210 grep [options] pattern [files]::

   211     Search revisions of files for a regular expression.

   212 

   213     This command behaves differently than Unix grep.  It only accepts

   214     Python/Perl regexps.  It searches repository history, not the

   215     working directory.  It always prints the revision number in which

   216     a match appears.

   217 

   218     By default, grep only prints output for the first revision of a

   219     file in which it finds a match.  To get it to print every revision

   220     that contains a change in match status ("-" for a match that

   221     becomes a non-match, or "+" for a non-match that becomes a match),

   222     use the --every-match flag.

   223 

   224     options:

   225     -0, --print0              end fields with NUL

   226     -I, --include <pat>       include names matching the given patterns

   227     -X, --exclude <pat>       exclude names matching the given patterns

   228     -e, --every-match         print every revision that matches

   229     -i, --ignore-case         ignore case when matching

   230     -l, --files-with-matches  print only file names and revs that match

   231     -n, --line-number         print matching line numbers

   232     -r <rev>, --rev <rev>     search in given revision range

   233     -u, --user                print user who committed change

   234