Symas OpenLDAP Knowledge Base

OS Modifications and Facts

Run Windows in a VM in Ubuntu

    http://www.howtogeek.com/howto/18768/run-windows-in-ubuntu-with-vmware-player/ 
    http://serverfault.com/questions/416003/linux-different-size-for-df-and-du-for-root-partition 

Determine Linux Version

    cat /proc/version  

System Properties/Details

    uname -a 

Program Path Variables

    echo $PATH 

To modify $PATH for an individual user “cd /home/

    VIM .bashrc 

At the bottom of the file add path (see example below)

    PATH=""/opt/symas/bin:/opt/symas/lib64:$PATH"" 
    VIM .profile 

You will need to source your .bashrc or .profile files, or logout/login (or restart the terminal) for the changes to take effect. To source your .bashrc or .profile files, simply type

    source .bashrc   (when in the home directory) 
    source .profile  (when in the home directory)" 

To Modify $PATH for all users

Create the file /etc/profile.d/myenvvars.sh (all .sh files in /etc/profile.d are run on log-on)

    touch /etc/profile.d/myenvvars.sh 

and set variables like this

    VIM myenvvars.sh 
    export PATH=$PATH:/opt/symas/bin:/opt/symas/lib64 

Connect to VPN

    ssh jtrupp@crwth.ext.symas.net (after @ replace with any servername) 

Enter password for remote network”

View Connected Users

    In Terminal prompt type "W" (without the quotes) and press Enter 

Application Install/Uninstall

    apt-get install {package}  

Install the new package. If package is installed then try to upgrade to latest version.

Example:

    apt-get install zip 
    apt-get install lsof samba mysql-client" 
    dpkg -i {package} 

Installs downloaded package

Example:

    dpkg -i package.deb 
    apt-get remove {package} 

Remove/Delete an installed package except configuration files

Example:

    apt-get remove zip 
    dpkg -r {package} 

Uninstalls package except configuration files

Example:

    dpkg -r package.deb 
    apt-get --purge remove {package} 

Remove/Delete everything including configuration files

Example:

    apt-get --purge remove mysql-server 
    dpkg --purge {package} 

Uninstalls package and all related files

Example:

    dpkg --purge package.deb 
    apt-get update  

Resynchronize the package index files and Upgrade the Debian Linux system including security update (Internet access required). Usually used to upgrade to Debian distribution. For example Woody to Sarge upgrade.

    apt-get dist-upgrade 

In addition to performing the function of upgrade, ‘dist-upgrade’ also intelligently handles changing dependencies with new versions of packages; apt-get has a “smart” conflict resolution system, and it will attempt to upgrade the most important packages at the expense of less important ones if necessary.

TASKKILL Process

ps ax | grep -i [programname] Example: ps ax | grep -i wine

pgrep taskname Example: pgrep slapd You’re looking for the first column of the returned value, say 2483 (this is the process ID/PID).

Now type
kill -term 2483 It will send SIGTERM to wine, which (assuming it can receive any signals) will cause Wine to terminate gracefully.

If not, you can type kill -9 2483

It will try to terminate Wine with prejudice, without giving it a chance to save its data files.

If not, you can type kill

If this /still/ doesn’t work, as a last resort you can try sudo kill -9 2483

It will ask you for your password. Now it’ll kill Wine from a higher privilege level, which it should be unable to ignore. (Invincible!)”

ECHO %COMPUTERNAME% or %LOGONSERVER% Euivalent

    hostname - show or set the system’s host name 
    dnsdomainname - show the system’s DNS domain name 

SYNOPSIS

    hostname  [-v] [-a] [--alias] [-d] [--domain] [-f] [--fqdn] [-i] [--ip- 
    address] [--long] [-s] [--short] [-y] [--yp] [--nis] 
    hostname [-v] [-F filename] [--file filename] [hostname] 
    hostname [-v] [-h] [--help] [-V] [--version] 
    dnsdomainname [-v] 

DESCRIPTION

Hostname is used to either set or display the current host or domain name of the system. This name is used by many of the networking programs to identify the machine. The domain name is also used by NIS/YP.

GET NAME

When called without any arguments, the program displays the current names:

    hostname will  print  the  name  of  the  system  as  returned  by  the gethostname(2) 
      function. 
    dnsdomainname  will  print the domain part of the FQDN (Fully Qualified Domain Name). 
      The complete FQDN of the system is returned with hostname --fqdn. 

SET NAME

When called with one argument or with the –file option, the commands set the host name or the NIS/YP domain name. Note that this is effective only until the next reboot.

    Edit /etc/hostname for permanent change. 

Note, that only the super-user can change the names. It is not possible to set the FQDN or the DNS domain name with the dnsdomainname command (see THE FQDN below). The host name is usually set once at system startup in /etc/rc.d/rc.inet1 or /etc/init.d/boot (normally by reading the contents of a file which contains the host name, e.g. /etc/hostname).

THE FQDN

You can’t change the FQDN (as returned by hostname –fqdn) or the DNS domain name (as returned by dnsdomainname) with this command. The FQDN of the system is the name that the resolver(3) returns for the host name. Technically: The FQDN is the name gethostbyname(2) returns for the host name returned by gethostname(2). The DNS domain name is the part after the first dot. Therefore it depends on the configuration (usually in /etc/host.conf) how you can change it. Usually (if the hosts file is parsed before DNS or NIS) you can change it in /etc/hosts.

OPTIONS

    -a, --alias  Display the alias name of the host (if used). 
    -d, --domain  Display  the  name  of  the  DNS  domain.  Don’t use the command domainname 
                  to get the DNS domain name because it will  show the NIS  domain  name and 
                  not the DNS domain name. Use dnsdomainname instead. 
    -F, --file filename  Read the host name from  the  specified  file.  
                         Comments  (lines starting with a ‘#’) are ignored. 
    -f, --fqdn, --long  Display  the FQDN (Fully Qualified Domain Name). A FQDN consists of a 
                        short host name and the DNS domain  name.  Unless you are using  bind                             or NIS for host lookups you can change the FQDN and the DNS  domain  
                        name  (which  is  part  of  the  FQDN)  in  the /etc/hosts file. 
    -h, --help  Print a usage message and exit. 
    -i, --ip-address  Display the network address(es) of the host. 
    -s, --short  Display  the  short  host name. This is the host name cut at the first dot. 
    -V, --version  Print  version  information  on   standard   output   and   exit 
                   successfully. 
    -v, --verbose  Be verbose and tell what’s going on. 
    -y, --yp, --nis  Display  the NIS domain name. If a parameter is given (or --file name ) 
                     then root can also set a new NIS domain. 

NOTES

    The address families hostname tries when looking up the  FQDN,  aliases and  network  
    addresses of the host are determined by the configuration of your resolver. 
    
    For instance, on GNU Libc systems, the resolver can be  instructed  to  try IPv6 lookups 
    first by using the inet6 option in /etc/resolv.conf. 
    

FILES

    /etc/hosts /etc/hostname This file should only contain domain name  and not the full FQDN

View a History of Entered Commands

    history | grep <searchword> 
      !Command# (will rerun command) 
      CTRL+r first few letters of previous command (will auto-populate w/command from history 
      CTRL+r Vl   (will load previous Vl text editor commands)" 

Setup System Monitor

    wget http://tecmint.com/wp-content/scripts/tecmint_monitor.sh 
    chmod 755 tecmint_monitor.sh 
    ./tecmint_monitor.sh -i 
    Enter root password when prompted 

Run the script by executing the following in a terminal

    monitor 

To see what version is installed execute the following

    monitor -v