bashscriptingbinaryuudecode

How can a bash script write out a binary file, without using uudecode?


I've got a little puzzler here for the bash scripting experts... I have a bash script that needs to create a small (80 byte) binary file when it runs. The contents of the file need to be contained inside the script itself (i.e. I don't want to just package the file along with the script).

My script currently does it like this:

echo 'begin-base64 644 dummy.wav' > /tmp/dummy.uu
echo 'UklGRkgAAABXQVZFZm10IBAAAAADAAEAAHcBAADcBQAEACAAZmFjdAQAAAAAAAAAUEVBSxAAAAAB' >> /tmp/dummy.uu
echo 'AAAAQDYlTAAAAAAAAAAAZGF0YQAAAAA=' >> /tmp/dummy.uu
echo '====' >> /tmp/dummy.uu
uudecode -o /tmp/dummy.wav /tmp/dummy.uu
rm /tmp/dummy.uu

... after the above runs, I have my file /tmp/dummy.wav. But I just found out that the computer this script is to run on does not have uudecode installed (and I'm not allowed to install it), so I need to find some other way to create this file. Any ideas?


Solution

  • Some installers do something similar to this:

    #!/bin/bash
    tail -n +4 $0 | tar xvzf -
    exit
    <tgz file appended here><newline>