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bashvariablesrootsubshell

Variables inside a bash script subshesll

I am trying to run commands as root and capture the output into a variable. However the variable "loopdev" is returning as empty.

sudo bash << "EOF"
whoami
loopdev=`losetup -f --show "${image}"`
echo "####" $loopdev "####"
EOF

The normal output for this command would be like below

$ image=sdimage.img
$ sudo losetup -f --show "${image}"
/dev/loop0
Solution

  • The solution was to pass in the image variable like this:

    image=rpi_2.img
sudo image="${image}" bash << 'EOF'
whoami
loopdev=`losetup -f --show "${image}"`
echo "####" $loopdev "####"
EOF

    Output:

    root
#### /dev/loop0 ####