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mcExchange
Asked: 2015-08-18 06:23:27 +0800 CST

Replace text in file with variable using sed [duplicate]

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I need to replace a string in a file by another string which is stored in a variable.
Now I know that 

sed -i 's|sourceString|destinationString|g' myTextFile.txt

replaces a string but what if destination String was a combination of a hard coded string and a variable?

myString="this/is_an?Example=String"
sed -i 's|sourceString|${myString}destinationString|g' myTextFile.txt

The latter doesn't work, since $myString is not interpreted as a variable.

command-line

1 Answers

  1. Best Answer

    Bash doesn't interpret variables in single-quote strings. That's why that isn't working.

    myString="this/is_an?Example=String"
sed -i "s|sourceString|${myString}destinationString|g" myTextFile.txt

    Would work.

    Or if you need the single-quote for another reason, you can just butt strings together and they'll be intepreted as one:

    myString="this/is_an?Example=String"
sed -i 's|sourceString|'"$myString"'destinationString|g' myTextFile.txt
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