Scripting

NAME
tail – deliver the last part of a file

SYNOPSIS
/usr/bin/tail [ + _s number [lbcr]] [file]

/usr/bin/tail [-lbcr] [file]

/usr/bin/tail [ + _ number [lbcf]] [file]

/usr/bin/tail [-lbcf] [file]

/usr/xpg4/bin/tail  [-f  |  -r]   [-c number  |   -n number]
[file]

/usr/xpg4/bin/tail [ + _ number [l | b | c]  [f]] [file]

/usr/xpg4/bin/tail [ + _ number [l] [f | r] ] [file]

DESCRIPTION
The tail utility copies the named file to the standard  out-
put  beginning  at  a designated place. If no file is named,
the standard input is used.

Copying begins at a point  in  the  file  indicated  by  the
-cnumber, -nnumber, or + _number options (if +number is speci-
fied, begins at  distance  number  from  the  beginning;  if
-number  is  specified, from the end of the input; if number
is NULL, the value 10 is  assumed).  number  is  counted  in
units  of lines or byte according to the -c  or  -n options,
or lines, blocks, or bytes, according to the appended option
l,  b,  or  c.  When  no units are specified, counting is by
lines.

OPTIONS
The following options are supported for  both  /usr/bin/tail
and  /usr/xpg4/bin/tail.  The -r and -f options are mutually
exclusive. If both are specified on the command line, the -f
option is ignored.

-b       Units of blocks.

-c       Units of bytes.

-f       Follow. If the input-file is not a pipe,  the  pro-
gram  does  not  terminate  after  the  line of the
input-file has been copied, but enters  an  endless
loop,  wherein  it  sleeps  for  a  second and then
attempts to read and copy further records from  the
input-file.  Thus  it  can  be  used to monitor the
growth of a file that  is  being  written  by  some
other process.

-l       Units of lines.

-r       Reverse. Copies lines from the  specified  starting
point in the file in reverse order. The default for
r is to print the entire file in reverse order.

/usr/xpg4/bin/tail
The following options are supported  for  /usr/xpg4/bin/tail
only:

-c number       The number option-argument must be a decimal
integer  whose  sign affects the location in
the file, measured in bytes,  to  begin  the
copying:

+        Copying  starts  relative  to   the
beginning of the file.

–        Copying starts relative to the  end
of the file.

none     Copying starts relative to the  end
of the file.

The origin for counting is 1; that is,  -c+1
represents  the first byte of the file, -c-1
the last.

-n number       Equivalent to -cnumber, except the  starting
location  in  the  file is measured in lines
instead of bytes. The origin for counting is
1.  That  is, -n+1 represents the first line
of the file, -n-1 the last.

OPERANDS
The following operand is supported:

file     A path name of an input file. If no  file  operands
are specified, the standard input is used.

USAGE
See largefile(5) for the description of the behavior of tail
when encountering files greater than or equal to 2 Gbyte ( 2
**31 bytes).

EXAMPLES
Example 1: Using the tail Command

The following command prints 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.

example% tail -f fred

The next command prints 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:

example% tail -15cf fred

ENVIRONMENT VARIABLES
See environ(5) for descriptions of the following environment
variables  that  affect the execution of tail: LANG, LC_ALL,
LC_CTYPE, LC_MESSAGES, and NLSPATH.

EXIT STATUS
The following exit values are returned:

0        Successful completion.

>0       An error occurred.

ATTRIBUTES
See attributes(5) for descriptions of the  following  attri-
butes:

/usr/bin/tail
User Commands                                             tail(1)

____________________________________________________________
|       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
|_____________________________|_____________________________|
| Availability                | SUNWcsu                     |
|_____________________________|_____________________________|
| CSI                         | Enabled                     |
|_____________________________|_____________________________|

/usr/xpg4/bin/tail
____________________________________________________________
|       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
|_____________________________|_____________________________|
| Availability                | SUNWxcu4                    |
|_____________________________|_____________________________|
| CSI                         | Enabled                     |
|_____________________________|_____________________________|
| Interface Stability         | Standard                    |
|_____________________________|_____________________________|

SEE ALSO
cat(1),  head(1),  more(1),  pg(1),  dd(1M),  attributes(5),
environ(5), largefile(5), standards(5)

NOTES
Piped tails relative to the end of the file are stored in  a
buffer,  and  thus  are  limited in length. Various kinds of
anomalous behavior can happen with character special files.

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