Sample vimrc file

For vimdiff colorschemes:

- Download github & molokai like below

curl -fLo ~/.vim/colors/molokai.vim --create-dirs https://raw.githubusercontent.com/tomasr/molokai/master/colors/molokai.vim
curl -fLo ~/.vim/colors/github.vim --create-dirs https://raw.githubusercontent.com/endel/vim-github-colorscheme/master/colors/github.vim

Then add the below in .vimrc file

if &diff
"   colorscheme github
    colorscheme molokai
endif

<or> ":colorscheme github" diff mode

syntax enable
set incsearch
set nocompatible
set showcmd
set hlsearch
set ai
set si
set ts=4 sw=4 smarttab
set nu
"set nowrap
set formatoptions+=r
set softtabstop=4
set smartindent
set autoindent
set showmatch
"set cursorline

source $HOME/.vim/plugin/taglist.vim
source $HOME/.vim/plugin/comments.vim

"highlight DiffAdd term=reverse cterm=bold ctermbg=white ctermfg=black
"highlight DiffChange term=reverse cterm=bold ctermbg=cyan ctermfg=black
"highlight DiffText term=reverse cterm=bold ctermbg=gray ctermfg=black
"highlight DiffDelete term=reverse cterm=bold ctermbg=cyan ctermfg=black

nnoremap <silent> <F1> :TlistToggle<CR>
"map <C-v><C-v> : vs<cr>
"map <C-q> : q<cr>

command CDC lcd %:p:h

hi LineNr   ctermfg=darkyellow
"hi Function ctermfg=cyan
hi Function ctermfg=yellow
"hi Type  ctermfg=cyan
hi Type  ctermfg=lightred
hi String ctermfg=darkgreen
"hi String ctermfg=150
hi Number ctermfg=brown
"hi Operator ctermfg=brown
hi Search ctermbg=yellow
hi Conditional ctermfg=green
hi Comment ctermfg=lightblue
"""
"if &term =~ "xterm\\|rxvt"
  " use an orange cursor in insert mode
  "let &t_SI = "\<Esc>]12;orange\x7"
  " use a red cursor otherwise
  "let &t_EI = "\<Esc>]12;red\x7"
  "silent !echo -ne "\033]12;red\007"
  "" reset cursor when vim exits
  "autocmd VimLeave * silent !echo -ne "\033]112\007"
  " use \003]12;gray\007 for gnome-terminal and rxvt up to version 9.21
"endif
highlight Cursor ctermfg=yellow ctermbg=black
"highlight iCursor guifg=white guibg=steelblue
"set guicursor=n-v-c:block-Cursor
"set guicursor+=i:ver100-iCursor
"set guicursor+=n-v-c:blinkon0
"set guicursor+=i:blinkwait10
"""

" Copyright abbreviations

iab cfn /*<CR>Function<CR><CR>Description<CR><CR>Parameter(s)<CR><CR>Return Value<CR>/<Up><Up><Up><Up><Up><Up>

iab todo // TODO Remove this

iab cpr Broadcom Proprietary and Confidential. Copyright © 2019 Broadcom.<CR>All Rights Reserved.<CR>The term “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.

iab testbin TOPDIR<TAB>= ../../..<CR>MAKEDIR<TAB>= $(TOPDIR)/make<CR><CR>include $(MAKEDIR)/Tools.make<CR>include $(MAKEDIR)/Targets.make<CR>include $(MAKEDIR)/Fabos.make<CR>include $(MAKEDIR)/Man.make<CR><CR>TESTBIN = testbin<CR>TESTBIN_SRCS = testbin.c<CR>TESTBIN_OBJS = $(TESTBIN_SRCS:.c=.o)<CR><CR>$(TESTBIN): $(TESTBIN_OBJS)<CR><TAB>$(CC) $(LDFLAGS) -o $@ $^ $(LDLIBS)<CR>all:: $(TESTBIN)<CR><CR>clean::<CR><TAB>rm $(TESTBIN) $(TESTBIN_OBJS)

iab log_this #define LOG_THIS(format, ...) { \<CR>if (access("/harish", F_OK) != -1) { \<CR>char buf1[128] = {}; char buf2[256] = {}; \<CR>char tbuf[20] = {}; time_t now = time(0); struct tm *sTm = gmtime(&now); \<CR>strftime(tbuf, sizeof (tbuf), "%Y-%m-%d %H:%M:%S", sTm); \<CR>snprintf(buf1, sizeof (buf1), "[%s %s:%d]" format, tbuf, __func__, __LINE__, ##__VA_ARGS__); \<CR>snprintf(buf2, sizeof (buf2), "echo '%s' >> /harish_log", buf1); \<CR>system(buf2); } }

function! LoadCscope()

  let db = findfile("cscope.out", ".;")

  if (!empty(db))

    let path = strpart(db, 0, match(db, "/cscope.out$"))

    set nocscopeverbose " suppress 'duplicate connection' error

    exe "cs add " . db . " " . path

    set cscopeverbose

  " else add the database pointed to by environment variable

  elseif $CSCOPE_DB != ""

    cs add $CSCOPE_DB

  endif

endfunction

"au BufEnter /* call LoadCscope()

