1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
|
config API
==========
The config API gives callers a way to access Git configuration files
(and files which have the same syntax). See linkgit:git-config[1] for a
discussion of the config file syntax.
General Usage
-------------
Config files are parsed linearly, and each variable found is passed to a
caller-provided callback function. The callback function is responsible
for any actions to be taken on the config option, and is free to ignore
some options. It is not uncommon for the configuration to be parsed
several times during the run of a Git program, with different callbacks
picking out different variables useful to themselves.
A config callback function takes three parameters:
- the name of the parsed variable. This is in canonical "flat" form: the
section, subsection, and variable segments will be separated by dots,
and the section and variable segments will be all lowercase. E.g.,
`core.ignorecase`, `diff.SomeType.textconv`.
- the value of the found variable, as a string. If the variable had no
value specified, the value will be NULL (typically this means it
should be interpreted as boolean true).
- a void pointer passed in by the caller of the config API; this can
contain callback-specific data
A config callback should return 0 for success, or -1 if the variable
could not be parsed properly.
Basic Config Querying
---------------------
Most programs will simply want to look up variables in all config files
that Git knows about, using the normal precedence rules. To do this,
call `git_config` with a callback function and void data pointer.
`git_config` will read all config sources in order of increasing
priority. Thus a callback should typically overwrite previously-seen
entries with new ones (e.g., if both the user-wide `~/.gitconfig` and
repo-specific `.git/config` contain `color.ui`, the config machinery
will first feed the user-wide one to the callback, and then the
repo-specific one; by overwriting, the higher-priority repo-specific
value is left at the end).
The `git_config_with_options` function lets the caller examine config
while adjusting some of the default behavior of `git_config`. It should
almost never be used by "regular" Git code that is looking up
configuration variables. It is intended for advanced callers like
`git-config`, which are intentionally tweaking the normal config-lookup
process. It takes two extra parameters:
`filename`::
If this parameter is non-NULL, it specifies the name of a file to
parse for configuration, rather than looking in the usual files. Regular
`git_config` defaults to `NULL`.
`respect_includes`::
Specify whether include directives should be followed in parsed files.
Regular `git_config` defaults to `1`.
There is a special version of `git_config` called `git_config_early`.
This version takes an additional parameter to specify the repository
config, instead of having it looked up via `git_path`. This is useful
early in a Git program before the repository has been found. Unless
you're working with early setup code, you probably don't want to use
this.
Reading Specific Files
----------------------
To read a specific file in git-config format, use
`git_config_from_file`. This takes the same callback and data parameters
as `git_config`.
Value Parsing Helpers
---------------------
To aid in parsing string values, the config API provides callbacks with
a number of helper functions, including:
`git_config_int`::
Parse the string to an integer, including unit factors. Dies on error;
otherwise, returns the parsed result.
`git_config_ulong`::
Identical to `git_config_int`, but for unsigned longs.
`git_config_bool`::
Parse a string into a boolean value, respecting keywords like "true" and
"false". Integer values are converted into true/false values (when they
are non-zero or zero, respectively). Other values cause a die(). If
parsing is successful, the return value is the result.
`git_config_bool_or_int`::
Same as `git_config_bool`, except that integers are returned as-is, and
an `is_bool` flag is unset.
`git_config_maybe_bool`::
Same as `git_config_bool`, except that it returns -1 on error rather
than dying.
`git_config_string`::
Allocates and copies the value string into the `dest` parameter; if no
string is given, prints an error message and returns -1.
`git_config_pathname`::
Similar to `git_config_string`, but expands `~` or `~user` into the
user's home directory when found at the beginning of the path.
Include Directives
------------------
By default, the config parser does not respect include directives.
However, a caller can use the special `git_config_include` wrapper
callback to support them. To do so, you simply wrap your "real" callback
function and data pointer in a `struct config_include_data`, and pass
the wrapper to the regular config-reading functions. For example:
-------------------------------------------
int read_file_with_include(const char *file, config_fn_t fn, void *data)
{
struct config_include_data inc = CONFIG_INCLUDE_INIT;
inc.fn = fn;
inc.data = data;
return git_config_from_file(git_config_include, file, &inc);
}
-------------------------------------------
`git_config` respects includes automatically. The lower-level
`git_config_from_file` does not.
Writing Config Files
--------------------
Git gives multiple entry points in the Config API to write config values to
files namely `git_config_set_in_file` and `git_config_set`, which write to
a specific config file or to `.git/config` respectively. They both take a
key/value pair as parameter.
In the end they both call `git_config_set_multivar_in_file` which takes four
parameters:
- the name of the file, as a string, to which key/value pairs will be written.
- the name of key, as a string. This is in canonical "flat" form: the section,
subsection, and variable segments will be separated by dots, and the section
and variable segments will be all lowercase.
E.g., `core.ignorecase`, `diff.SomeType.textconv`.
- the value of the variable, as a string. If value is equal to NULL, it will
remove the matching key from the config file.
- the value regex, as a string. It will disregard key/value pairs where value
does not match.
- a multi_replace value, as an int. If value is equal to zero, nothing or only
one matching key/value is replaced, else all matching key/values (regardless
how many) are removed, before the new pair is written.
It returns 0 on success.
Also, there are functions `git_config_rename_section` and
`git_config_rename_section_in_file` with parameters `old_name` and `new_name`
for renaming or removing sections in the config files. If NULL is passed
through `new_name` parameter, the section will be removed from the config file.
|
