Feature Request: Include ISO Creation Date in GRUB menu entry #32

Hallo GRML Team,

some years ago I found grml-rescueboot and think it's also really good for fast and efficient booting of different other Linux live iso like Ubuntu daily live.

The tool isoinfo can extract the exact compilation/creation timestamp when using the -debug flag, even if the image is an isohybrid.

I propose updating the get_iso_identifier() function in /etc/grub.d/42_grml to optionally parse and append this creation date to the GRUB title if available.

Tried it on Ubuntu 24.04 and it's working fine so far booting Lubuntu 26.10 daily live iso.

Proposed code change to add Creation Date to GRUB entry:

get_iso_identifier() {
local iso="$1"
local id=
local date=
if isoinfo --version >/dev/null 2>&1 ; then
id=$(isoinfo -d -i "${iso}" | grep '^Volume id:' | sed -e 's/^[^:]*: //')
[ -n "${id}" ] || id=$(isoinfo -d -i "${iso}" | grep '^Application id:' | sed -e 's/^[^:]: *//')
date=$(isoinfo -debug -d -i "${iso}" 2>/dev/null | grep 'Creation Date:' | awk '{print $3$4$5}')
fi
if [ -n "${id}" ] && [ -n "${date}" ]; then
echo "${id} [${date}]"
else
echo "${id}"
fi
}