Swapping split windows in VIM

  Ctrl-W r will rotate the split windows in VIM

vim showing all opened files using sp/vsp

showing all opened files in vim
in vimrc file paste the below line
map <F4> :ls<CR>:buffer<space>

after opening the files in vim, type F4 and you can see the files and jump by pressing the corresponding the number

Android Hidden phone informations

1) *#*#4636#*#*
give you details about phone details like below

• Phone Information
• Battery INformation
• Usage Statistics
• Wi-Fi Information

2) To get IMEI : *#06#  works with types of mobiles

printing hex values in linux kernel module

for printing the hex values in the kernel modules/kernel space we can use the print_hex_dump function

the format is as follows

print_hex_dump("KERN_ERROR", "Message: ", DUMP_PREFIX_OFFSET,
                            16, 2, data_buffer, length_of_buffer, 1);

vim converting tabs to spaces

For converting tabs to spaces while editing the source codes

1) To insert space characters whenever the tab key is pressed.

 :set expandtab

2) To control the number of space characters that will be inserted when the tab key is pressed, set the 'tabstop' option.
To insert 4 spaces for a tab, you have to type the below command

:set tabstop=4

ctags useful tips

first run in the base directory ctags -R

In VI/VIM below commands can be used
Ctrl-] - go to function definition
Ctrl-T - Jump back from the definition.
Ctrl-W C-] - Open the definition in a horizontal split

useful git diff commands for developers

1) git diff with only file name and its status

git diff --name-status<commit_id> 

2) Showing differences introduced by a commit

git show <commit_id> 

3) Showing differences introduced by a commit with file name only, status of each file with commit message
git show --name-status <commit_id> 

4) Showing differences introduced by a commit with file name only, status of each file
git diff-tree  --name-status -r  <commit_id>