objdump

...Need to look it up...

[Important] static variable and static global variable

There might be a time, that you DID assigned some value to an static variable, but in a function somewhere else, the change cannot be detected. For example, I met this problem when using Software Timers (Particle) whose callback functions don't take any input parameters and return values. Therefore, global/static variables are the only way of communication to the callback functions.

Here is the reason:

(1) Global variables are stored in static region.(2*) Non-static global variable and static global variable are different where non-static global variable (just defined without keyword static) can be seen in all project source files while static global variable can only be seen in the source file where it is defined. 

So if I want some variables to be static and global, I should not put "static" in front of the definition otherwise functions in other source files cannot see it.

///////////////////////////////////////////////////////////////////////////////////////////////////////////

More, if coping with c++ objects...here are some tips.

(1) Dealing with Class/Object pointers:

First, variables declared as external must be defined. So you need to have

Logger *log;

in Logger.cpp. You can also initialize it there like this:

Logger *log = new Logger();

Second, you don't need any more declarations, that is you just need to include Logger.h, no need to declare another Logger variable in Foo.h, just use log from Logger.h.

(2) Dealing with objects

In .h file:
extern Timer _timerXXX;
extern Timer _timerYYY;
extern Timer _timerZZZ;

In .cpp file:
// give inputs to the constructors
Timer _timerXXX(x1, x2); 
Timer _timerYYY(y2, y2);
Timer _timerZZZ(z1, z2);

ref:
http://www.cnblogs.com/sideandside/archive/2007/03/29/692559.html
http://blog.csdn.net/ymangu666/article/details/22277673

ref more:
http://stackoverflow.com/questions/8362679/extern-pointer-initialization

Great Vim Configuration File

Found many online, but this one is perfect for me:


My Vim Configuration:
Mono-spaced small font suitable for a small laptop screen at 1280×800
“Desert theme” with dark background, 256-color palette
Some useful keyboard mappings
Use spaces as tabs (2 spaces = 1 tab), Smart indentation
Display line-numbers, Show matching braces when hover
Display all special characters (that is generally not supported in code files)
Auto-completion
Status-line modifications
Syntax-checking upon saving for almost all languages (plugins, see below)
File skeletons upon creation (plugins, see below)
Ignore CVS-, temporary and images (etc) files and directories
Disabled annoying sounds and bells (blinking)

Configuration:

" For Pathogen plugin manager
call pathogen#runtime_append_all_bundles()
call pathogen#helptags()

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
" Editing setings
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

" Enable filetype plugin
filetype plugin on
filetype indent on

" Filetypes and encoding
set fileformats=unix,dos,mac
set encoding=utf-8
set wildignore=.svn,CVS,*.o,*.a,*.class,*.mo,*.la,*.so,*.obj,*.swp,*.jpg,*.png,*.xpm,*.gif

" General behaviour
set autochdir      " CWD is always same as current file
set ai             " Autoident
"set si             " Smartident
set nowrap         " Do not wrap lines
set nocompatible   " ViM settings instead of Vi
set smartcase      " Smart casing when searching
set ignorecase     " ... or ignore casing
set hlsearch       " Highlight matches
set incsearch      " Modern (wrapping) search
set history=500    " Long undo history
set tw=1000

" make backspace a more flexible
set backspace=indent,eol,start

" Disable sounds
set vb t_vb="
set noerrorbells
set visualbell

" Tabbing, Default to 2 spaces as tabs
set cino=:0g0(0,W2
set expandtab
set tabstop=2
set softtabstop=2
set shiftwidth=2

" Filetype sesific
"au FileType python setlocal tabstop=4 softtabstop=4 shiftwidth=4

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
" User interface setings
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

syntax on
colorscheme desert

set showmatch                        " Show matching braces when over one
set ruler                            " Always show current position
set number                           " Always show line-numbers
set numberwidth=5                    " Line-number margin width
set mousehide                        " Do not show mouse while typing
set antialias                        " Pretty fonts
set t_Co=256                         " 256-color palletes
set background=dark                  " Dark background variation of theme
set guifont=Andale\ Mono\ 7.5          " Monospaced small font
set guioptions-=T                    " TODO
set guioptions+=c                    " TODO Console messages
set linespace=0                      " Don't insert any extra pixel lines
set lazyredraw                       " Don't redraw while running macros
set wildmenu                         " Wild menu
set wildmode=longest,list,full       " Wild menu options

" Display special characters and helpers
set list
" Show < or > when characters are not displayed on the left or right.
" Also show tabs and trailing spaces.
set list listchars=nbsp:¬,tab:>-,trail:.,precedes:<,extends:>

" Autocompletion
set ofu=syntaxcomplete#Complete
set completeopt+=longest,menuone
highlight Pmenu guibg=brown gui=bold
let g:SuperTabDefaultCompletionType = "<C-x><C-o>"

" Statusline
set statusline=%F%m%r%h%w[%L][%{&ff}]%y[%p%%][%04l,%04v]
"              | | | | |  |   |      |  |     |    |
"              | | | | |  |   |      |  |     |    + current
"              | | | | |  |   |      |  |     |       column
"              | | | | |  |   |      |  |     +-- current line
"              | | | | |  |   |      |  +-- current % into file
"              | | | | |  |   |      +-- current syntax in
"              | | | | |  |   |          square brackets
"              | | | | |  |   +-- current fileformat
"              | | | | |  +-- number of lines
"              | | | | +-- preview flag in square brackets
"              | | | +-- help flag in square brackets
"              | | +-- readonly flag in square brackets
"              | +-- rodified flag in square brackets
"              +-- full path to file in the buffer

