Special shell variables
There are some variables which are set internally by the shell and which are available to the user:

Name Description
——————————————————————————–
$1 – $9 these variables are the positional parameters.

$0 the name of the command currently being executed.

$# the number of positional arguments given to this
invocation of the shell.

$? the exit status of the last command executed is
given as a decimal string. When a command
completes successfully, it returns the exit status
of 0 (zero), otherwise it returns a non-zero exit
status.

$$ the process number of this shell – useful for
including in filenames, to make them unique.

$! the process id of the last command run in
the background.

$- the current options supplied to this invocation
of the shell.

$* a string containing all the arguments to the
shell, starting at $1.

$@ same as above, except when quoted.

Branching
if then fi
if [[ $value -eq 7 ]];then
print "$value is 7"
fi
or:

if [[ $value -eq 7 ]]
then
print "$value is 7"
fior:

if [[ $value -eq 7 ]];then print "$value is 7";fi

if then else fi
if [[ $name = "John" ]];then
print "Your welcome, ${name}."
else
print "Good bye, ${name}!"
fi

if then elif then else fi
if [[ $name = "John" ]];then
print "Your welcome, ${name}."
elif [[ $name = "Hanna" ]];then
print "Hello, ${name}, who are you?"
else
print "Good bye, ${name}!"
fi

case esac
case $var in
john|fred) print $invitation;;
martin) print $declination;;
*) print "Wrong name...";;
esac

——————————————————————————–

Looping Command Syntax for Scripts

while do done
while [[ $count -gt 0 ]];do
print "\$count is $count"
(( count -= 1 ))
done
until do done
until [[ $answer = "yes" ]];do
print -n "Please enter \"yes\": "
read answer
print ""
done
for var in list do done
for foo in $(ls);do
if [[ -d $foo ]];then
print "$foo is a directory"
else
print "$foo is not a directory"
fi
done
continue…break
One can skip the rest of a loop and directly go to the next iteration with: “continue”.

while read line
do
if [[ $line = *.gz ]];then
continue
else
print $line
fi
done
One can also prematurely leave a loop with: “break”.

while read line;do
if [[ $line = *!(.c) ]];then
break
else
print $line
fi
done

http://www.well.ox.ac.uk/~johnb/comp/unix/ksh.html

Removing accounts from predefine list:

#!/bin/ksh

done

Or course, the sleep there is just for aesthetic.. I want to see the screen

getfacl is a file utility for viewing the access control list information associated with a file or directory.

For a memory aid, you can think of ‘getfacl’ as “Get File ACL“.. ACL being Access Control List.

Access control lists are extended attributes added to most major file systems in the 2.6 kernel to improve ability to control the access of files. They allow permissions to be set for individual groups and users and not just the owning user, owning group, and all other users.

setfacl is a command that allows you to set the Access Control List information for a file or directory.

Access control lists are extended attributes added to most major file systems in the 2.6 kernel to improve ability to control the access of files. They allow permissions to be set for individual groups and users and not just the owning user, owning group, and all other users.

You can read man pages for both getfacl and setfacl for more information.

getfacl and setfacl example….

Here’s an example of using the basic funtion of getfacl and setfacl

# getfacl

#setfacl

setfacl -m default:user::rwx,default:group::r-x,default:other:r-x,default:mask:rwx /u06/OneSource/datapump_dbdump

setfacl -m default:user:rcodapp1:r-x,default:group:r-x,default:other:—,default:mas:rwx /u06/OneSouce/datapump_dbdump

I check grep’d my account the walah! It was there! I reset the password, open an ssh terminal and tried to login. unsuccessful, that’s why i knew then that it is locked.

Here’s how to unlock a locked user account in HP UX in command line.

In HP-UX 11.xx if user account is locked, you can unlock the account by running SAM. But running SAM takes some time usually 2-3 minutes on heavily loaded HP-UX servers. You can unlock the locked user account from command line by running following command:

1. Login as root or use sudo from your account, if there is no sudo installed just use su – root :

$sudo su – *******

2. Run this command to unlock the locked HP-UX user account:

#/usr/lbin/modprpw –l –k johnm

Running modprpw will unlock the locked user account in HP-UX from command line.without running SAM

NOTE: modprpw is HP-UX command only and wouldn’t work in Solaris,AIX and any Linux servers

That info was ‘borrowed’ from here…. thanks!

“->” = ILOM
“sc>” = ALOM

.. and since this particular server has the “->” prompt we’re using the ILOM.

From ILOM to Solaris:
-> start /SP/console

From ALOM to Solaris:
sc> console

And of course.. Enter “#.” to return to ALOM / ILOM !!

