sed replace * in url with text in json file-CodePudding

I'm looking to change the value of a key in a json file

Example:

"House":"sample.house.city"

Need to change the word "sample" to something else.

I can do this with:

sed -i 's|sample.house.city|town-home.house.city|g' file.json

but there is no guarantee that "sample" is going to be the same every time.

I've tried:

sed -i 's|*.house.city|town-home.house.city|g' file.json

but it doesn't change.

Also tried:

sed -i 's|"*.house.city"|"town-home.house.city"|g' file.json

but that ends up like:

"sample"town-home.house.city"

Any recommendations on how to do this correctly?

CodePudding user response：

To match any word, you can use [[:alnum:]_]* (POSIX BRE) / [[:alnum:]_] (POSIX ERE):

sed -i 's|[[:alnum:]_]*\.house\.city|townhome.house.city|g' file.json

See the online demo:

#!/bin/bash
s='"House":"sample.house.city"'
sed 's|[[:alnum:]_]*\.house\.city|townhome.house.city|g' <<< "$s"

Output:

"House":"townhome.house.city"

Note you also need to escape dots that are used to match literal dots.

CodePudding user response：

Explanation

1st Capturing Group (\w )

\w matches any word character (equivalent to [a-zA-Z0-9_])

matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)

2nd Capturing Group (.house.city)

\. matches the character .

house matches the characters house literally (case sensitive)

\. matches the character .

city matches the characters city literally (case sensitive)

Global pattern flags

g modifier: global. All matches (don't return after first match)

\2 replace with the 2nd Captured Group (.house.city)

$ sed -E 's/(\w )(\.house\.city)/town-home\2/g' <<< '"House":"sample.house.city"'

"House":"town-home.house.city"

$ sed -iE 's/(\w )(\.house\.city)/town-home\2/g' file.json