LINUX CLASSES - DATA MANIPULATION 
Heads or Tails?
 
The head command displays the first few lines at the top of a file. It can be useful when you want a quick peek at a large file, as an
alternative to opening the file with a text editor. By default, head will show the first ten lines of a file, but you can also tell it how
many lines to display. Here are a couple of examples:
 
head some.file	Show first ten lines of 
some.file.
 
head -5 some.file	Show first five lines of some.file.
 
The tail Command
 
The tail command displays the last few lines of a file. Like head, it can save you time, because it's a lot quicker than calling up a
file with a text editor and scrolling all the way down to the bottom. By default, tail will show the last ten lines of a file, but you can
also tell it how many lines to display:
 
tail some.file	Show last ten lines of s
ome.file.
tail -3 some.file	Show last three lines of some.file.
 
Here's a practical example of how to use the tail command. Many Linux programs put diagnostic messages in the
/var/syslog/messages file when they run, so this file can get pretty large after a while. To see if your most recent
command issued any messages, look at the tail end of this file by entering the tail /var/syslog/messages command.
 
For more information on the head command, see the
head manual.
 
For more information on the tail command, see the
tail manual.
 
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  Comments - most recent first(Please feel free to answer questions posted by others!)
  E     (08 Apr 2013, 17:49 )
   
  How would I get a shell script 
 $./ShellScriptName filename first-line last-line
 
 How would I make this work for example:
 ./ShellScriptName filename 5 10  - will output lines 5 through 10 of the
file. cheers!
 
  Sharyl03     (29 Oct 2012, 23:08 )
   
  Thanks in advance and good luck, lowfatlinux.com ! :) good luck
   
  Hassan     (14 Oct 2012, 00:21 )
   
  If you do an "ls" in /etc, what is the 100th filename from the END?
   
  Deena1960     (05 Sep 2012, 07:03 )
   
  I found this post earlier today while in the office Very useful Sent the
link to myself and will most likely bookmark lowfatlinux.com when I make it
home
   
  Claretha1999     (04 Sep 2012, 19:42 )
   
  Very informative post. Thanks lowfatlinux.com for taking the time to share
your view with us.
   
  satinder kaur     (18 Jan 2012, 00:49 )
   
  tail mostly used to check logs in log table
   
  Dave     (29 Nov 2011, 05:28 )
   
  Let's say that I have a .dat file with a few entries such as
CustomerID:LastName:FirstName:PhoneI am trying to use tail to grab the last line of the customerinfo.dat file
for the highest CustomerID and set a varible for that CustomerID number. 
Basically, I need to see if customerinfo.dat exists. If the file exists,
then search the file for the last customerID, add 1 to that number to start
creating a new customer.  If that customerinfo.dat file does not exist,
then it will set the CustomerID field to 1.  Any help?  I am a real newb to
this.
 
  gardenman     (07 Nov 2011, 08:41 )
   
  To show the 1st 50 lines just use head -50 <filename>.This is a great
site!
   
  janki     (05 Nov 2011, 01:03 )
   
  can we display the last 50 lines by using tail command???
   
  Pam     (20 Apr 2011, 11:51 )
   
  We just upgraded from OS 3 to OS 5.  Not sure if that is my problem or not.
 I have a script that displays the "head" of a file.  I get lots of extra
characters.  This is first line:  backupbanner.goodThis displays correctly using the more command.  Using head or cat it
displays backupbanner.good100666 000350 000001 00000001031 and a lot more
gobbly gook.
 Any suggestions?
 
  slamsnany     (27 Mar 2011, 18:46 )
   
  mine Sony Ericsson W700i..
   
  suraj     (26 Dec 2010, 03:11 )
   
  i want all the bash commands like head, tail etc....plz
 
  Kannah     (03 Dec 2010, 09:01 )
   
  I've been reading your tutorial for the past few hours.. Its all short and sweet.. Thanks buddy..
 
  Bob Rankin     (25 Aug 2010, 14:44 )
   
  @Abhilash - Thanks!  I'll be waiting for you to send your updates.  How
soon should I expect the "full info"?
   
  Abhilash     (25 Aug 2010, 01:40 )
   
  Thanq but u have not given full info about it
   
  raghu     (10 Aug 2010, 07:24 )
   
  how to print 1st 10 lines using telnet command
   
  deepak pandey     (03 May 2010, 20:52 )
   
  how many lines selected in head & tail command
   
  Sam     (26 Apr 2010, 22:12 )
   
  There could be a empty line at the end of the file
   
  Deepak Soni     (15 Apr 2010, 02:11 )
   
  When i using the tail command astail -1 "file_name". then it not show on the telnet screen. and using the
command as
 tail -2 "file_name". then it shows the last line of the file. why it not
show the last line with tail -1 "file_name". please reply.
 
  R.L.     (10 Apr 2010, 08:19 )
   
  Thanks a lot, this pages on Linux data manipulation helped me with my
university's exam project.
   
  Bob Rankin     (02 Apr 2010, 15:40 )
   
  Okay, let's play a mail game.  You send me $1000 through mail, and then
I'll guide you about command!
   
  Gagandeep Singh     (01 Apr 2010, 23:29 )
   
  Guide me about command through mail...
   
 I welcome your comments.  However... I am puzzled by many people 
who say "Please send me the Linux tutorial." This website *is* your Linux Tutorial!  Read everything here, learn 
all you can, ask questions if you like. But don't ask me to send what you already have.  :-) 
 NO SPAM!  If you post garbage, it will be deleted, and you will be banned.
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