentation and/or other materials provided with the distribution. +.\" 3. All advertising materials mentioning features or use of this software +.\" must display the following acknowledgement: +.\" This product includes software developed by the University of +.\" California, Berkeley and its contributors. +.\" 4. Neither the name of the University nor the names of its contributors +.\" may be used to endorse or promote products derived from this software +.\" without specific prior written permission. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND +.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE +.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL +.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS +.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) +.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY +.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF +.\" SUCH DAMAGE. +.\" +.\" @(#)tail.1 8.1 (Berkeley) 6/6/93 +.\" +.Dd June 6, 1993 +.Dt TAIL 1 +.Os BSD 4 +.Sh NAME +.Nm tail +.Nd display the last part of a file +.Sh SYNOPSIS +.Nm tail +.Op Fl f Li | Fl r +.Oo +.Fl b Ar number | +.Fl c Ar number | +.Fl n Ar number +.Oc +.Op Ar file ... +.Sh DESCRIPTION +The +.Nm tail +utility displays the contents of +.Ar file +or, by default, its standard input, to the standard output. +.Pp +The display begins at a byte, line or 512-byte block location in the +input. +Numbers having a leading plus (``+'') sign are relative to the beginning +of the input, for example, +.Dq -c +2 +starts the display at the second +byte of the input. +Numbers having a leading minus (``-'') sign or no explicit sign are +relative to the end of the input, for example, +.Dq -n 2 +displays the last two lines of the input. +The default starting location is +.Dq -n 10 , +or the last 10 lines of the input. +.Pp +The options are as follows: +.Bl -tag -width Ds +.It Fl b Ar number +The location is +.Ar number +512-byte blocks. +.It Fl c Ar number +The location is +.Ar number +bytes. +.It Fl f +The +.Fl f +option causes +.Nm tail +to not stop when end of file is reached, but rather to wait for additional +data to be appended to the input. +The +.Fl f +option is ignored if the standard input is a pipe, but not if it is a FIFO. +.It Fl n Ar number +The location is +.Ar number +lines. +.It Fl r +The +.Fl r +option causes the input to be displayed in reverse order, by line. +Additionally, this option changes the meaning of the +.Fl b , +.Fl c +and +.Fl n +options. +When the +.Fl r +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. +The default for the +.Fl r +option is to display all of the input. +.El +.Pp +If more than a single file is specified, each file is preceded by a +header consisting of the string +.Dq ==> XXX <== +where +.Dq XXX +is the name of the file. +.Pp +The +.Nm tail +utility exits 0 on success, and >0 if an error occurs. +.Sh SEE ALSO +.Xr cat 1 , +.Xr head 1 , +.Xr sed 1 +.Sh STANDARDS +The +.Nm tail +utility is expected to be a superset of the POSIX 1003.2 +specification. +In particular, the +.Fl b +and +.Fl r +options are extensions to that standard. +.Pp +The historic command line syntax of +.Nm tail +is supported by this implementation. +The only difference between this implementation and historic versions +of +.Nm tail , +once the command line syntax translation has been done, is that the +.Fl b , +.Fl c +and +.Fl n +options modify the +.Fl r +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'') +would ignore the +.Fl c +option and display the last 4 lines of the input. +.Sh HISTORY +A +.Nm tail +command appeared in +.At v7 . |