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

NAME

ttaaiill - display the last part of a file

SYNOPSIS

ttaaiill [-FF | -ff | -rr] [-bb number | -cc number | -nn number] [file ...]

DESCRIPTION

The ttaaiill utility displays the contents of file or, by default, its stan-

dard input, to the standard output.

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 loca-

tion is ``-n 10'', or the last 10 lines of the input.

The options are as follows:

-bb number

The location is number 512-byte blocks.

-cc number

The location is number bytes.

-ff The -ff option causes ttaaiill to not stop when end of file is

reached, but rather to wait for additional data to be appended to

the input. The -ff option is ignored if the standard input is a

pipe, but not if it is a FIFO.

-FF The -FF option implies the -ff option, but ttaaiill will also check to

see if the file being followed has been renamed or rotated. The file is closed and reopened when ttaaiill detects that the filename

being read from has a new inode number. The -FF option is ignored

if reading from standard input rather than a file.

-nn number

The location is number lines.

-rr The -rr option causes the input to be displayed in reverse order,

by line. Additionally, this option changes the meaning of the

-bb, -cc and -nn options. When the -rr 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 -rr 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. DIAGNOSTICS The ttaaiill utility exits 0 on success, and >0 if an error occurs.

SEE ALSO

cat(1), head(1), sed(1) STANDARDS

The ttaaiill utility is expected to be a superset of the IEEE Std 1003.2-1992

(``POSIX.2'') specification. In particular, the -FF, -bb and -rr options

are extensions to that standard.

The historic command line syntax of ttaaiill is supported by this implementa-

tion. The only difference between this implementation and historic ver-

sions of ttaaiill, once the command line syntax translation has been done, is

that the -bb, -cc and -nn options modify the -rr 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 -cc

option and display the last 4 lines of the input. HISTORY A ttaaiill command appeared in PWB UNIX. BSD June 6, 1993 BSD




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