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Accepted
Josef Klimuk
Asked: 2018-05-30 09:04:46 +0800 CST

Replacing a string with quotes selectively using sed

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I have a file.

$ cat file
"bar":  false
"foo":  false

I need to replace the word false with true only in the pattern "foo": false. The problem is quotes and spaces.

I thought about two ways:

  1. To isolate the whole pattern in some sort of qoutes/double quotes.
  2. To replace only such "false" which has a "foo" before it.

An example try of 2 option:

$ sed -i 's/\(.*foo\)/false/true\1/g' file

It failed.

command-line sed text-processing

1 Answers

  1. Best Answer

    Use an address. The quotes are not a problem if you single quote your sed expression

    $ sed '/"foo"/ s/false/true/' file
"bar":  false
"foo":  true

    If you really need to match the whole pattern, fine:

    $ sed '/"foo": *false/ s/false/true/' file
"bar":  false
"foo":  true

    * matches any number of the preceding character (space).

    You can use \s to also match tabs (any horizontal whitespace):

    sed '/"foo":\s*false/ s/false/true/' file

    Add the -i option after testing to modify the original file.

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