What's proper way to extract number from a string and do math on it? e.g.
var="VmRSS: 181420 kB"
out=(numbers in $var)/1024 # expected 181420/1024 = 177.168 MB
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lucky1928
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What did you try? -[How much research effort is expected of Stack Overflow users?](https://meta.stackoverflow.com/questions/261592/how-much-research-effort-is-expected-of-stack-overflow-users) – 0stone0 Dec 13 '22 at 21:17
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https://stackoverflow.com/questions/17883661/how-to-extract-numbers-from-a-string – 0stone0 Dec 13 '22 at 21:21
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http://mywiki.wooledge.org/ArithmeticExpression – Gilles Quénot Dec 13 '22 at 21:22
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Note that the shell itself only does integer division, not floating-point. – Charles Duffy Dec 13 '22 at 21:35
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`[[ $var =~ ^[^[:digit:]]+([[:digit:]]+).*$ ]] && echo "scale=2; ${BASH_REMATCH[1]} / 1024" | bc` – David C. Rankin Dec 13 '22 at 21:39