Usage message clean-up, take #2

There were some problems with the usage message clean-up patch
series. I hadn't realised that subdirectory aware scripts can't source
git-sh-setup. I propose that we change this and let the scripts which
are subdirectory aware set a variable, SUBDIRECTORY_OK, before they
source git-sh-setup.

The scripts will also set USAGE and possibly LONG_USAGE before they
source git-sh-setup. If LONG_USAGE isn't set it defaults to USAGE.

If we go this way it's easy to catch --help in git-sh-setup, print the
(long) usage message to stdout and exit cleanly. git-sh-setup can
define a 'usage' shell function which can be called by the scripts to
print the short usage string to stderr and exit non-cleanly. It will
also be easy to change $0 to basename $0 or something else, if would
like to do that sometime in the future.

What follows is a patch to convert a couple of the commands to this
style. If it's ok with everyone to do it this way I will convert the
rest of the scripts too.

[jc: thrown in to proposed updates queue for comments.]

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 11 insertions, 13 deletions

diff --git a/git-bisect.sh b/git-bisect.sh
index 05dae8ad13..51e1e4417d 100755
--- a/git-bisect.sh
+++ b/git-bisect.sh
@@ -1,4 +1,15 @@
 #!/bin/sh
+
+USAGE='[start|bad|good|next|reset|visualize]'
+LONG_USAGE='git bisect start [<pathspec>]	reset bisect state and start bisection.
+git bisect bad [<rev>]		mark <rev> a known-bad revision.
+git bisect good [<rev>...]	mark <rev>... known-good revisions.
+git bisect next			find next bisection to test and check it out.
+git bisect reset [<branch>]	finish bisection search and go back to branch.
+git bisect visualize            show bisect status in gitk.
+git bisect replay <logfile>	replay bisection log
+git bisect log			show bisect log.'
+
 . git-sh-setup
 
 sq() {
@@ -11,19 +22,6 @@ sq() {
 	' "$@"
 }
 
-usage() {
-    echo >&2 'usage: git bisect [start|bad|good|next|reset|visualize]
-git bisect start [<pathspec>]	reset bisect state and start bisection.
-git bisect bad [<rev>]		mark <rev> a known-bad revision.
-git bisect good [<rev>...]	mark <rev>... known-good revisions.
-git bisect next			find next bisection to test and check it out.
-git bisect reset [<branch>]	finish bisection search and go back to branch.
-git bisect visualize            show bisect status in gitk.
-git bisect replay <logfile>	replay bisection log
-git bisect log			show bisect log.'
-    exit 1
-}
-
 bisect_autostart() {
 	test -d "$GIT_DIR/refs/bisect" || {
 		echo >&2 'You need to start by "git bisect start"'