mergetools/p4merge: create a base if none available
[git/git.git] / Documentation / git-sh-setup.txt
1 git-sh-setup(1)
2 ===============
3
4 NAME
5 ----
6 git-sh-setup - Common Git shell script setup code
7
8 SYNOPSIS
9 --------
10 [verse]
11 '. "$(git --exec-path)/git-sh-setup"'
12
13 DESCRIPTION
14 -----------
15
16 This is not a command the end user would want to run. Ever.
17 This documentation is meant for people who are studying the
18 Porcelain-ish scripts and/or are writing new ones.
19
20 The 'git sh-setup' scriptlet is designed to be sourced (using
21 `.`) by other shell scripts to set up some variables pointing at
22 the normal Git directories and a few helper shell functions.
23
24 Before sourcing it, your script should set up a few variables;
25 `USAGE` (and `LONG_USAGE`, if any) is used to define message
26 given by `usage()` shell function. `SUBDIRECTORY_OK` can be set
27 if the script can run from a subdirectory of the working tree
28 (some commands do not).
29
30 The scriptlet sets `GIT_DIR` and `GIT_OBJECT_DIRECTORY` shell
31 variables, but does *not* export them to the environment.
32
33 FUNCTIONS
34 ---------
35
36 die::
37 exit after emitting the supplied error message to the
38 standard error stream.
39
40 usage::
41 die with the usage message.
42
43 set_reflog_action::
44 set the message that will be recorded to describe the
45 end-user action in the reflog, when the script updates a
46 ref.
47
48 git_editor::
49 runs an editor of user's choice (GIT_EDITOR, core.editor, VISUAL or
50 EDITOR) on a given file, but error out if no editor is specified
51 and the terminal is dumb.
52
53 is_bare_repository::
54 outputs `true` or `false` to the standard output stream
55 to indicate if the repository is a bare repository
56 (i.e. without an associated working tree).
57
58 cd_to_toplevel::
59 runs chdir to the toplevel of the working tree.
60
61 require_work_tree::
62 checks if the current directory is within the working tree
63 of the repository, and otherwise dies.
64
65 require_work_tree_exists::
66 checks if the working tree associated with the repository
67 exists, and otherwise dies. Often done before calling
68 cd_to_toplevel, which is impossible to do if there is no
69 working tree.
70
71 require_clean_work_tree <action> [<hint>]::
72 checks that the working tree and index associated with the
73 repository have no uncommitted changes to tracked files.
74 Otherwise it emits an error message of the form `Cannot
75 <action>: <reason>. <hint>`, and dies. Example:
76 +
77 ----------------
78 require_clean_work_tree rebase "Please commit or stash them."
79 ----------------
80
81 get_author_ident_from_commit::
82 outputs code for use with eval to set the GIT_AUTHOR_NAME,
83 GIT_AUTHOR_EMAIL and GIT_AUTHOR_DATE variables for a given commit.
84
85 create_virtual_base::
86 modifies the first file so only lines in common with the
87 second file remain. If there is insufficient common material,
88 then the first file is left empty. The result is suitable
89 as a virtual base input for a 3-way merge.
90
91 GIT
92 ---
93 Part of the linkgit:git[1] suite