Re: [PATCH] RFC Allow case insensitive search flag with git-grep for fixed-strings

Jeff King [off-list ref] writes:

On Fri, Nov 06, 2009 at 02:00:11AM -0800, Junio C Hamano wrote:

quoted

But I didn't try hard to find out what _else_ we are depending on.

It is not really _us_ depending on it. It is "things the user wants to
do that _we_ support, but that their grep might not." So I don't think
there is much point in enumerating features. If their system grep
doesn't handle options that they want to use, then it won't work for
them. If they don't use them, then they will be fine.

Though "-e" might be the exception, as I think we might use it
unconditionally. But something like "-F -i" really depends on whether
the user wants to use it.

Yes and no.

Even though we currently punt on a few platforms for simplicity and build
with NO_EXTERNAL_GREP, we could check if the set of options given are
within the feature set of what the platform's grep understands and choose
to spawn "grep" unless some options that are unsupported are used, in
which case we fall back to the internal one.

We could certainly do something like this if it turns out to be a problem.
An invocation that does not use -F and -i together can still spawn
external grep if that is faster.

You are correct about "-e".  Our NO_EXTERNAL_GREP on SunOS cannot be
avoided.

 builtin-grep.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/builtin-grep.c b/builtin-grep.c
index 1df25b0..2905f64 100644
--- a/builtin-grep.c
+++ b/builtin-grep.c

@@ -357,6 +357,9 @@ static int external_grep(struct grep_opt *opt, const char **paths, int cached)
 
 	if (opt->extended || (opt->relative && opt->prefix_length))
 		return -1;
+	if (NO_GREP_FIXED_IGNORE_CASE &&
+	    opt->fixed && (opt->regflags & REG_ICASE))
+		return -1;
 	len = nr = 0;
 	push_arg("grep");
 	if (opt->fixed)