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.
arguments to long options are mandatory for short options
output the last NUM bytes; or use −c +NUM to output starting with byte NUM of each file
output appended data as the file grows;
an absent option argument means ’descriptor’
same as −−follow=name −−retry
output the last NUM lines, instead of the last 10; or use −n +NUM to output starting with line NUM
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 inotify, this option is rarely useful
with −f, terminate after process ID, PID dies
−q, −−quiet, −−silent
never output headers giving file names
keep trying to open a file if it is inaccessible
with −f, sleep for approximately N seconds (default 1.0) between iterations; with inotify and −−pid=P, check process P at least once every N seconds
always output headers giving file names
line delimiter is NUL, not newline
display this help and exit
output version information and exit
NUM may have a multiplier suffix: b 512, kB 1000, K 1024, MB 1000*1000, M 1024*1024, GB 1000*1000*1000, G 1024*1024*1024, and so on for T, P, E, Z, Y.
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 in a way that accommodates renaming, removal and creation.
Written by Paul Rubin, David MacKenzie, Ian Lance Taylor, and Jim Meyering.
© 2018 Free Software Foundation, Inc. License GPLv3+:
GNU GPL version 3 or later
This is free software: you are free to change and redistribute it. There is NO WARRANTY, to the extent permitted by law.
or available locally via: info '(coreutils) tail invocation'