[PATCH] Improve "git grep" flags handling

This allows any arbitrary flags to "grep", and knows about the few
special grep flags that take an argument too.

It also allows some flags for git-ls-files, although their usefulness
is questionable.

With this, something line

	git grep -w -1 pattern

works, without the script enumerating every possible flag.

[jc: this was the version after I showed Linus a barf-o-meter test
 version that avoids shell arrays.  The emperor penguin must have
 typed this version blindly, since he said:

    I'm not barfing, but that's probably because my brain just shut
    down and is desperately trying to gouge my eyes out with a spoon.

 I slightly fixed it to catch the remaining arguments meant to be
 given git-ls-files.]

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <redacted>

---

    Linus Torvalds [off-list ref] writes:

    Wouldn't it be _much_ nicer to just do which does use bash
    array variables, but dang, it does so for a reason: they
    really are very very useful, and they make it _so_ much more
    pleasant to do these things..

 Thanks, Linus.  This is what will go into "master" tonight.

 git-grep.sh |   64 ++++++++++++++++++++++++++++++++++++++---------------------
 1 files changed, 41 insertions(+), 23 deletions(-)

6df4eef9b10c8de2b9bc3dc769f3a008a1200df7

diff --git a/git-grep.sh b/git-grep.sh
--- a/git-grep.sh
+++ b/git-grep.sh

@@ -1,25 +1,43 @@
 #!/bin/sh
-flags=
-while :; do
-  pattern="$1"
-  case "$pattern" in
-  -i|-I|-a|-E|-H|-h|-l)
-    flags="$flags $pattern"
-    shift
-    ;;
-  -e)
-    pattern="$2"
-    shift
-    break
-    ;;
-  -*)
-    echo "unknown flag $pattern" >&2
-    exit 1
-    ;;
-  *)
-    break
-    ;;
-  esac
+#
+# Copyright (c) Linus Torvalds, 2005
+#
+
+pattern=
+flags=()
+git_flags=()
+while : ; do
+	case "$1" in
+	--cached|--deleted|--others|--killed|\
+	--ignored|--exclude=*|\
+	--exclude-from=*|\--exclude-per-directory=*)
+		git_flags=("${git_flags[@]}" "$1")
+		;;
+	-e)
+		pattern="$2"
+		shift
+		;;
+	-A|-B|-C|-D|-d|-f|-m)
+		flags=("${flags[@]}" "$1" "$2")
+		shift
+		;;
+	--)
+		# The rest are git-ls-files paths (or flags)
+		shift
+		break
+		;;
+	-*)
+		flags=("${flags[@]}" "$1")
+		;;
+	*)
+		if [ -z "$pattern" ]; then
+			pattern="$1"
+			shift
+		fi
+		break
+		;;
+	esac
+	shift
 done
-shift
-git-ls-files -z "$@" | xargs -0 grep $flags -e "$pattern"
+git-ls-files -z "${git_flags[@]}" "$@" |
+	xargs -0 grep "${flags[@]}" "$pattern"