tail - output the last part of files
tail [OPTION]... [FILE]...
Print the last 10 lines of each FILE to standard output. With more than one FILE, precede each with a header giving the file name. With no FILE, or when FILE is -, read standard input.
Mandatory arguments to long options are mandatory for short options too.
keep trying to open a file even if it is inaccessible when tail starts or if it becomes inaccessible later -- useful only with -f
output the last N bytes
output appended data as the file grows; -f, --follow, and --follow=descriptor are equivalent
same as --follow=name --retry
output the last N lines, instead of the last 10
with --follow=name, reopen a FILE which has not changed size after N (default 5) iterations to see if it has been unlinked or renamed (this is the usual case of rotated log files)
with -f, terminate after process ID, PID dies
-q, --quiet, --silent
never output headers giving file names
with -f, sleep for approximately S seconds (default 1.0) between iterations.
always output headers giving file names
display this help and exit
output version information and exit
If the first character of N (the number of bytes or lines) is a `+', print beginning with the Nth item from the start of each file, otherwise, print the last N items in the file. N may have a multiplier suffix: b 512, k 1024, m 1024*1024.
With --follow (-f), tail defaults to following the file descriptor, which means that even if a tail'ed file is renamed, tail will continue to track its end. This default behavior is not desirable when you really want to track the actual name of the file, not the file descriptor (e.g., log rotation). Use --follow=name in that case. That causes tail to track the named file by reopening it periodically to see if it has been removed and recreated by some other program.