config: avoid a funny sentinel value "a^"
[git] / git-difftool--helper.sh
1 #!/bin/sh
2 # git-difftool--helper is a GIT_EXTERNAL_DIFF-compatible diff tool launcher.
3 # This script is typically launched by using the 'git difftool'
4 # convenience command.
5 #
6 # Copyright (c) 2009, 2010 David Aguilar
7
8 TOOL_MODE=diff
9 . git-mergetool--lib
10
11 # difftool.prompt controls the default prompt/no-prompt behavior
12 # and is overridden with $GIT_DIFFTOOL*_PROMPT.
13 should_prompt () {
14         prompt_merge=$(git config --bool mergetool.prompt || echo true)
15         prompt=$(git config --bool difftool.prompt || echo $prompt_merge)
16         if test "$prompt" = true
17         then
18                 test -z "$GIT_DIFFTOOL_NO_PROMPT"
19         else
20                 test -n "$GIT_DIFFTOOL_PROMPT"
21         fi
22 }
23
24 # Indicates that --extcmd=... was specified
25 use_ext_cmd () {
26         test -n "$GIT_DIFFTOOL_EXTCMD"
27 }
28
29 launch_merge_tool () {
30         # Merged is the filename as it appears in the work tree
31         # Local is the contents of a/filename
32         # Remote is the contents of b/filename
33         # Custom merge tool commands might use $BASE so we provide it
34         MERGED="$1"
35         LOCAL="$2"
36         REMOTE="$3"
37         BASE="$1"
38
39         # $LOCAL and $REMOTE are temporary files so prompt
40         # the user with the real $MERGED name before launching $merge_tool.
41         if should_prompt
42         then
43                 printf "\nViewing (%s/%s): '%s'\n" "$GIT_DIFF_PATH_COUNTER" \
44                         "$GIT_DIFF_PATH_TOTAL" "$MERGED"
45                 if use_ext_cmd
46                 then
47                         printf "Launch '%s' [Y/n]: " \
48                                 "$GIT_DIFFTOOL_EXTCMD"
49                 else
50                         printf "Launch '%s' [Y/n]: " "$merge_tool"
51                 fi
52                 if read ans && test "$ans" = n
53                 then
54                         return
55                 fi
56         fi
57
58         if use_ext_cmd
59         then
60                 export BASE
61                 eval $GIT_DIFFTOOL_EXTCMD '"$LOCAL"' '"$REMOTE"'
62         else
63                 run_merge_tool "$merge_tool"
64         fi
65 }
66
67 if ! use_ext_cmd
68 then
69         if test -n "$GIT_DIFF_TOOL"
70         then
71                 merge_tool="$GIT_DIFF_TOOL"
72         else
73                 merge_tool="$(get_merge_tool)" || exit
74         fi
75 fi
76
77 if test -n "$GIT_DIFFTOOL_DIRDIFF"
78 then
79         LOCAL="$1"
80         REMOTE="$2"
81         run_merge_tool "$merge_tool" false
82 else
83         # Launch the merge tool on each path provided by 'git diff'
84         while test $# -gt 6
85         do
86                 launch_merge_tool "$1" "$2" "$5"
87                 shift 7
88         done
89 fi