How to use shell regex command to split input line into tokens of decimals and operators?

user_6164172 0
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How to use grep/sed/awk to achieve this:

Input: a statement of decimals and numeric operators and parentheses, can have tab and spaces in between:

2 + 5* 61.2 -(32.5+7)/ 8

Output: a string, containing each token(either a decimal or an operator or parentheses), seperated by a single comma:

2,+,5,*,61.2,-,(,32.5,+,7,),/,8

Could regular expression + grep/sed/awk achieve this?

sed grep awk shell split
3 Answers
echo '2 + 5* 61.2 -(32.5+7)/ 8' |
sed -Ee 's:[0-9]+(\.[0-9]+)?|[-+*/()]:&,:g' \
    -e  's/[[:blank:]]+//g' \
    -e  's/,$//'

Gives:

2,+,5,*,61.2,-,(,32.5,+,7,),/,8

Global replace on a regex matching integers, decimal numbers, or one of the six characters -+*/(). Then remove tabs and spaces, and trailing comma.

user_139196680

You may use this sed solution:

s='2 + 5* 61.2 -(32.5+7)/ 8'
sed -E 's~[[:blank:]]*([0-9]+(\.[0-9]+)?|[+/*()-])[[:blank:]]*~\1,~g; s/,$//' <<< "$s"
2,+,5,*,61.2,-,(,32.5,+,7,),/,8
user_5482250 
$ sed -E 's/ |\t//g;s/([-\+\*\/)(])/,\1,/g;s/,+/,/g' <<<"2 + 5* 61.2 -(32.5+7)/ 8"
2,+,5,*,61.2,-,(,32.5,+,7,),/,8
user_41778280
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