Thank you for taking the time to respond to me. When I run the said shell command, this error reported: # git log -P --all-match --grep '12' --grep '\b(?!t123\b)\w+' fatal: unrecognized argument: -P The version of git which I am currently using is 2.7.4. One more question, could you please explain '\b(?!t123\b)\w+' in more detail for me? Or suggest some related documents for me to go through? Thank you for your help. Best regards. On Fri, Jul 10, 2020 at 4:14 PM Carlo Arenas <carenas@xxxxxxxxx> wrote: > > it is easier to write specific "not match" using PCRE syntax, but > there are several other options to choose from combining as many > expressions as needed from the `git log` man page: > > git log -P --all-match --grep '12' --grep '\b(?!t123\b)\w+' > > Carlo