git

1
#!/bin/sh
2

3
# An example hook script to update a checked-out tree on a git push.
4
#
5
# This hook is invoked by git-receive-pack(1) when it reacts to git
6
# push and updates reference(s) in its repository, and when the push
7
# tries to update the branch that is currently checked out and the
8
# receive.denyCurrentBranch configuration variable is set to
9
# updateInstead.
10
#
11
# By default, such a push is refused if the working tree and the index
12
# of the remote repository has any difference from the currently
13
# checked out commit; when both the working tree and the index match
14
# the current commit, they are updated to match the newly pushed tip
15
# of the branch. This hook is to be used to override the default
16
# behaviour; however the code below reimplements the default behaviour
17
# as a starting point for convenient modification.
18
#
19
# The hook receives the commit with which the tip of the current
20
# branch is going to be updated:
21
commit=$1
22

23
# It can exit with a non-zero status to refuse the push (when it does
24
# so, it must not modify the index or the working tree).
25
die () {
26
	echo >&2 "$*"
27
	exit 1
28
}
29

30
# Or it can make any necessary changes to the working tree and to the
31
# index to bring them to the desired state when the tip of the current
32
# branch is updated to the new commit, and exit with a zero status.
33
#
34
# For example, the hook can simply run git read-tree -u -m HEAD "$1"
35
# in order to emulate git fetch that is run in the reverse direction
36
# with git push, as the two-tree form of git read-tree -u -m is
37
# essentially the same as git switch or git checkout that switches
38
# branches while keeping the local changes in the working tree that do
39
# not interfere with the difference between the branches.
40

41
# The below is a more-or-less exact translation to shell of the C code
42
# for the default behaviour for git's push-to-checkout hook defined in
43
# the push_to_deploy() function in builtin/receive-pack.c.
44
#
45
# Note that the hook will be executed from the repository directory,
46
# not from the working tree, so if you want to perform operations on
47
# the working tree, you will have to adapt your code accordingly, e.g.
48
# by adding "cd .." or using relative paths.
49

50
if ! git update-index -q --ignore-submodules --refresh
51
then
52
	die "Up-to-date check failed"
53
fi
54

55
if ! git diff-files --quiet --ignore-submodules --
56
then
57
	die "Working directory has unstaged changes"
58
fi
59

60
# This is a rough translation of:
61
#
62
#   head_has_history() ? "HEAD" : EMPTY_TREE_SHA1_HEX
63
if git cat-file -e HEAD 2>/dev/null
64
then
65
	head=HEAD
66
else
67
	head=$(git hash-object -t tree --stdin </dev/null)
68
fi
69

70
if ! git diff-index --quiet --cached --ignore-submodules $head --
71
then
72
	die "Working directory has staged changes"
73
fi
74

75
if ! git read-tree -u -m "$commit"
76
then
77
	die "Could not update working tree to new HEAD"
78
fi
79