tail - output the last part of files
tail [-c [+]N[bkm]] [-n [+]N] [-fqv] [--bytes=[+]N[bkm]] [--lines=[+]N] [--follow] [--quiet] [--silent] [--verbose] [--help] [--version] [file...] tail [{-,+}Nbcfklmqv] [file...]
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, option- ally followed by one of the following characters to specify a different unit. b 512-byte blocks. k 1-kilobyte blocks. m 1-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 when- -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 status code indicating success. --version Print version information on standard output then exit.