sor: sensible quote and the like

[Artoria2e5]

• A few quotes are added back to remove the possibility of the shell even wasting time on trying to word-split
• read -r for no mangling of backslashes
• double-bracketed [[ ]] test for quote-free fun
• change echo to printf '%s\n' for robustness against strange names starting with a dash
• %q quoting for eval to guard against trivial injections

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[Artoria2e5]

CLA signed, how do I make it recheck?

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CLAs look good, thanks!

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