Hello,
Whilst I have found answers to my question on the Web, only one seems to do exactly what I want ....
x---Y---y---y---y HEAD
/
...--o---o---C---o---S
\
n---n---N---*---* otherIn a script, how can I determine commit Y is reachable from the current HEAD ? And, much more importantly for my purposes, that commit N is _not_-reachable from the current HEAD ? "A is reachable from B" meaning B is an ancestor of A (B could possibly part of a merge (not shown in the above diagram)):
✓ Commits o(all), C, S, x, y(all), and Y: YES (reachable). ✗ Commits n(all), N, and *(all): NO (not-reachable).
The only readily script-able answer I've found is to use `git branch --contains=Y' and check to see if the current branch (conveniently marked `*') is/isn't included in the output. That is probably Ok, but I'm wondering if there is some "better" method (with the IMPORTANT caveat it must work with GIT 1.5.x or later ;-\ ).
git-rev-list(1) may be a answer (see script below), but .... `git rev-list ^Y HEAD' lists all the y commits, which is Ok (correct for my purposes). However, `git rev-list ^N HEAD' lists commits x, Y, and y(all) on branch "other", which is not-Ok: As per above, the answer I want is "NO".
Apologies if I've overlooked something totally obvious !
cheers, -blf-
=====(cut here and below)=====reach02.sh===== #!/bin/bash # # x---Y---y---y---y HEAD # / # ...--o---o---C---o---S # \ # n---n---N---*---* other #
: ${GIT:=git} # Allow use of different installed GIT versions.update_file() {
date +"%c: $*" >>file
$GIT add file && $GIT commit -m "$*" file
}set -e # Terminate if problem creating diagrammed situation.
rm -rf -- reachable mkdir -- reachable cd reachable
$GIT version $GIT init
update_file o1 update_file o2 update_file "C (o3)"; $GIT tag C update_file o4 update_file "S (o5)"; $GIT tag S
$GIT checkout -b other update_file n1 update_file n2 update_file "N (n3)"; $GIT tag N update_file "*1" update_file "*2"
$GIT checkout master update_file x update_file "Y (y1)"; $GIT tag Y update_file y2 update_file y3 update_file y4
declare -i wrong=0
echo "Is Y reachable from HEAD? Wanted answer: Yes." $GIT log --oneline ^Y HEAD if $GIT rev-list --quiet ^Y HEAD; then echo "rev-list: YES (wanted answer)!" else echo "rev-list: No! *** not-wanted, oops... ***" wrong=$(( wrong + 1 )) fi if $GIT branch --contains=Y | grep -q -e '^\*'; then echo "contains: YES (wanted answer)!" else echo "contains: No! *** not-wanted, oops... ***" wrong=$(( wrong + 1 )) fi
echo "Is N reachable from HEAD? Wanted answer: No." $GIT log --oneline ^N HEAD if $GIT rev-list --quiet ^N HEAD; then echo "rev-list: YES? *** not-wanted, oops... ***" wrong=$(( wrong + 1 )) else echo "rev-list: No (wanted answer)!" fi if $GIT branch --contains=N | grep -q -e '^\*'; then echo "contains: YES? *** not-wanted, oops... ***" wrong=$(( wrong + 1 )) else echo "contains: No (wanted answer)!" fi
exit $wrong =====(cut here and above)=====reach02.sh=====
-- Brian Foster Principal MTS, Software | La Ciotat, France Maxim Integrated Products | Web: http://www.maxim-ic.com/
