My document has things ilke:
1 Some, words.* Some more words,
2 Some words,* Some more words.
How can I
A. Find all commas at the end of the lines and replace them with periods (not editing commas elsewhere)?
B. Find all commas before an asterisk* and replace them with periods?
Commas at end of paragraphs
Provided your comma is at end of a paragraph, i.e. not followed by a linebreak created with Shift+Enter, use the following regular expression:
,$ = comma (your target) and dollar which is a descriptor for end-of-paragraph
The replace string is only a full stop.
Commas followed by a linebreak
In this case the regular expression is ,\n = comma and \n which is a descriptor for a linebreak
Commas before an asterisk
The regular expression is ,\* where the asterisk is escaped with a reverse solidus otherwise it means repeat 0 or more times the previous character. Your replace string is .* = full stop and asterisk. If you don’t want to keep the asterisk, just omit it in the replace string.