hg grep [OPTION]... PATTERN [FILE]...

search for a pattern in specified files and revisions

    Search revisions of files for a regular expression.

    This command behaves differently than Unix grep. It only accepts
    Python/Perl regexps. It searches repository history, not the working
    directory. It always prints the revision number in which a match appears.

    By default, grep only prints output for the first revision of a file in
    which it finds a match. To get it to print every revision that contains a
    change in match status ("-" for a match that becomes a non-match, or "+"
    for a non-match that becomes a match), use the --all flag.

    Returns 0 if a match is found, 1 otherwise.

options:

 -0 --print0               end fields with NUL
    --all                  print all revisions that match
 -f --follow               follow changeset history, or file history across
                           copies and renames
 -i --ignore-case          ignore case when matching
 -l --files-with-matches   print only filenames and revisions that match
 -n --line-number          print matching line numbers
 -r --rev REV [+]          only search files changed within revision range
 -u --user                 list the author (long with -v)
 -d --date                 list the date (short with -q)
 -I --include PATTERN [+]  include names matching the given patterns
 -X --exclude PATTERN [+]  exclude names matching the given patterns

[+] marked option can be specified multiple times

use "hg -v help grep" to show global options