Modify the conf file through sed

such as , We need to change postgresql Medium postgresql.conf In the document password_encryption The attribute is md5.

$ grep password postgresql.conf
#password_encryption = scram-sha-256 # scram-sha-256 or md5

It can be as follows sed Order to modify

sed -i -E 's/^#?(password_encryption = )\S+(\s+#.*)/\1md5\2/' /tmp/postgresql.conf

among -E Indicates that regular expressions are enabled

1. #? Indicates that the configuration may be notes diaol
2. (password_encryption = ) Indicates that you need to match key value
3. \S+ Indicates that the replacement is not empty value value
4. (\s+#.*) Indicates the reserved subsequent annotation content