Category Archives: howto

Avoid Getting Redirected to Country-Specific Versions of Google

Some tips for enjoy google

When you’re in another country, usually redirects to a local version of the Google page—like for France, or for Germany. Here’s how to easily visit the regular in another country.

All you need to do is head to The NCR stands for “No Country Redirect”, and it’ll take you back to the regular, English-speaking without all the local results. Note that it will redirect to, so if you don’t see the /ncr after you press Enter, that’s normal.

you can use the pws=0 parameter to disable personalized results (e.g

you can set another country geo location using the gl paramter (e.g

VIM skills

Merge multiple blank lines


Note: \_s match white space and blank lines

Grep by unicode character

# replace back slash(\) to front slash(/)

:help regexp for details about some specific syntax to select unicode characters with a regular expression in Vim.

|/\%d|  \%d \%d match specified decimal character (eg \%d123)
|/\%x|  \%x \%x match specified hex character (eg \%x2a)
|/\%o|  \%o \%o match specified octal character (eg \%o040)
|/\%u|  \%u \%u match specified multibyte character (eg \%u20ac)
|/\%U|  \%U \%U match specified large multibyte character (eg \%U12345678)

Git get back some commit from (no branch)

Sometimes you would find that you’re not on any branch when git branch, is described here. This usually happens when you’re using a submodule inside another project. Sometimes you’ll make some changes to this submodule, commit them and then try to push them up to a remote repository, for more details see here:

git branch
* (no branch)

But,, when checkout master, you’ll lost the specific branch named (no branch)

git branch
* master

So, how can we got it back again?

As long as you’ve not done a git gc, then you’ve not lost anything. All you need to do is find it again :) What do you get with:

git reflog # (the commit-ish will be on the first line)

That should show you what happened, and the id of the missing node(s).

To get back to it, just do a git checkout <commit-ish> and your old pseudo branch is restored. also your can merge the specific <commit-ish> to your master.

git checkout master
git merge <commit-ish>

CentOS how to tips

How to remove RPM packages with several dependencies

If you are using fedora, simply use this simple script but be careful when answering y/N:

yum remove $(rpm -qa | grep PACKAGENAME)

  • Change PACKAGENAME with your Package name
  • For disabling plugins just add --disableplugin=PLUGIN-NAME
  • If you can’t access the Internet, just add this options to the line above --disablerepo=*

Find out what files are in my rpm package

Use following syntax to list the files for already INSTALLED package:

The –v (verbose) option can give you more information on the files when used with the various query options.

rpm -ql package-name

Use following syntax to list the files for RPM package:

rpm -qlp package-name

Type the following command to list the files for gitlab*.rpm package file:

rpm -qlp gitlab-7.1.1_omnibus-1.el6.x86_64.rpm

See also: HowTo: Extract an RPM Package Files Without Installing It

Update yum repositories for CentOS, RHEL Systems

Get the latest yum repos from one of the two links below, selecting to match your host’s architecture:

# CentOS/RHEL 6, 64 Bit (x86_64):
rpm -Uvh

Then enjoy update with yum update yum-updatesd

Change CentOS language

vi /etc/sysconfig/i18n

check the lang is your expected, such as:

LANG="en_US.UTF-8"  <<-----

and re-login with you user/passwd, check it with command locale

Yum install/update with specific repository

# update git with rpmforge-extras repository
yum --disablerepo=base,updates --enablerepo=rpmforge-extras update git

Git submodule

add a submodule

git submodule add [-b <branch>] [-f|--force] [--name <name>] [--] <repository> [<path>]


git submodule add -b master --name wp-theme-twentytwelve wp-content/themes/twentytwelve

remove a submodule

Via the page Git Submodule Tutorial:

To remove a submodule you need to:

  1. Delete the relevant section from the .gitmodules file.
  2. Stage the .gitmodules changes git add .gitmodules
  3. Delete the relevant section from .git/config.
  4. Run git rm --cached path_to_submodule (no trailing slash).
  5. Run rm -rf .git/modules/path_to_submodule
  6. Commit git commit -m "Removed submodule <name>"
  7. Delete the now untracked submodule files rm -rf path_to_submodule

Also can use this script git-delete-submodule



test -z $submodule && echo "submodule required" 1>&2 && exit 1
test ! -f .gitmodules && echo ".gitmodules file not found" 1>&2 && exit 2

NAME=$(echo $submodule | sed 's/\/$//g')
test -z $(git config --file=.gitmodules submodule.$NAME.url) && echo "submodule not found" 1>&2 && exit 3

git config --remove-section submodule.$NAME
git config --file=.gitmodules --remove-section submodule.$NAME
git rm --cached $NAME

SVN commond tips

SVN undo files added

In Subversion, to cancel an svn add example_folder command before committing to the repository, do not use svn delete or svn remove or made-up stuff like undo or cancel.

Use the svn revert command:

svn revert -R example_folder

How to display a specific user’s commits in svn log?

svn log [SVNPath] --search <USERNAME> -l <LIMIT>

For example:

svn log . --search allex -l 100

Revert changes from specific commit / Undoing Changes

Attempt to revert some changes by a specific commit version: 854

svn merge -r 854:853 l3toks.dtx

Note: 注意版本号之间的顺序,这个叫反向合并 (reverse merger)


svn merge -c -854 l3toks.dtx

The two commands are equivalent.