tail --help

Usage: tail [OPTION]... [FILE]...

Print the last  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=K            output the last K bytes; or use -c +K to output

                             bytes starting with the Kth 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=K            output the last K lines, instead of the last ;

                             or use -n +K to output starting with the Kth

      --max-unchanged-stats=N

                           with --follow=name, reopen a FILE which has not

                             changed size after N (default ) 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

      --help     display this help and exit

      --version  output version information and exit

If the first character of K (the number of bytes or lines) is a '+',

print beginning with the Kth item from the start of each file, otherwise,

print the last K items in the file.  K may have a multiplier suffix:

b , kB , K , MB *, M *,

GB **, G **, 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.

[centos@s203 ~]$ head -n  test.sh

No Name Mark Percent

tom

jack

alex

[centos@s203 ~]$ head -n  test.sh

No Name Mark Percent

tom

[centos@s203 ~]$ head -n  -v test.sh

==> test.sh <==

No Name Mark Percent

tom

[centos@s203 ~]$ head -n  -v -q test.sh

No Name Mark Percent

tom

[centos@s203 ~]$ head -n  -v -q -c  test.sh

No [centos@s203 ~]$

[centos@s203 ~]$

[centos@s203 ~]$

[centos@s203 ~]$ head  -v -q -c  test.sh

No [centos@s203 ~]$ head -n  -v -q -c  test.sh

No Name Mark Percent

tom

jack

alex

[centos@s203 ~]$ head -n  -v -q -c  test.sh

No Name Ma[centos@s203 ~]$