Hi Gang, I've been writing scripts, both for myself and for new users to linux, I have recently been working on a way to alter the grub menu appearance via terminal and I have stumbled up on a rut. I normally use sed to replace or alter a line in a system file(including /etc/default/grub itself), but sed -i -e '/GRUB_COLOR_NORMAL="light-gray/black"/c\GRUB_COLOR_NORMAL="white/black" ' /etc/default/grub for instance doesn't give me the desired effect. I have used several variations of sed commands to change them, but in the end, I'm lost. Please tell me where I might have went wrong.

you need to escape literal forward slashes (and possibly other characters) like this: \/

also, your problem description lacks basic troubleshooting procedure.

or, if you use / in your expressions you can use another delimiter.

It looks kinda like this right now.



color=$(sudo sed -i -e '/GRUB_COLOR_NORMAL="light-gray/black"/c\GRUB_COLOR_NORMAL="$color" ' /etc/default/grub)
Highlight=$(sudo sed -i -e '/GRUB_COLOR_HIGHLIGHT="green/black"/c\GRUB_COLOR_HIGHLIGHT="$Highlight" ' /etc/default/grub)
background=$(sudo sed -i -e '/GRUB_BACKGROUND="/usr/share/grub/background.png"/c\GRUB_BACKGROUND="$background" ' /etc/default/grub)
theme=$(sudo sed -i -e '/GRUB_THEME="/path/to/gfxtheme"/c\GRUB_THEME="$theme" ' /etc/default/grub)

echo "Choose a number between 1 and 5"

echo "1 - Changing the color"
echo "2 - Changing the Highlight"
echo "3 - Changing the background"
echo "4 - Changing the theme"
echo "5 - Doing all the above"

read customization;

case $customization in
1) sudo sed -i -e '/GRUB_COLOR_NORMAL="light-gray/black"/c\GRUB_COLOR_NORMAL="red/black" ' /etc/default/grub ;;
2) sudo sed -i -e '/GRUB_COLOR_HIGHLIGHT="green/black"/c\GRUB_COLOR_HIGHLIGHT="$Highlight" ' /etc/default/grub ;;
3) sudo sed -i -e '/GRUB_BACKGROUND="/usr/share/grub/background.png"/c\GRUB_BACKGROUND="$background" ' /etc/default/grub ;;
4) sudo sed -i -e '/GRUB_THEME="/path/to/gfxtheme"/c\GRUB_THEME="$theme" ' /etc/default/grub ;;
5) $color && $Highlight && $background && $theme
esac

please use [code]here comes your script[/code] tags to keep original formatting.

And it is now ok for you? Or is there any problem with that?

Your sample from post#1 can be improved like this
The s (substitute) command replaces only the right side.
The | delimiter does not clash with the / characters in the search and substitution strings.
A rather theoretic problem with this is, the /search/ can match on the right side and the |search| can match on the left side.
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