tail [ -fr ] [ -n nlines ] [ -c ncharacters ] [ file ]
Copying begins at position + number measured from the beginning, or - number from the end of the input. Number is counted in lines, 1K blocks or characters, according to the appended flag .LR l , .LR b , or .LR c . Default is -10l (ten ell).
The further flag .L r causes tail to print lines from the end of the file in reverse order; .L f (follow) causes tail, after printing to the end, to keep watch and print further data as it appears.
The second syntax is that promulgated by POSIX, where the numbers of lines (-n) or characters (-c) are specified separately as signed integers. Note than an unsigned value is treated as negative, ie '-n 2' is equivalent to '-n -2'.
tail file Print the last 10 lines of a file.
tail +0f file Print a file, and continue to watch data accumulate as it grows.
According to custom, option + number counts lines from 1, and counts blocks and characters from 0.
tail -nlines +3 file Print a file starting at line number 3