Ubuntu 21.10 更改登录界面背景

新建一个名为 change-gdm-background.sh 的文件，并复制如下内容，或者直接使用 archive 目录下已测试过的文件：change-gdm-background.sh

---

开始

#!/usr/bin/env bash

# Autor: Thiago Silva

# Contact: thiagos.dasilva@gmail.com

# URL: https://github.com/thiggy01/change-gdm-background

# =================================================================== #

  

# Check if script is run by root.

if [ "$(id -u)" -ne 0 ] ; then

echo 'This script must be run as root or with the sudo command.'

exit 1

fi

  

# Check what linux distro is being used.

distro="$(lsb_release -c | cut -f 2)"

if ! [[ "$distro" =~ (focal|groovy|hirsute|impish) ]]; then

echo 'Sorry, this script only works with focal, groovy or hirsute distros.'

exit 1

fi

  

# Check if glib 2.0 development libraries are installed.

if [ ! -x "$(command -v glib-compile-resources)" ]; then

echo 'Additional glib 2.0 libraries need to be installed.'

read -p 'Type y or Y to proceed. Any other key to exit: ' -n 1

if [[ "$REPLY" =~ ^[yY]$ ]]; then

apt install libglib2.0-dev-bin

else

echo "This tool can't run without required libraries"

echo "Exiting."

echo

exit 1

fi

fi

  

# Assign the default gdm theme file path.

if [ "$(lsb_release -i | awk '{print $3}')" == 'Ubuntu' ]; then

gdm3Resource=/usr/share/gnome-shell/theme/Yaru/gnome-shell-theme.gresource

elif [ "$(lsb_release -i | awk '{print $3}')" == 'Pop' ]; then

gdm3Resource=/usr/share/gnome-shell/theme/Pop/gnome-shell-theme.gresource

fi

  

# Create a backup file of the original theme if there isn't one.

[ ! -f "$gdm3Resource"~ ] && cp "$gdm3Resource" "$gdm3Resource~"

  

# Restore backup function.

restore () {

mv "$gdm3Resource~" "$gdm3Resource"

if [ "$?" -eq 0 ]; then

chmod 644 "$gdm3Resource"

echo 'GDM background sucessfully restored.'

read -p 'Do you want to restart gdm to apply change? (y/n):' -n 1

echo

if [[ "$REPLY" =~ ^[yY]$ ]]; then

service gdm restart

else

echo 'Restart GDM service to apply change.'

exit 0

fi

fi

}

  

# Restore the original gdm3 theme.

[ "$1" == "--restore" ] && restore

  

#Define main variables.

gdm3xml=$(basename "$gdm3Resource").xml

workDir="/tmp/gdm3-theme"

  

# Create directories from resource list.

CreateDirs() {

for resource in `gresource list "$gdm3Resource~"`; do

resource="${resource#\/org\/gnome\/shell\/}"

if [ ! -d "$workDir"/"${resource%/*}" ]; then

mkdir -p "$workDir"/"${resource%/*}"

fi

done

}

  

# Extract resources from binary file.

ExtractRes() {

for resource in `gresource list "$gdm3Resource~"`; do

gresource extract "$gdm3Resource~" "$resource" > \

"$workDir"/"${resource#\/org\/gnome\/shell\/}"

done

}

  

# Compile resources into a gresource binary file.

CompileRes() {

glib-compile-resources --sourcedir=$workDir/theme/ $workDir/theme/"$gdm3xml"

}

  

# Moves the newly created resource to its default place.

MoveRes() {

mv $workDir/theme/gnome-shell-theme.gresource $gdm3Resource

}

  

# Check if gresource was sucessfuly moved to its default folder.

Check() {

if [ "$?" -eq 0 ]; then

# Solve a permission change issue (thanks to @huepf from github).

chmod 644 "$gdm3Resource"

echo 'GDM background sucessfully changed.'

read -p 'Do you want to restart gdm to apply change? (y/n):' -n 1

echo

# If change was successful apply ask for gdm restart.

if [[ "$REPLY" =~ ^[yY]$ ]]; then

service gdm restart

else

echo "Change will be applied only after restarting gdm"

echo

fi

else

# If something went wrong, restore backup file.

echo 'something went wrong.'

restore

echo 'No changes were applied.'

fi

}

  

CleanUp() {

# Remove temporary directories and files.

rm -r "$workDir"

exit 0

}

  

ReplacingBg() {

oldBg="#lockDialogGroup \{\n?.*?\}"

if [[ "$distro" == "impish" ]]; then

perl -i -0777 -pe "s/$oldBg/$newBg/s" "$workDir"/theme/gdm.css

else

perl -i -0777 -pe "s/$oldBg/$newBg/s" "$workDir"/theme/gdm3.css

fi

}

  

# Test if argument is an image file.

if [[ $(file --mime-type -b "$1") == image/*g ]]; then

  

# Define image variables.

gdmBgImg=$(realpath "$1")

imgFile=$(basename "$gdmBgImg")

  

# Call procedures to create directories and extract resources to them.

CreateDirs

ExtractRes

  

# Copy selected image to the resources directory.

cp "$gdmBgImg" "$workDir"/theme

  

# Change gdm background to the image you submited.

newBg="#lockDialogGroup {

background: url('resource:\/\/\/org\/gnome\/shell\/theme\/$imgFile');

background-size: cover; }"

ReplacingBg

  

# Generate gresource xml file.

echo '<?xml version="1.0" encoding="UTF-8"?>

<gresources>

<gresource prefix="/org/gnome/shell/theme">' > "$workDir"/theme/"$gdm3xml"

for file in `gresource list "$gdm3Resource~"`; do

echo " <file>${file#\/org\/gnome/shell\/theme\/}</file>" \

>> "$workDir"/theme/"$gdm3xml"

done

echo " <file>$imgFile</file>" >> "$workDir"/theme/"$gdm3xml"

echo ' </gresource>

</gresources>' >> "$workDir"/theme/"$gdm3xml"

  

# Compile the new gresource.

CompileRes

  

# Move gresource to the default place.

MoveRes

  

# Check if everything was successful.

Check

  

# Remove temporary files and exit.

CleanUp

  

# Change background colors.

elif [[ "$1" =~ ^#([A-Fa-f0-9]{6}|[A-Fa-f0-9]{3})$ ]]; then

  

# Store selected background color.

BgColor="$1"

  

CreateDirs

ExtractRes

  

# Change gdm background to the color you submited.

  

newBg="#lockDialogGroup {

background: $BgColor;

background-size: cover; }"

ReplacingBg

  

# Generate the gresource xml file.

echo '<?xml version="1.0" encoding="UTF-8"?>

<gresources>

<gresource prefix="/org/gnome/shell/theme">' > "$workDir"/theme/"$gdm3xml"

for file in `gresource list "$gdm3Resource~"`; do

echo " <file>${file#\/org\/gnome/shell\/theme\/}</file>" \

>> "$workDir"/theme/"$gdm3xml"

done

echo ' </gresource>

</gresources>' >> "$workDir"/theme/"$gdm3xml"

  

# Compile the new gresource.

CompileRes

  

# Move gresource to the default place.

MoveRes

  

# Remove temporary files and exit.

CleanUp

  

else

  

# If no file was submited or file submited isn't an image,

# show this message.

echo 'Image file not found or wrong color hex code.'

echo 'Please, submit a .jpg or .png image file or a valid hex code.'

echo 'Usage: sudo ./ubuntu-20.04-change-gdm-background /path/to/image.*g'

echo 'Usage: sudo ./ubuntu-20.04-change-gdm-background \#yourhexcode'

  

fi