Tail (Bash)

tail prints the last couple of lines of a file (by default the last 10) - handy for e.g., log files

$ man tail

TAIL(1)                                            User Commands                                            TAIL(1)

NAME
       tail - output the last part of files

SYNOPSIS
       tail [OPTION]... [FILE]...

DESCRIPTION
       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.

       -c, --bytes=[+]NUM
              output the last NUM bytes; or use -c +NUM to output starting with byte NUM of each file

       -f, --follow[={name|descriptor}]
              output appended data as the file grows;

              an absent option argument means 'descriptor'

       -F     same as --follow=name --retry

       -n, --lines=[+]NUM
              output the last NUM lines, instead of the last 10; or use -n +NUM to output starting with line NUM

       --max-unchanged-stats=N
              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

       --pid=PID
              with -f, terminate after process ID, PID dies

       -q, --quiet, --silent
              never output headers giving file names

       --retry
              keep trying to open a file if it is inaccessible

       -s, --sleep-interval=N
              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

       -v, --verbose
              always output headers giving file names

       -z, --zero-terminated
              line delimiter is NUL, not newline

       --help display this help and exit

       --version
              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.

AUTHOR
       Written by Paul Rubin, David MacKenzie, Ian Lance Taylor, and Jim Meyering.

REPORTING BUGS
       GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
       Report tail translation bugs to <https://translationproject.org/team/>

COPYRIGHT
       Copyright   ©   2018   Free  Software  Foundation,  Inc.   License  GPLv3+:  GNU  GPL  version  3  or  later
       <https://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent per‐
       mitted by law.

SEE ALSO
       head(1)

       Full documentation at: <https://www.gnu.org/software/coreutils/tail>
       or available locally via: info '(coreutils) tail invocation'

GNU coreutils 8.30                                 September 2019                                           TAIL(1)

Examples

sudo tail /var/log/apache/error.log -n25

See also

• PHP-log

Sources

• http://ss64.com/bash/tail.html