Send Break on ILOM

set /HOST send_break_action=break
and then
start /SP/console

c)ontinue, s)ync, r)eset? s

bada bing! bada boom!

Apache is the most well known open source web server there is! Open source?? Make that the most wildly used webserver on the internet, period!

It is believed (and i know they made a survey or study about it) that Apache takes 90% of all web servers in the internet. Most web hosting company, and I’ve once worked in one, use Apache.

This post will talk about how to setup Apache for Virtual Hosting

Setting Up A Virtual Host in Apache

create a completely seperate document root, cgi-bin directory, and logfile directory for each host. You can place these beneath the standard Debian prefix of /var/www or you may use a completely different root

root@irony:~# mkdir /home/www

root@irony:~# mkdir /home/www/www.example.com
root@irony:~# mkdir /home/www/www.example.com/htdocs
root@irony:~# mkdir /home/www/www.example.com/cgi-bin
root@irony:~# mkdir /home/www/www.example.com/logs

root@irony:~# mkdir /home/www/www.example.net
root@irony:~# mkdir /home/www/www.example.net/htdocs
root@irony:~# mkdir /home/www/www.example.net/logs
root@irony:~# mkdir /home/www/www.example.net/cgi-bin

root@irony:~# mkdir /home/www/www.example.org
root@irony:~# mkdir /home/www/www.example.org/htdocs
root@irony:~# mkdir /home/www/www.example.org/logs

root@irony:~# mkdir /home/www/www.example.org/cgi-bin

NEt
Here we’ve setup three different directory trees, one for each site. If you wanted to have identical content it might make sense to only create one, and then use symbolic links instead.

The next thing to do is to enable virtual hosts in your Apache configuration. The simplest way to do this is to create a file called /etc/apache2/conf.d/virtual.conf and include the following content in it:

#
#  We're running multiple virtual hosts.
#
Nameserver *

NameVirtualHost *

(When Apache starts up it reads the contents of all files included in /etc/apache2/conf.d, and files you create here won’t get trashed on package upgrades.)

Once we’ve done this we can create the individual host configuration files. The Apache2 setup you’ll find on Debian GNU/Linux includes two directories for locating your site configuration files:

/etc/apache2/sites-available

This contains configuration files for sites which are available but not necessarily enabled.
/etc/apache2/sites-enabled

This directory contains site files which are enabled.

As with the conf.d directory each configuration file in the sites-enabled directory is loaded when the server starts – whilst the files in sites-available are completely ignored.

You are expected to create your host configuration files in /etc/apache2/sites-available, then create a symbolic link to those files in the sites-enabled directory – this will cause them to be actually loaded/read.

Rather than actually messing around with symbolic links the Debian package includes two utility commands a2ensite and a2dissite which will do the necessary work for you as we will demonstrate shortly.

Lets start with a real example. Create /etc/apache2/sites-available/www.example.com with the following contents:

#
#  Example.com (/etc/apache2/sites-available/www.example.com)
#
<VirtualHost *>
ServerAdmin webmaster@example.com
ServerName  www.example.com
ServerAlias example.com

# Indexes + Directory Root.
DirectoryIndex index.html
DocumentRoot /home/www/www.example.com/htdocs/

# CGI Directory
ScriptAlias /cgi-bin/ /home/www/www.example.com/cgi-bin/
<Location /cgi-bin>
Options +ExecCGI
</Location>

# Logfiles
ErrorLog  /home/www/www.example.com/logs/error.log
CustomLog /home/www/www.example.com/logs/access.log combined

</VirtualHost>

ow we’ve got:

• Three directories which can be used to contain our content.
• Three directories which can be used to contain our logfiles.
• Three directories which can be used to contain our dynamic CGI scripts.
• Three configuration files which are being ignored by Apache.

To enable the sites simply run:

root@irony:~# a2ensite www.example.com
Site www.example.com installed; run /etc/init.d/apache2 reload to enable.

root@irony:~# a2ensite www.example.net
Site www.example.net installed; run /etc/init.d/apache2 reload to enable.

root@irony:~# a2ensite www.example.org
Site www.example.org installed; run /etc/init.d/apache2 reload to enable.

This will now create the symbolic links so that /etc/apache2/sites-enabled/www.example.org, etc, now exist and will be read.

Once we’ve finished our setup we can restart, or reload, the webserver as the output above instructed us to do with:

root@irony:~# /etc/init.d/apache2 reload
Reloading web server config...done.
root@irony:~#

Anyway, you’re probably Googling about Arlo Gilbert as you read this post. Well, let me save you a few minutes and introduce you to Mr. Gilbert in one fast minute.