" http://cscope.sourceforge.net/cscope_maps.vim
nmap <C-\>ss :cs find s <C-R>=expand("<cword>")<CR><CR>
"nmap <C-\>g :cs find g <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>cc :cs find c <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>tt :cs find t <C-R>=expand("<cword>")<CR><CR>
"nmap <C-\>e :cs find e <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>ff :cs find f <C-R>=expand("<cfile>")<CR><CR>
"nmap <C-\>i :cs find i ^<C-R>=expand("<cfile>")<CR>$<CR>
"nmap <C-\>d :cs find d <C-R>=expand("<cword>")<CR><CR>
nmap <C-\>s :cs find s
nmap <C-\>g :cs find g
nmap <C-\>c :cs find c
nmap <C-\>t :cs find t
nmap <C-\>e :cs find e
nmap <C-\>f :cs find f
nmap <C-\>i :cs find i
nmap <C-\>d :cs find d

" quick fix options
nmap qf :set cscopequickfix=s-,c-,d-,i-,t-,e-
nmap noqf :set cscopequickfix=""
nmap cw :cwindow

"function! AddCscope()

    "echom "Adding CSCOPE file.. please wait"

    "silent! exec "r!goto_base_ws"

    ":cs add cscope.files

"endfunction

"nnoremap <silent> <F3> :call AddCscope()<CR>

"nnoremap <F3> :! ~/bin/goto_base_ws && cd vobs/projects/springboard/fabos <CR>:cs add cscope.files<CR>

To find out the location of the missed calls you got

http://site3.way2sms.com/jsp/LocateMobile.jsp

Socket Programming - Part 1

Reference: http://www.tenouk.com/cnlinuxsockettutorials.html

Port Numbers

• 16 bit integers
• So a maximum port numbers are 2^16 = 65536 (0 to 65535)
• Unique with a machine/IP address
• Each service/application/daemon will have their own port number 
• Required to make a connection (along with its host IP address)

Server & Client Port Numbers

• Connection is defined by: (Server IP and Port number) + (Client IP and port number)
• Server Port numbers are low numbers in the range 1 - 1023 (called as WELL KNOWN PORT NUMBER)
• Accessible only by Administrators (roots, in linux)
• Used for authentication
• A server running on a well-known port lets the OS know what port it wants to listen on
• Normally, client port numbers are higher number starting at 1024
• Client normally simples lets the OS picks a new port that is not already in use.

Background and Foreground Process

1. When you run a command (process), you can make it to run as a background process using $<cmd> &
2. If you forget to make that command as background, and if you feel you should do it now, then
- Press CTRL+Z (Suspend that process)
- $> bg disown 1 (make that process to be a background
3. Now if you want to check the list of background processes, type $> jobs
4. If you want to bring the background process to foreground, then type
$> fg %1
Again to make it a background process,
$> bg %1

When properties screwed up

When Properties got screwed up in Visual Studio 2005/2008, in the cmd, type "devenv /resetskippkgs".
It will get you the default properties (color, font etc) for your editor. 

Late/Dynamic Binding in C++

Late Binding using Function Pointers (C)

Locks in Multi-processing/multi-thread programming

DeadLock:
A deadlock is a situation wherein two or more competing actions are each waiting for the other to finish, and thus neither ever does.


LiveLock:

A livelock is similar to a deadlock, except that the states of the processes involved in the livelock constantly change with regard to one another, none progressing. Livelock is a special case of resource starvation; the general definition only states that a specific process is not progressing.

A real-world example of livelock occurs when two people meet in a narrow corridor, and each tries to be polite by moving aside to let the other pass, but they end up swaying from side to side without making any progress because they both repeatedly move the same way at the same time.

Livelock is a risk with some algorithms that detect and recover from deadlock. If more than one process takes action, the deadlock detection algorithm can repeatedly trigger. This can be avoided by ensuring that only one process (chosen randomly or by priority) takes action.

I2C protocol

http://www.i2cbus.com/theprotocol.html

new/delete operator

1. Return type of delete operator is void (not void*)




2. Exception and valid cases


char *p;

delete p; ==> exception (shown in picture)




Where as
char *p = 0;
delete p; .==> You can, however, use delete on a pointer with the value 0. This provision means that, when newreturns 0 on failure, deleting the result of a failed new operation is harmless.




2. Mixing both new/malloc and delete/free


class A {
public:
   A() { cout << "Constructor" << endl;
   ~A() { cout << "Destructor" << endl;
};


int main() {
  A *a = new A;
  free(a);                 ==> Calls only constructor; not destructor


 A *b = (A*)malloc(sizeof(A));
 delete b;               ==> Calls only destructor; not constructor


 A *c = new A;
 delete c;                ==> Calls both constructor and destructor
}                          

GDB unknown commands

All in gdb> prompt

1. Ctrl + p => To get the previous command
2. p array@sizeof(array) => To print all the array elements
3. set print pretty on => To print the structure elements' values in a neat way
4. p /x => prints the value in hexa decimal format