NAME

tail − output the last part of files

SYNOPSIS

tail [−c [+]N[bkm]] [−n [+]N] [−fqv] [−−bytes=[+]N[bkm]] [−−lines=[+]N] [−−follow] [−−quiet] [−−silent] [−−verbose] [−−help] [−−version] [file...]
 
tail [{−,+}Nbcfklmqv] [file...]

DESCRIPTION

This manual page documents the GNU version of tail.  tail prints the last part (10 lines by default) of each given file; it reads from standard input if no files are given or when a filename of ‘−’ is encountered.  If more than one file is given, it prints a header consisting of the file’s name enclosed in ‘==>’ and ‘<==’ before the output for each file. 

The GNU tail can output any amount of data, unlike the Unix version, which uses a fixed size buffer.  It has no −r option (print in reverse).  Reversing a file is really a different job from printing the end of a file; the BSD tail can only reverse files that are at most as large as its buffer, which is typically 32k.  A reliable and more versatile way to reverse files is the GNU tac command. 

OPTIONS

tail accepts two option formats: the new one, in which numbers are arguments to the option letters, and the old one, in which a ‘+’ or ‘−’ and optional number precede any option letters. 

If a number (‘N’) starts with a ‘+’, tail begins printing with the Nth item from the start of each file, instead of from the end. 

−c N, −−bytes N
Tail by N bytes.  N is a nonzero integer, optionally followed by one of the following characters to specify a different unit.

b512-byte blocks. 

k1-kilobyte blocks. 

m1-megabyte blocks. 

−f, −−follow
Loop forever trying to read more characters at the end of the file, on the assumption that the file is growing.  Ignored if reading from a pipe.  If more than one file is given, tail prints a header whenever it gets output from a different file, to indicate which file that output is from. 

−l, −n N, −−lines N
Tail by N lines. −l is only recognized using the old option format. 

−q, −−quiet, −−silent
Never print filename headers.

−v, −−verbose
Always print filename headers.

−−help
Print a usage message and exit with a non-zero status.

−−version
Print version information on standard output then exit.