study notes

umask value

if the previous default permission for file is XXX,set the default permission to XXX &~ $value
perl Number 

$n = 1234; # decimal integer
$n = 0b1110011; # binary integer
$n = 01234; # octal integer
$n = 0x1234; # hexadecimal integer
$n = 12.34e-56; # exponential notation
$n = "-12.34e56"; # number specified as a string
$n = "1234"; # number specified as a string

use taglist to improve vim

1 download Exuberant ctags extract it, add the dir to PATH.

2 download taglist plugin extract it to ~/.vim/

3 restart vim,run :TlistOpen in vim

4 done 

you may want to read

taglist option manul 

useful settings of vimrc

example of vim setting 

set nobackup
set nu
set tabstop=4 " numbers of spaces of tab character
set shiftwidth=4 " numbers of spaces to (auto)indent
set ignorecase " ignore case when searching
behave mswin
"taglist

let Tlist_Sort_Type = 1 "list the tag by name alphabetic
let Tlist_GainFocus_On_ToggleOpen =1 "jump on one click
let Tlist_Auto_Highlight_Tag=1 "Automatically highlight the current tag in the taglist.
let Tlist_Auto_Update =1 "Automatically update the taglist to include newly edited files.
let Tlist_Exit_OnlyWindow =1 "Close Vim if the taglist is the only window.