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======Systems Programming Journal======
====feb/11/16====
Been trying to figure this out for a bit to be honest im still not sure if this is the correct place to write this.

working on chmod...
====feb/17/16====
Some how lost my last post so i will be rewriting this entry again. 
In short it's about recent security vulnerabilities discovered 
by google's security team, and the redhat linux security team.

This vulnerability code named 'GHOST' can be found in gcc libraries such as glibc.
The GHOST vulnerability is a critical issue as it allows for an attacker to
cause a buffer overflow on a system(overflowing the allocated space for specific memory address allowing for varius kinds of attacks for example leaking vital information about what the system might be running or what is in memory, then possibly push byte code into the leaked address space that could execute code *backdoor?/trojan?* im not completely knowledgeable on the subject but it doesn't sound good. 

I'm posting this here because i realized that upon testing my system for this vulnerability I found the code i was writing was using good old c programming, and he skills and abilities i'm currently learning in this class.

// bellow is the sites where i got the information discussing the issue.
http://arstechnica.com/security/2016/02/extremely-severe-bug-leaves-dizzying-number-of-apps-and-devices-vulnerable/

// testing your system
https://www.linode.com/docs/security/security-patches/patching-glibc-for-the-ghost-vulnerability
====feb/23/16====
new project computing primes we will compute primes normally then optimise the code to run better.

learned about buffer overflows and exploits due to depricated functions like gets.

talked about heartbleed, shellshock, ghost 

see xkcd.com/327, xkcd.com/1354
====feb/25/16====
learning about concurrence/ performance multitasking
"fork" - create a child process/child (a duplicate of the child)
must "#include <unistd.h>"
if the child loses connection from the parent it becomes a zombie.
fork returns 0 if the object is a child, and 1 if it is a parent.

another function to note is "clone" 
another is "exec" this allows you to run other programs in your code.

example of "fork()" usage found in ~/system/forky.c
example usage ~/system/forky2.c (run useing forky2 int numofchildren, int numofprocessestotal.

====mar/08/16====
today we talk about sorting 
<nowiki>
bubble 
insert - simple sorts
select 
</nowiki>

quick sort
heep  sort
merge sort

side note made new optimizations to primeoptnew.c it now has a final time of 2.436986 useing the input 4194304
this was done useing seives, sqrroot, logic optimization
instaed of 
<code>
while(num <= num2){/*code goes here */num++;}
i use 
while((num++ * num)<= num2/80){//code goes here}
</code>
the 80 is a option optimization, and and when using 'num++'
be aware of off by one situations.
the iteration happens right after the close ')' 
so any corresponding num used after needs to be adjusted accordingly.

===== mar/10/16 =====
for information of sockets get a unix linux book by bruce molle.

Today we skipped pipes and shared memory to talk about sockets im pretty sure im not ready for this as i dont understand fork() yet...

we will be using the tcp protocol for ease of use in debuging.

===== mar/15/16 =====
use nc or telnet as browser

nc www 80
local host /portnum

===== mar/24/16 =====
today we are learning about stty typing stty -a in a terminal
will display a list of commands.

stty echo turns text displaying off.

stty istrip for higher value ASCII symbols.

todays code 
/systems/size.c
/systems/echostate.c

man ioctl_list for a list of io constants for hard ware devices.
==== april/5/16 ====
things i did on break. lost acess to the great www due to moving to a new house . got my own room now and have a desk so i can now do my work more comfortable. planed to work on my game but life got in the way.
==== april/5/16 ==== 
today in class learning about pipes.
uses stacks and queues to relay information.
==== APRIL/7/16 ====
Today we learned about signal trapping. 
example run 
a sigup 

and i forgot to log out
==== April/12/16 ====
learning about shared memory files : systems/shmfun.c , and systems/shmsay.c for examples.

lol this turned into the weirdest messenger client.
side note for getto chat client example can be fount in systems/shmchat.c
almost finished it seems to be having an issue writing the 4th chat file.
==== April/29/16 ====
Awesome logic trixx using xor, or xnor
xor uses ^ in c 
xnor probably uses !^ in c 
xor when used like this will swap numbers
a = 7  = 0111
b = 10 = 1010
a= a xor b
a= 1101

b= a xor b
b= 0111

a= a xor b
a= 1010
 
xnor used for checking equivalence
ex:
1010
0111
------
0010   not equal because not all 1

1010
1010
-----
1111  equal  
==== 
For more info on key board find user
include ncurses.h.
created a drawing app using ncurses.
file located in systems/ncurses/cursorie.c
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