Mac Developer Library Developer
Search

 

This manual page is for Mac OS X version 10.9

If you are running a different version of Mac OS X, view the documentation locally:

  • In Terminal, using the man(1) command

Reading manual pages

Manual pages are intended as a quick reference for people who already understand a technology.

  • To learn how the manual is organized or to learn about command syntax, read the manual page for manpages(5).

  • For more information about this technology, look for other documentation in the Apple Developer Library.

  • For general information about writing shell scripts, read Shell Scripting Primer.




TAIL(1)                   BSD General Commands Manual                  TAIL(1)

NAME
     tail -- display the last part of a file

SYNOPSIS
     tail [-F | -f | -r] [-q] [-b number | -c number | -n number] [file ...]

DESCRIPTION
     The tail utility displays the contents of file or, by default, its standard input, to the standard out-put. output.
     put.

     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, ``-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, ``-n 2'' displays the last two lines of the input.  The
     default starting location is ``-n 10'', or the last 10 lines of the input.

     The options are as follows:

     -b number
             The location is number 512-byte blocks.

     -c number
             The location is number bytes.

     -f      The -f option causes tail to not stop when end of file is reached, but rather to wait for addi-tional additional
             tional data to be appended to the input.  The -f option is ignored if the standard input is a
             pipe, but not if it is a FIFO.

     -F      The -F option implies the -f option, but tail will also check to see if the file being followed
             has been renamed or rotated.  The file is closed and reopened when tail detects that the file-name filename
             name being read from has a new inode number.  The -F option is ignored if reading from standard
             input rather than a file.

     -n number
             The location is number lines.

     -q      Suppresses printing of headers when multiple files are being examined.

     -r      The -r option causes the input to be displayed in reverse order, by line.  Additionally, this
             option changes the meaning of the -b, -c and -n options.  When the -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 -r option is to display all of the input.

     If more than a single file is specified, each file is preceded by a header consisting of the string
     ``==> XXX <=='' where XXX is the name of the file unless -q flag is specified.

EXIT STATUS
     The tail utility exits 0 on success, and >0 if an error occurs.

SEE ALSO
     cat(1), head(1), sed(1)

STANDARDS
     The tail utility is expected to be a superset of the IEEE Std 1003.2-1992 (``POSIX.2'') specification.
     In particular, the -F, -b and -r options are extensions to that standard.

     The historic command line syntax of tail is supported by this implementation.  The only difference
     between this implementation and historic versions of tail, once the command line syntax translation has
     been done, is that the -b, -c and -n options modify the -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 -c option and display the last 4 lines of the input.

HISTORY
     A tail command appeared in PWB UNIX.

BSD                              June 29, 2006                             BSD

Reporting Problems

The way to report a problem with this manual page depends on the type of problem:

Content errors
Report errors in the content of this documentation with the feedback links below.
Bug reports
Report bugs in the functionality of the described tool or API through Bug Reporter.
Formatting problems
Report formatting mistakes in the online version of these pages with the feedback links below.

Feedback