Using Sed to search and replace JSON using regex from stdin

Question

How would I use sed to search for the regex "pk": [0-9]+ in stdin and replace it with "pk": null ?

eg convert "pk": 123 to "pk": null

I've tried something like:

cat mydata.json | sed -e s/\"pk\"\:\s[0-9]+/\"pk\"\:\snull/g

but this has no effect. Cutting the regex back, it seems to break at [0-9]+ but I'm not sure why as this is both a simple and valid regular expression. What am I doing wrong?

Answer 1

这应该工作：

sed -e 's/"pk": [0-9]\+/"pk": null/g' mydata.json

Answer 2

the cat is not necessary.

sed 's/\(.*:\s*\)[0-9]\+/\1null/' file

if you need exactly pk :

sed 's/\("pk":\s*\)[0-9]\+/\1null/' file

eg

kent$  echo '"pk": 123'|sed 's/\(.*:\s*\)[0-9]\+/\1null/'
"pk": null