tail(1) - Linux man page

Name

Synopsis

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.

--retry

keep trying to open a file even if it is inaccessible when tail starts or if it becomes inaccessible later; useful when following by name, i.e., with
--follow=name

-c, --bytes=N

output the last N bytes

-f, --follow[={name|descriptor}]

output appended data as the file grows; -f, --follow, and --follow=descriptor are equivalent

-F

same as --follow=name --retry

-n, --lines=N

output the last N lines, instead of the last 10

--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)

--pid=PID

with -f, terminate after process ID, PID dies

-q, --quiet, --silent

never output headers giving file names

-s, --sleep-interval=S

with -f, sleep for approximately S seconds (default 1.0) between iterations.

-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 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.

Adopt 10 good habits




Ten good habits to adopt are:





1. Make directory trees in a single swipe.


2. Change the path; do not move the archive.


3. Combine your commands with control operators.


4. Quote variables with caution.


5. Use escape sequences to manage long input.


6. Group your commands together in a list.


7. Use xargs outside of find.


8. Know when grep should do the counting -- and when it
   should step aside.


9. Match certain fields in output, not just lines.


10. Stop piping cats.

The 10 additional good habits you should adopt are:





• Use file name completion.


• Use history expansion.


• Reuse previous arguments.


• Manage directory navigation with pushd
  and popd.
  


• Find large files.


• Create temporary files without an editor.


• Use the curl command-line utility.


• Make the most of regular expressions.


• Determine the current user.


• Process data with awk.

Adding New Users to MySQL

by Jeff Hunter, Sr. Database Administrator

You can add new users to MySQL in two different ways: by using the GRANT
statement or my manipulating the MySQL grant tables directly. The preferred method
is to use the GRANT statement because they are more concise and less error-prone.

The following examples show how to use the mysql client to set up new users.
These examples assume that privileges are set up according to the defaults provided
in the previous MySQL DBA Tip, "Setting Up the Initial MySQL Privileges". This means
that to make changes, you must be on the same machine where mysqld is running,
you must connect as teh MySQL root user, and the root user must have
the insert privilege for the mysql database and the reload
administrative privilege. Also, if you have changed the root user password,
you must specify it for the following mysql commands:

You can add new users by issuing GRANT statements:

  % mysql -u root mysql
  mysql> GRANT ALL PRIVILEGES ON *.* TO oracle@localhost
      -> IDENTIFIED BY 'manager' WITH GRANT OPTION;

  mysql> GRANT ALL PRIVILEGES ON *.* TO oracle@"%"
      -> IDENTIFIED BY 'manager' WITH GRANT OPTION;

  mysql> GRANT RELOAD, PROCESS ON *.* TO admin@localhost;

  mysql> GRANT USAGE ON *.* TO dummy@localhost;

The GRANT statements (above) create and set up three new users:

Here are other command history shortcuts which may come in handy for
you:


• "Bang, bang": Typing !! (called "bang bang")
  executes the last command in the history.
  

• "Bang number": Typing
  !number (as in
  !302) will execute the command which is
  numbered 302 in the history file.
  

• "Bang string": Typing
  !string (as in
  !rpm) will execute a command with that
  matching string from the history file.
  

• Up arrow and down-arrow: At
  the Bash shell prompt, you can simply press the Up
  arrow to move back through previous commands in your
  history list (the Down arrow will move you
  forward through the commands) until you find the command you
  want. Press Enter to execute the command, just
  as if you had typed it on the command line.
  

3. ``Putting'' an entire directory

ucsu>  scp -r  research  newton:MyRsrch/09/

copy directory ``research'' recursively (i.e., the directory
and all its contents) from ucsu
into a new directory
``MyRsrch/09/'' in your home directory on newton

(the directory ``MyRsrch'' must already exist).

Sometimes a better alternative is to create a
tar file, then copy over

only that single tar file
and unpack it on the remote host.

4. ``Getting'' an entire directory

ucsu>  scp -r  smithj@euclid.ucla.edu:MyRsrch/09 ./r9/

copy directory ``MyRsrch/09/'' recursively (i.e., the directory
and all its contents) from
euclid.ucla.edu (where you are
"smithj" into a new directory ``r9/'' in your current
working directory on ucsu.

Sometimes a better alternative is to ssh to the remote
computer, bundle the
files you want into a single
tar file, scp that file over,
and unpack it where you want the files.

Linux / Unix, BSD 4.2+, and Apple OS X,
Operating System Users




For Linux or Unix users, to view their IP address or network
information, users must have administrator or root privileges. 





1. Open the Linux or Unix shell
   if you are utilizing a GUI interface for your Linux or Unix
   machine.


2. From the prompt, type
   "ifconfig eth0"
   (without the quotes) and press enter. This should give you a
   listing of network information similar to what is seen below.





eth0 	Link encap:Ethernet HWaddr 00:A0:24:72:EB:0A
  	inet addr:10.10.10.2 Bcast:10.0.0.255 Mask:255.255.255.0
  	UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
  	RX packets:5569799 errors:32 dropped:32 overruns:0 frame:6
  	TX packets:3548292 errors:0 dropped:0 overruns:0 carrier:3
  	Collisions:14
  	Interrupt:18 Base address:0xda00




As seen from the above example, users will commonly see the
network settings for all their network devices when running the
"ifconfig" command. First in the above example we have the
network settings for the "lo" or "local
loopback", next is the actual network settings of your network
adapter.




Home network and corporate network users




This information is the IP address of your computer
in your network. If you're computer is connected to the Internet the
IP address shown in this screen will more than likely not be
the IP address other people and web pages see. To determine this IP
address easily see the below online service section.