Download and insert salt string inside wordpress wp-config.php with Bash

Question

How can I insert the content of the variable $SALT in a specific point (line or string) of a file like wp-contet.php from wordpress using Bash script?

Answer 1

If you have csplit available, you can split the original wp-config.php file either side of the salt definitions, download new salts, then cat back together. This keeps the PHP define() statements at the same location in wp-config.php instead of than moving them to a different location within the file:

# Download new salts
curl "https://api.wordpress.org/secret-key/1.1/salt/" -o salts

# Split wp-config.php into 3 on the first and last definition statements
csplit wp-config.php '/AUTH_KEY/' '/NONCE_SALT/+1'

# Recombine the first part, the new salts and the last part
cat xx00 salts xx02 > wp-config.php

# Tidy up
rm salts xx00 xx01 xx02