quickemu: Support $disk_format var for $disk_img

[gmt4]

This adds disk_format=${disk_format:-qcow2} variable that defaults to qcow2 format, so the vm.conf files can use $disk_format to specify the format of the $disk_img when this is different from the default qcow2.

[lj3954]

Could you not use the file extension in the disk_img variable to determine the correct format?

[gmt4]

Could you not use the file extension in the disk_img variable to determine the correct format?

yep, thanks for the suggestion. Instead of guessing, I just went with asking qemu-img info to do the guessing for me.

[TuxVinyards]

| gawk '/^file format: / {print $NF}'

| grep 'file format' | cut -d ':' -f 2 | tr -d ' '

Not everyone has gawk installed. I would suggest this to be more portable. It's also easier to understand ...

Edit:

Or, probably cleaner, | grep 'file format' | cut -d ':' -f 2 | tr -cd '[:graph:]' as this also removes the trailing linefeed

[gmt4]

@TuxVinyards Done!, thanks for spotting it, i just went with gawk as I saw another use of gawk in https://github.com/quickemu-project/quickemu/blob/master/quickemu#L1411

[TuxVinyards]

@TuxVinyards Done!, thanks for spotting it, i just went with gawk as I saw another use of gawk in https://github.com/quickemu-project/quickemu/blob/master/quickemu#L1411

Two wrongs don't make a right. Line 1411 has bad use of 'cat' as well. 😵‍💫

[TuxVinyards]

Probably needs a PR for 1411 etc too. Should be 'grep $file | grep ...' 🤣

[flexiondotorg]

Closed via #986