Regular Commands in UNIX

a)      To find out the running processes the command is                 :Ps – ef| grep java

b)       To find out the disk space the command is                           :du

c)      To find out the file system the command is                            :df

d)     To find out the network performance/port info command is   :netstat

e)      To find out the CPU utilisation the command is                     : topas/osstat

f)       To kill the running process the command is                           : kill -9 <PID>

g)      To generate heap/thresd dump the command is                    :kill -3 <PID>

h)      To  change the privileges of the file/folder the command is    : chmod

i)        To  change the owner of the file/folder the command is         :chown

j)        To  list the file the command is                                             : ls

k)      To create DIR(folder) the command is                                 :mkdir

l)        To TAR the files ,folders we use the following command

Tar –xvf  <file name with path>         --

Tar – uvf                                             --adding one or two files two folder

Tar – cvf                                              -- total folder

m)    To schedule the job in cron command is as follwos

Crontab –l ( to list all the scheduled jobs)

Crontab –e ( to edit the  scheduled job)

                        Whithin the crontab the syntax for the schedule the script as follows

Ex:  30 6  *  * 1,3,5  /usr/bin/calender

30(minutes)  6 (hours) *(day of the month)  * (month of the year) 1,3,5  (day no of the week)/usr/bin/calender

In the  above example we scheduled the script called calender which is located in the location “/usr/bin” to run every  Monday,Wednesday and friday

n)      To find fully qualified domain name (FQDN) if you know IP

$ Nslookup <IP_ADDRESS>                                    --(vice versa)