RPM package contain the file and directories associated with specific application and program.
RPM namegenerally includes version, release and architecture for which it was build.
Like
Zip-2.3-8.i386.rpm
To install RPM:
#rpm –i rpm_name
To Remove RPM
#rpm –e rpm_name
In order to remove those package which has dependency
#rpm –e rpm_name –nodeps
Switches used with RPM
-i or --install
-e or --erase
-U or--Upgrade
-F or --Freshen
we can install rpm by using
#rpm –ivh rpm_name
-I : Install
-v : Verbose
-h : Human view (Hash Sign)
To Upgrade RPM:
#rpm –U rpm_name
To repair any corrupted rpm package
#rpm –F rpm_name
To make any rpm query
#rpm –q rpm_name
To check all rpm of related pacakes
#rpm –qa |grep rpm_name
To check particular file associated with which rpm
# rpm –qf /etc/passwd
passwd file is associated with setup-2.5 rpm
To check the rpm containing which file
#rpm –ql rpm_name
this command will list all the file associated with particular rpm.
To get the information about the particular rpm.
#rpm –qi rpm_name
To Install any rpm forely
#rpm –ivh rpm_name –force
Installing dependent packages:
Suppose we have 4 rpm’s r1,r2,r3 and r4 , we need to install r4 but r4 depends on remaining rpm’s then we use this command.
To check any rpm’s query
#rpm –qa “sendmail*”
To check rpm’s of related service
#rpm –qa |grep bind
Task Automation and Task Scheduling:-
It is used to perform the task at particular time
Two command are used
a. at
b. crontab
syntax:
#at time
at>command I
at>command II
ctrl+D
Example:
#at 10:30
at>eject
at>eject –t
ctrl+D
Option used
#at now
#at now+5 minutes
#at now+5 hours
#at now+5 days
#at tomorrow
#at 10:30 july 16 2006
we can also restrict the user not to use the ‘at’ command. Restriction will be provided by root login with administrator.
#vi /etc/at.deny
inside this file we have to just mentioned the name of the user in order to restrict him not to use ‘at’ command.
Just save and exit form the file
By
default all users are allowed to use ‘at’ command. ‘at.deny’ is default
in system. We can also create a file ‘at.allow’ file. Once we create
this file, now by default all users will be restricted to use ‘at’
command and only that user which have entry on ‘at.allow’ will allow to
use the ‘at’ command.
Another
method is to make an entry inside the ‘crontab’ file. Entry will be
done by the root. Difference between these two method is crontab is used
to perform the same task many times whereas job through ‘at’ command
will be removed after the task has been performed.
Syntax: ( By root login)
#crontab –e
six field are listed
1 2 3 4 5 6
minute hour day of Month day of command
month Week
Example:
35 10 31 05 3 eject
36 10 31 05 3 eject –t
Minute : 0-59
Hours : 0-23
Day of Month : 1-31
Month : 1-12
Day of Week : 0-7
0 and 7 are Sunday
#service crond restart
#whereis eject
this
command display the path of the command. It is better to use the full
path of the command inside crontab instead of just the name of the
command.
We can also make the entry as
35 10 * * * eject
36 10 * * * eject –t
In this case. These two jobs will be performed at 10:35 in every month.
Some
command which are executed with ‘at’ or ‘crontab’ send their output to
the user mail box. These command are executed on background and their
output is transferred to the particular user’s mail box. In order to see
the output of the command we use.
#mutt
This command will open the mailbox from where we check the output
Some of the switched used with the ‘crontab’
#crontab –l
List out all the job scheduled in crontab.
#crontab –r
Can remove the job from the crontab.
#atq : list the job number scheduled in at
#atrm jobno : to remove any job
Thanks ,
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