The "grep" command:
Usage: fossil grep [OPTIONS] PATTERN FILENAME ...
Attempt to match the given POSIX extended regular expression PATTERN
historic versions of FILENAME. The search begins with the most recent
version of the file and moves backwards in time. Multiple FILENAMEs can
be specified, in which case all named files are searched in reverse
chronological order.
For details of the supported regular expression dialect, see
https://fossil-scm.org/fossil/doc/trunk/www/grep.md
Options:
-c|--count Suppress normal output; instead print a count
of the number of matching files
-i|--ignore-case Ignore case
-l|--files-with-matches List only hash for each match
--once Stop searching after the first match
-s|--no-messages Suppress error messages about nonexistant
or unreadable files
-v|--invert-match Invert the sense of matching. Show only
files that have no matches. Implies -l
--verbose Show each file as it is analyzed