NAME

tail − deliver the last part of a file

SYNOPSIS

tail [ ± number lbcr ] [ file ]
tail [ −lbcr ] [ file ]
tail [ ± number lbcf ] [ file ]
tail [ −lbcf ] [ file ]

DESCRIPTION

tail copies the named file to the standard output beginning at a designated place.  If no file is named, the standard input is used. 

Copying begins at distance +number from the beginning, or −number from the end of the input (if number is null, the value 10 is assumed).  Number is counted in units of lines, blocks, or characters, according to the appended option l, b, or c.  When no units are specified, counting is by lines. 

With the −f (follow) option, if the input file is not a pipe, the program will not terminate after the line of the input file has been copied, but will enter an endless loop, wherein it sleeps for a second and then attempts to read and copy further records from the input file.  Thus it may be used to monitor the growth of a file that is being written by some other process.  For example, the command:

tail −f fred

will print the last ten lines of the file fred, followed by any lines that are appended to fred between the time tail is initiated and killed.  As another example, the command:

tail −15cf fred

will print the last 15 characters of the file fred, followed by any lines that are appended to fred between the time tail is initiated and killed. 

The r option copies lines from the specified starting point in the file in reverse order.  The default for r is to print the entire file in reverse order. 

The r and f options are mutually exclusive. 

SEE ALSO

cat(1), head(1), more(1), pg(1), tail(1), dd(1). 

NOTES

Tails relative to the end of the file are stored in a buffer, and thus are limited in length.  Various kinds of anomalous behavior may happen with character special files. 

The tail command will only tail the last 4096 bytes of a file regardless of its line count. 

CX/UX User’s Reference Manual