self-extracting shell script

self-extracting_script.sh

# create files in an otherwise empty directory
mkdir files
cd files
touch setup.sh # entry point after extraction
touch file.txt # supporting data used by setup.sh

# create archive
tar -pczf ../archive.tar.gz *
cd ..

# create self-extracting script
cat <<EOF > install.sh
#!/bin/sh
cd \$(dirname \$0) && mkdir -p install && tail -n+4 \$0 | base64 -d | tar -pzxf - -C ./install && cd install && ./setup.sh >setup.log 2>&1
exit \$?
EOF

# append archive
base64 -w 0 archive.tar.gz >> install.sh
chmod ug+x install.sh

# test
mkdir test
cp install.sh test/
cd test
./install.sh