Fedora 16 - easy grub2 update

[axel2078]

I found online that a convenient way of updating grub2 without knowing the rather long command is to create a shorter alias to it. The command to update grub2 is

grub2-mkconfig -o /boot/grub2/grub.cfg

To make a global alias that is persistent after reboot, you can do this:

as root, open up /etc/bashrc like so

vi /etc/bashrc

Then, go to the end of the file and insert this line:

alias update-grub='grub2-mkconfig -o /boot/grub2/grub.cfg'

In theory, this change should be persistent after reboot and you should now be able to update grub by running update-grub as root or via sudo if you are in the sudoers file. However, this did NOT work for me, so this is what I did:

I created a file in /sbin called update-grub. I used vi but you can use whatever editor you want. Then I coded the file like so:

#!/bin/bash
# Custom file written to update grub - kpt

grub2-mkconfig -o /boot/grub2/grub.cfg

Then, I just did a chmod 750 on the file. Since /sbin is in root's path, I can invoke the command just by doing

sudo update-grub

I don't know why the alias trick didn't work, but this one definitely does.

[secipolla]

Interesting. I remember for some time now all bash aliases I set didn't work (when using Debian too). I think I tried for update-grub too (in /root/.bashrc) and it didn't work.
I made a script like yours in /usr/local/bin but the issue I have is that I sometimes have to try two or three times for the console to run it (like opening other root bash sessions), usually two.

[axel2078]

Originally Posted by secipolla

Interesting. I remember for some time now all bash aliases I set didn't work (when using Debian too). I think I tried for update-grub too (in /root/.bashrc) and it didn't work.
I made a script like yours in /usr/local/bin but the issue I have is that I sometimes have to try two or three times for the console to run it (like opening other root bash sessions), usually two.

I haven't had this problem. Make sure you put your script somewhere in root's search path, but I'm pretty sure /usr/local/bin is. If you add yourself to the /etc/sudoer's file, you should just be able to

sudo update-grub

[secipolla]

Here's how I 'solved' it and maybe it's the 'proper' way of doing it (although a custom script should have worked properly as well):

Create /etc/profile.d/update-grub.sh with just this in it:

alias update-grub='grub2-mkconfig -o /boot/grub2/grub.cfg'

(I don't know how to make it available in the same session, but in a next session it works)

[sea]

Why not invoke the sudo command to the alias itself?
Like:

alias upd-grb2="sudo grub2-mkconfig -o /boot/grub2/grub.cfg"

... and place that alias in /etc/bashrc ?

EDIT:
Note to above post, placing a script in /etc/profile.d is a damm good way to slow down your operations
Those script gets called upon every console window opening, nbew console tab, login, logout.. etc.. bet you got the picture now

[secipolla]

Hi, sea.
Regarding the sudo thing, I don't use it.
I said that that could be the 'proper' way of doing it based on what I read on those files' headers. For instance, /etc/bashrc:

# /etc/bashrc

# System wide functions and aliases
# Environment stuff goes in /etc/profile

# It's NOT a good idea to change this file unless you know what you
# are doing. It's much better to create a custom.sh shell script in
# /etc/profile.d/ to make custom changes to your environment, as this
# will prevent the need for merging in future updates.
.
.

I see about the scripts being called, but I tried placing an alias in /root/.bashrc and IIRC it didn't work.

[sea]

To place scripts in /etc/profile.d is only a good idea, if those scripts contain variables only.
If they contain actions, its the worst location to place them.

But you're right, the 'saver' way to place an alias, could be by writing the alias to a custom.sh which will be placed in /etc/profile.d.

Aliases placed in /root/.bashrc are only loaded if you 'login' (su) to root.
AFAIK, alias' in that file, will be available only if you had loged into su/root.

Late note....
Oh darn, i havent seen you wrote an alias too.. thought you execute the command with that file.. my bad.

[glennzo]

There is no reason an alias in your home .bashrc file wont work. I use several aliases in mine. Make sure you are in your home folder with the pwd command

PHP Code:

[glenn@b-satellite17 ~>$ pwd
/home/glenn 


Edit the .bashrc file.

vi .basrc  < --- Don't overlook the dot before the word bashrc
alias fuzzbomb='sudo grub2-mkconfig -o /boot/grub2/grub.cfg'

Save and exit. Source the file so the alias will be recognized.

PHP Code:

source ~/.bashrc 


Try the alias

PHP Code:

fuzzbomb
<password> 


Should work just fine.

[PabloTwo]

alias fuzzbomb='sudo grub2-mkconfig -o /boot/grub2/grub.cfg

Should work just fine.

No, not without adding the closing single quote it won't.

[glennzo]

Dang. I saw that I missed that when I was writing the reply and still didn't add it. That's what you get for sitting in front of the TV with the laptop. Lack of attention to one or the other.

Interesting. When I just edited the post the single quote was there but it wasn't being displayed. Changed the PHP tags to CODE tags and it appears.