" Highlight trailing whitespaces (+ keybindings below)
highlight ExtraWhitespace ctermbg=red guibg=red
highlight ExtraWhitespace ctermbg=darkgreen guibg=darkgreen
au InsertEnter * match ExtraWhitespace /\s\+\%#\@<!$/
au InsertLeave * match ExtraWhitespace /\s\+$/

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
" Plugins
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

" ViM highlighting
au BufNewFile,BufRead *.mxml set filetype=mxml
au BufNewFile,BufRead *.as set filetype=actionscript

" Highlight errors for VIM supported languages
" Supported languages are: ada, c, chill, csc, forth, groovy, icon, java, lpc, mel, nqc, nroff, ora, pascal, plm, plsql, python and ruby. The c settings also apply to cpp.
let c_space_errors = 1
let java_space_errors = 1
let python_space_errors = 1
let ruby_space_errors = 1

" NERDTree
noremap <F12> :NERDTree<CR>

" Tskel
let tskelUserName='Anders Evenrud'
let tskelUserEmail='andersevenrud@gmail.com'

" Syntastic
set statusline+=%#warningmsg#
set statusline+=%{SyntasticStatuslineFlag()}
set statusline+=%*
"SyntasticEnable php
"SyntasticEnable javascript
"SyntasticEnable xhtml
"SyntasticEnable python
let g:syntastic_enable_signs=1
let g:syntastic_auto_loc_list=1
"let g:syntastic_quiet_warnings=1

" CloseTag
autocmd FileType html,htmldjango,jinjahtml,eruby,mako let b:closetag_html_style=1
autocmd FileType html,xhtml,xml,htmldjango,jinjahtml,eruby,mako source ~/.vim/bundle/closetag/plugin/closetag.vim

" SuperTab
let g:SuperTabDefaultCompletionType = "context"

"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
" Key mappings
"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
inoremap <expr> <Esc>      pumvisible() ? "\<C-e>" : "\<Esc>"
inoremap <expr> <CR>       pumvisible() ? "\<C-y>" : "\<CR>"
inoremap <expr> <Down>     pumvisible() ? "\<C-n>" : "\<Down>"
inoremap <expr> <Up>       pumvisible() ? "\<C-p>" : "\<Up>"
inoremap <expr> <PageDown> pumvisible() ? "\<PageDown>\<C-p>\<C-n>" : "\<PageDown>"
inoremap <expr> <PageUp>   pumvisible() ? "\<PageUp>\<C-p>\<C-n>" : "\<PageUp>"

" RESIZE with numlock +-/*
if bufwinnr(1)
  map + <C-W>+
  map - <C-W>-
endif

"<home> toggles between start of line and start of text
imap <khome> <home>
nmap <khome> <home>
inoremap <silent> <home> <C-O>:call HHome()<CR>
nnoremap <silent> <home> :call HHome()<CR>
function! HHome()
 let curcol = wincol()
 normal ^
 let newcol = wincol()
 if newcol == curcol
  normal 0
 endif
endfunction

"<end> goes to end of screen before end of line
imap <kend> <end>
nmap <kend> <end>
inoremap <silent> <end> <C-O>:call HEnd()<CR>
nnoremap <silent> <end> :call HEnd()<CR>
function! HEnd()
 let curcol = wincol()
 normal g$
 let newcol = wincol()
 if newcol == curcol
  normal $
 endif
 "http://www.pixelbeat.org/patches/vim-7.0023-eol.diff
 if virtcol(".") == virtcol("$") - 1
  normal $
 endif
endfunction

"Ctrl-{up,down} to scroll. (gvim)
if has("gui_running")
 nmap <C-up> <C-y>
 imap <C-up> <C-o><C-y>
 nmap <C-down> <C-e>
 imap <C-down> <C-o><C-e>
endif

if bufwinnr(1)
  map <kPlus>  <C-W>+
  map <kMinus> <C-W>-
  map <kDivide> <c-w><
  map <kMultiply> <c-w>>
endif

" For highlighting trailing whitespaces
nnoremap <Leader>wn :match ExtraWhitespace /^\s* \s*\<Bar>\s\+$/<CR>
nnoremap <Leader>wf :match<CR>

" space / shift-space scroll in normal mode
noremap <S-space> <C-b>
noremap <space> <C-f>

ref:
https://anderse.wordpress.com/2011/09/07/my-vim-gvim-configuration/

permissions denied on serial port /dev/ttyACM0

Serial port is very commonly used when developing embedded systems such as Arduino or Particle core.

But we might encounter the following problem when trying to open the serial monitor:

                   Permission denied, cannot open /dev/ttyACM0

Many suggest to do:

              sudo chmod 666 /dev/ttyACM0

I don't know them but it did NOT work for me. This DID:

sudo usermod -a -G dialout boris

in which boris is my username.
And call:

      groups boris

to check.

Maybe you gotta login again.


Ref:
http://askubuntu.com/questions/616517/dev-ttyacm0-permission-denied-error
http://askubuntu.com/questions/58119/changing-permissions-on-serial-port

Open terminal by right click

Install nautilus-open-terminal. In a terminal type:

sudo apt-get install nautilus-open-terminal

Once it installs, type nautilus -q && nautilus & to quit and reopen nautilus, and check the right click option.

ref:
http://askubuntu.com/questions/293566/open-terminal-from-nautilus-by-right-click