He is the following:

• The Man is from Austin, Texas
• Arlo Gilbert is a high school drop out… and a proud one (don’t do that boys and girls)
• A family man! So there’s a Mrs. Gilbert and two little Arlo Gilberts (daughters)

The reason why we feature this brilliant man is that he has successfully launched online startups and been doing it for 10 years now. Remember, high school dropout and no training in marketing or any business related studies… Brilliant indeed.

What caught my attention while reading his ‘About’ page was his current project – the iCall. It’s a VOIP startup company. I was wondering if iCall was developed by Arlo Gilbert or if it uses Asterisk?

.

.

.

Tekken Philippines

vi is the one, if not the most popular text editor available for a System Administrator on a UNIX and UNIX-like machines.

It has two modes, command and editor mode.

Here are some syntax in using the Search and Replace in ‘vi’.

Search:

The most basic and most easily remembered command for searching is vi is slash or ‘/’ followed by the character being searched. That’s for forward searching. For backward, vi use ‘?’ followed by the string being searched.

To go to the next occurrance of the string being searched, vi use ‘n’ command. Doesn’t matter if your searching forward (from up, down) or backward, from down to top.

Example:

(you have to be in command mode… press ESC first)

/search_string

?search_string

Search and Replace

For search and replace, use the syntax

:%s/original/replaced/g

Make sense?
Any command that begins with a “:” is called a line mode command and performs its duty on the line the cursor is currently on.

The above syntax serves my purpose now… If I want to replace text in certain ranges.. syntax can be found here

If / is full, run a command similar to the following to sort all files in the / file system by size:

find / -xdev -ls | sort -n -k 7

“-xdev” limits the find command to the root file system.

This will only look for files found in the root and will not includes those partitions that are defined in /etc/vfstab | /etc/fstab file, those listed when `df -k` is executed:

/dev/md/dsk/d0 2058319 1016097 980473 51% /
/dev/md/dsk/d3 2058319 1801793 194777 91% /var
etc .. etc..

Thanks Brandon!

Brandon H. – Senior UNIX Systems Engineer for an application services provider in Minneapolis, MN.

Network File System

NFS is Sun’s Networked File System, and by now, more or less, the de facto method of sharing file systems between computers.

Domain Name Service

DNS is the Domain Name Service, which is the way information about hostnames and addresses are shared across the Intenet.

Network Information (Name) Service

NIS stands for Network Information Name Service. It was original called Yellow Pages, which is why many of the commands for NIS start with yp (such as ypbind, ypcat, etc.) NIS was developed by Sun, and is, like NFS, more or less the default way of sharing system information between UNIX machines.

NIS+

NIS+ is Sun’s re-implementation of NIS. It attempts to address some of the problems with NIS, but the implementers of NIS+ have made a series of bad choices in the design of NIS+, so it has seen only limited usage compared to the other types of services you asked about.

Here’s a typical output of a file listing using `ls -l` on a directory:

[root@unix-box icons]# ls -l | more
total 636
-rw-r–r–    1 elizar root          246 Aug 26  2005 a.gif
-rw-r–r–    1 elizar root          242 Aug 26  2005 alert.black.gif
-rw-r–r–    1 elizar root          279 Aug 26  2005 alert.black.png
-rw-r–r–    1 elizar root          247 Aug 26  2005 alert.red.gif
-rw-r–r–    1 elizar root          298 Aug 26  2005 alert.red.png
-rw-r–r–    1 elizar root         2326 Aug 26  2005 apache_pb.gif
-rw-r–r–    1 elizar root         1385 Aug 26  2005 apache_pb.png
-rw-r–r–    1 elizar root          293 Aug 26  2005 a.png

When using the -l (dash ‘el’) option of ls, the output will display a more detailed listing of the files. Here you’ll see the file properties/permission (-rw-r–r–) the number of links, the owner of the file, the group of the user, file size, the date/time stamp and finally the file name. That’s 7 column.

Changing The Time Stamp Of A File

To change the time stamp of a file (the 6th column in the `ls -l` listing), we use the UNIX command touch.

From the Man Pag:

NAME
touch – change file timestamps

SYNOPSIS
touch [OPTION]… FILE…
touch [-acm] MMDDhhmm[YY] FILE… (obsolescent)

There are many options for the touch command, but the one I use fairly often is the -t option

       -t STAMP;    use [[CC]YY]MMDDhhmm[.ss]

Example:

 [root@unix-box icons]#  touch -t 200607161201 a.gif
[root@unix-box icons]# ls -l | more
total 636
-rw-r–r–    1 elizar root          246 Jul 16  2006 a.gif
-rw-r–r–    1 elizar root          242 Aug 26  2005 alert.black.gif

Other options that you  may find useful are -a (change access time only) -m (modification time only) and others. Consult the man page for more details

Cheers!