note2

Managing Software

Package Concepts
-Linux package managemnet tools are intended to help build and modify this programs based on:
1. Package = contain information about software packages, 
	-usually distributed as single files
	-once installed in consist of dozens or hundreds of files
	-incluse additional information for package management systems
2. Installed File Database = include all information about every file installed via package system,

3. Dependencies = requirements of package for one another

4. Checksums - used to verify the validity of the installed software

5. Upgrades and Uninstallation = package management systems will track upgrades and uninstall

6. Binary package Creation = got tools to create package form source code. 


USING RPM!!

-Red hat package management 
-been used by many linux Distro
RPM PACKAGE = packagename-a.b.c-x.arch.rpm

Above contain
-Package name
-Version Number
-Build number
-Architecture

In Ideal world RPM will install and run on any RPM distro that uses an appropriate CPU type.BUT!!!
-distro may be use other version of RPM
-RPM designed for other distro maybe using a different library
-distro maybe named the package differently
-sometimes package contain slightly different file
-some programs contain disto-specific file or script/configuration

IT safe to use YUM(Yellow Dog Updater) to install rpm package!

rpm = red hat package manager
-i =install
-U = Upgrade
-e = uninstall
q = query
-V = verify
-f = freshen
--rebuild = build binary package
--rebuilddb = rebuild rpm database to fix errors
++++++++
--force = force installation
-h = show progression
-v = perform uniform hash
--nodeps = no dependency checks
--test = check dependency conflicts.and other problems
-a = veifies all ackages
.
.
.

yum = rpm meta-packager ( make life more easy)
=install
=update
=check-update
=upgrade
=remove
=list
=search
=provides
=info
=clean
=shell
=resolvedep
=localinstall
=localupdate=deplist

yum configuration FIles
/etc/yum.conf
repos
/etc/yum.repos.d

Using Debian Packages

dpkg
-i = install
--configure = configure installed package
-r = remove packages but leave conf
-P / --purge = remove package including ,conf files
--get-selections =display currently installed package
-p = Display indoramtion about and installed package
-T = display information about an uninstalled package
-l = list installed package with pattern
-L = list the installed files associated with a package
-S = locates the packages that own the files
-C search for partially installed packages and suggests what to do with them

apt-cache = database program 
apt-cache showpkg = display information about package
apt-cache stats = learn how many packages you've installed,
apt-cach unmet = show missing libraries or files
apt-cache depends = shows all of the specified packages dependencies.
apt-cache pkgnames = displays the names of all the packages installed on the system.

apt-get =meta-packaging tools for Debian

=update
=upgrade
=dselect-upgrade
=dist-upgrade
=install
=remove
=source
=check
=clean
=autoclean
+++++++
-d = download only
-f = fix a system on which dependencies is not statisfied
-m = ignore missing
-q = quiet omit progress indicator
-s = simulate 
-y = produce yes for all prompt
-b = compile source package
--no-upgrade = not upgrade if the olader version is already installed


dslect,aptitude, Sypnatic = interactive text-based meta-packager
dpkg-reconfigure = use to reconfigure package(postfix etc.)

Debian package contain extra files for signature!

cfg file
/etc/dpkg/dpkg.cfg
source list
/etc/apt/sources.list


Converting between Package Formats
!
Use alien

alien = use to change oackage file to other format

--to-deb
--to-rpm
--to-slp
--to-tgz

rpmbuild = to rebuild an RPM source to package



ldd = check which libraries the programs files uses.

ldconfig = update library cache
-v = verbose
-N = dont rebuild cache, just update link
-x = opposite of -N rebuild cache not updating links
-f = change library default path
-C = change cache file
-r = treat dir as a root
-p = cause ldconfig to display the  current cache

uname =show kernel information
-i = hardware
-s = kernel
-v = version
-r = release
-p = processor
-o = operating system
-n = node
-m = machine

ps = show process information
a= show all
u= show user process
e/A = show all system processes
x= display all process for user who give command
--forest = show process in linked

top = Dynamic variant of ps
-delay = specifes delay between update
-p = monitor specific processies
-n = tek number of updates
-b = batch mode ,

keymode
k = kill process
q = quite from top
r = change process prioritu
s = change display update rate
P = sets the display to sort by CPU ussage
M = sets the display to sort by Memory usage

jobs = display minimal information about the processes associated with the current sessions

pgrep = find PID easy!
-u = specifies user 

fg = bring app to foreground
Ctrl +Z = bring to back
bg = runngin in the background

Manage proccess Priorites

nice = change program priorities
- = use minus
-n = chnage the priorities
--adjustment = change the priorities
!use 10 as default
-20 ~ 19 is posibble value
default priorities is 0

renice = change process priorites and need pid

exp 
renice 7 16580 -u pdavison tbaker


Killing Processes
- to kill process we send signal


kill = kill processes by specifing signal and pid

-s =signal

SIGKILL=9 cause the process ot exit without performing routine shutdown tasks
SIGHUP==1 terminate interactive programs and cause many daemons to reread their configuration files
SIGTERM=15 causes the process to exit but allows it to close open files and so on

-if you not specifiying signal default is 15=SIGTERM

*nohup = make the program to ignore SIGHUP

killall = kill a process bsed on its name rather thatn its PID

-i = interactive

pkill = allow you to kill one or more processes based on usernames,user id or group ID