.TH TAIL 1 "2008-1.01" "pdcore utilities" "User Commands" .SH NAME tail \- copy the last part of a file .SH SYNOPSIS .B tail [-f] [-c number | -n number] [file] .SH DESCRIPTION Copy the input file to standard output, starting from a specified location. .SH OPTIONS .TP -f Follow the file; keep updating tail's output as the input file grows. Note that this option is only available for regular files and FIFOs that are named as the 'file' operand, and will be ignored for other inputs (such as unnamed pipes). .TP -c number Byte offset of the input file at which output will commence. .TP -n number Line offset of the input file at which output will commence. .P Byte and line offsets commence at the value 1. If 'number' includes a leading '+', the offset is from the start of the input file. If 'number' includes a leading '-' or has no prefix, it indicates that the desired offset is backwards from the end of the input file. .P For example, '-n +3' will output the contents of the input file commencing from the third line; '-c 20' or '-c -20' starts output twenty bytes prior to the end of the input file. .P For byte offsets, a 'number' value of zero is not permitted. For line offsets, the POSIX standard states that the option '-n 0' is valid, but outputs nothing, whilst '-n +0' is invalid. .P Options '-c' and '-n' are mutually exclusive. If neither is specified, the default behaviour of tail is to output the last ten lines of the input file, as if it had been invoked with the option '-n 10'. .SH OPERANDS .TP file Input file. If none provided, or the filename '-' is passed to tail, standard input will be used. .SH "AUTHORITATIVE DOCUMENTATION" .SH VERSION AND COMPLIANCE Utility version 1.01 .P Functional compliance with POSIX:2008 (IEEE Std 1003.1-2008; Shell and Utilities, Base Specifications Issue 7). .SH UNLICENSE This is free and unencumbered software released into the public domain, provided "as is", without warranty of any kind, express or implied. See the file UNLICENSE and the website for further details.