Table of Contents

C/C++ Programming Journal

Jan 30, 2014

STDIN - Keyboard
STDOUT - Terminal
STDERR - Terminal
Printf(“”);
Fprintf(stdout,“
___”); == What Printf does.
00000000 = 0
11111111 = 255
0-255 = 256 unique values
Printf format specifiers
%d = signed int
%v = unsigned int
%c = ASCII character(char)
%s = array of character(string)
%f = floating point
%lf = double
%lu = unsigned long int
%hu = unsigned half/short int
%hhu = unsigned half half int
%x = hexidecimal %X = hexidecimal

0x00 = hexidecimal number
binary = 0,1
octal = 0-7
decimal = 0-9
hexidecimal = 0-9a-f

Feb 6, 2014

HexidecimalOctalUnsigned DecimalBinarySigned Decimal
0 00 00 0000 +0
1 01 01 0001 +1
2 02 02 0010 +2
3 03 03 0011 +3
4 04 04 0100 +4
5 05 05 0101 +5
6 06 06 0110 +6
7 07 07 0111 +7
8 10 08 1000 -8
9 11 09 1001 -7
A 12 10 1010 -6
B 13 11 1011 -5
C 14 12 1100 -4
D 15 13 1101 -3
E 16 14 1110 -2
F 17 15 1111 -1
UDBSD
low : 0 low:0000 low:-8
high : 15 high:1111 high:+7
qty : 16 qty:10000 qty:16

MSB - Sign Bit
0 - +
1 = -

Two's Complement:
0001

to\\

1110 #invert
+ 1 #add one
1111

01111111
0x7F

10000000
0x80

Mental Math

2 digit numbers end in 5

15^2 = 225\
square second number 1|5^2
25
time 1st number by next number up
1*2=2
=225

int input; #variable
printf(“Enter Value:”);
Scanf(“%d”,&input); #address oaddress of

Feb 27, 2014

March 6, 2014

for loop

for(i=13, i>2, i-=3)

i-=3 means i = i - 3

while - top-driven loop - 0 or more times
do while - bottom-driven loop - 1 or more times

while(condition) - no semi colon
{
do stuff
}

do
{
do stuff
}while(condition); always does one loop first

return type - int main(int argc, char **argv)
{
int x=4;
x = square(x);
return(0);
}

y = f(x) - X is a parameter

==Function Prototype== - int square(int);

look into recursion!

March 20, 2014

fgetc(stdin); = Gets Rid Of Enter As A Input! For Char Inputs!

printf(“%.4hhd - the four leaves to blank spaces before the output the . makes the spaces zero. if it was a -4 the two spaces would be after the output. hhd means half of a half of an integer - char.
a = 41
b = 4
printf(”%.*hhd\n“,b,a); The b allows 4 zeros before the 41 because b is set to 4, variable, can change!!

==Learning More With Arrays!!
Look at program array1

1
#include<stdio.h>
 
int main()
 {
   int i, scores[8], sum = 0, total;
   float average;
 
printf("How big is the array?");
scanf("%d",&total);
scores=(int*)malloc(sizeof(int)*total);
 
   for(i=0;i<total;i++)
{
   printf("Enter Test Score %d/%d: ",(i+1),total);
   scanf("%d",(scores+i));
}
for(i=0;i<total;i++)
{
sum = sum + *(scores+i);
      // or   scores[i] 
}             
average = sum/total;
    printf("average is: %3.2f\n",average);                                                          

April 10, 2014

gcc - C - .c
g++ - C++ - .C, .cc, .c++, .cpp

look in terminal for c++ starting program.

printf(“Hello, World!\n”); in C
std :: cout « “Hello, World!” « endl; in C++

scanf(”%d“ , &a); in C
cin » a; in C++

to use cin and cout MUST INCUDE #include<iostream>

This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.

As an aid, feel free to use the following questions to help you generate content for your entries:

MONTH Day, YEAR

This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.

As an aid, feel free to use the following questions to help you generate content for your entries:

HPC Fundamentals Journal

MONTH Day, YEAR

This is a sample format for a dated entry. Please substitute the actual date for “Month Day, Year”, and duplicate the level 4 heading to make additional entries.

As an aid, feel free to use the following questions to help you generate content for your entries:

Jan 28, 2014

wiki.debian.org/Xen

ssh root@10.80.2.180
aptitude update
aptitude upgrade
aptitude search "VIM" , "Xen"- example
aptitude install 

hypervisor - kernel - user space

uname -a

install VIM and xen-linux-system

used Xen wiki to make Xen boot first!

vi /etc/network/interfaces

changed files according to Xen wiki

vi /etc/default/xendomains

do guest behaviour changes

restart server,

reboot

login run

xm list
 xen-create-image --verbose --hostname=test --dhcp --vcpus=2 --pygrub --dist=wheezy --force
ssh root@10.80.2.197

== sign into my VM after ssh into lab46

Jan 29, 2014

Got the virtual machines up and running, had memory problem… Changed some of the ram sticks around and found the culprit and swapped it. The computer is up and running again. Re-created VM's!

Jan 30, 2014

Working with Virtual Machines, Mine being alex1. Installing packages such as Vim, bsdgames, etc. Learned how to run visual programs such as yahtzee by starting from the pod and running:

pod02:~$ ssh -X root@10.80.2.197

Created shortcuts in .bashrc such as

alias aps='aptitude search'
alias api='aptitude install'
alias apud='aptitude update'
alias apug='aptitude upgrade'

Created Blackbeard User. Made The .vimrc and edited it.

Feb, 2014

Changed root@10.80.2.197 to root@vm04 for my sign on.

Creating Servers and Blogs Using Nginx and pybloxsom

Feb,12 2014

Finally Got My Blog Up And Running!!! Figured Out The Flavours And Have The Nice 1024px! Check out http://vm04/cgi-bin/pyblosxom.cgi

March,18 2014

Learned to create passwordless logins!!
Learned to take dumps in a new way!!

scp id_rsa.pub root@backup01:alex - copied to my root directory
cat alex » .ssh/authorized_keys - put my user into authorized keys
chmod 600 authorized_keys - changed permissions
cat authorized_keys - view the key

Continued taking dumps!!
dump -0uan -f - / | gzip -9 | ssh root@backup01 “dd of=blackbeard.dump.gz”


xm create - alex1 or wilson - Starting VM
blackbeard@router.projects.lan - arg
the type “su” to become root.
Then “screen -x” to join screen session.

April,17 2014

Subnetcalc

on lab46

%s/252/192/ will change all the 252's into 192 in the vi.
4yy copy 4 lines in vi.
cw replaces text in vi.