mirror of
https://github.com/git/git
synced 2024-08-25 02:35:46 +00:00
![Jeff King](/assets/img/avatar_default.png)
There are no more callers, and it's a rather confusing interface. This could just be folded into git_config_with_options(), but for the sake of readability, we'll leave it as a separate (static) helper function. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
318 lines
12 KiB
Plaintext
318 lines
12 KiB
Plaintext
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`.
|
|
|
|
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`.
|
|
|
|
Querying For Specific Variables
|
|
-------------------------------
|
|
|
|
For programs wanting to query for specific variables in a non-callback
|
|
manner, the config API provides two functions `git_config_get_value`
|
|
and `git_config_get_value_multi`. They both read values from an internal
|
|
cache generated previously from reading the config files.
|
|
|
|
`int git_config_get_value(const char *key, const char **value)`::
|
|
|
|
Finds the highest-priority value for the configuration variable `key`,
|
|
stores the pointer to it in `value` and returns 0. When the
|
|
configuration variable `key` is not found, returns 1 without touching
|
|
`value`. The caller should not free or modify `value`, as it is owned
|
|
by the cache.
|
|
|
|
`const struct string_list *git_config_get_value_multi(const char *key)`::
|
|
|
|
Finds and returns the value list, sorted in order of increasing priority
|
|
for the configuration variable `key`. When the configuration variable
|
|
`key` is not found, returns NULL. The caller should not free or modify
|
|
the returned pointer, as it is owned by the cache.
|
|
|
|
`void git_config_clear(void)`::
|
|
|
|
Resets and invalidates the config cache.
|
|
|
|
The config API also provides type specific API functions which do conversion
|
|
as well as retrieval for the queried variable, including:
|
|
|
|
`int git_config_get_int(const char *key, int *dest)`::
|
|
|
|
Finds and parses the value to an integer for the configuration variable
|
|
`key`. Dies on error; otherwise, stores the value of the parsed integer in
|
|
`dest` and returns 0. When the configuration variable `key` is not found,
|
|
returns 1 without touching `dest`.
|
|
|
|
`int git_config_get_ulong(const char *key, unsigned long *dest)`::
|
|
|
|
Similar to `git_config_get_int` but for unsigned longs.
|
|
|
|
`int git_config_get_bool(const char *key, int *dest)`::
|
|
|
|
Finds and parses the value into a boolean value, for the configuration
|
|
variable `key` 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,
|
|
stores the value of the parsed result in `dest` and returns 0. When the
|
|
configuration variable `key` is not found, returns 1 without touching
|
|
`dest`.
|
|
|
|
`int git_config_get_bool_or_int(const char *key, int *is_bool, int *dest)`::
|
|
|
|
Similar to `git_config_get_bool`, except that integers are copied as-is,
|
|
and `is_bool` flag is unset.
|
|
|
|
`int git_config_get_maybe_bool(const char *key, int *dest)`::
|
|
|
|
Similar to `git_config_get_bool`, except that it returns -1 on error
|
|
rather than dying.
|
|
|
|
`int git_config_get_string_const(const char *key, const char **dest)`::
|
|
|
|
Allocates and copies the retrieved string into the `dest` parameter for
|
|
the configuration variable `key`; if NULL string is given, prints an
|
|
error message and returns -1. When the configuration variable `key` is
|
|
not found, returns 1 without touching `dest`.
|
|
|
|
`int git_config_get_string(const char *key, char **dest)`::
|
|
|
|
Similar to `git_config_get_string_const`, except that retrieved value
|
|
copied into the `dest` parameter is a mutable string.
|
|
|
|
`int git_config_get_pathname(const char *key, const char **dest)`::
|
|
|
|
Similar to `git_config_get_string`, but expands `~` or `~user` into
|
|
the user's home directory when found at the beginning of the path.
|
|
|
|
`git_die_config(const char *key, const char *err, ...)`::
|
|
|
|
First prints the error message specified by the caller in `err` and then
|
|
dies printing the line number and the file name of the highest priority
|
|
value for the configuration variable `key`.
|
|
|
|
`void git_die_config_linenr(const char *key, const char *filename, int linenr)`::
|
|
|
|
Helper function which formats the die error message according to the
|
|
parameters entered. Used by `git_die_config()`. It can be used by callers
|
|
handling `git_config_get_value_multi()` to print the correct error message
|
|
for the desired value.
|
|
|
|
See test-config.c for usage examples.
|
|
|
|
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.
|
|
|
|
Custom Configsets
|
|
-----------------
|
|
|
|
A `config_set` can be used to construct an in-memory cache for
|
|
config-like files that the caller specifies (i.e., files like `.gitmodules`,
|
|
`~/.gitconfig` etc.). For example,
|
|
|
|
---------------------------------------
|
|
struct config_set gm_config;
|
|
git_configset_init(&gm_config);
|
|
int b;
|
|
/* we add config files to the config_set */
|
|
git_configset_add_file(&gm_config, ".gitmodules");
|
|
git_configset_add_file(&gm_config, ".gitmodules_alt");
|
|
|
|
if (!git_configset_get_bool(gm_config, "submodule.frotz.ignore", &b)) {
|
|
/* hack hack hack */
|
|
}
|
|
|
|
/* when we are done with the configset */
|
|
git_configset_clear(&gm_config);
|
|
----------------------------------------
|
|
|
|
Configset API provides functions for the above mentioned work flow, including:
|
|
|
|
`void git_configset_init(struct config_set *cs)`::
|
|
|
|
Initializes the config_set `cs`.
|
|
|
|
`int git_configset_add_file(struct config_set *cs, const char *filename)`::
|
|
|
|
Parses the file and adds the variable-value pairs to the `config_set`,
|
|
dies if there is an error in parsing the file. Returns 0 on success, or
|
|
-1 if the file does not exist or is inaccessible. The user has to decide
|
|
if he wants to free the incomplete configset or continue using it when
|
|
the function returns -1.
|
|
|
|
`int git_configset_get_value(struct config_set *cs, const char *key, const char **value)`::
|
|
|
|
Finds the highest-priority value for the configuration variable `key`
|
|
and config set `cs`, stores the pointer to it in `value` and returns 0.
|
|
When the configuration variable `key` is not found, returns 1 without
|
|
touching `value`. The caller should not free or modify `value`, as it
|
|
is owned by the cache.
|
|
|
|
`const struct string_list *git_configset_get_value_multi(struct config_set *cs, const char *key)`::
|
|
|
|
Finds and returns the value list, sorted in order of increasing priority
|
|
for the configuration variable `key` and config set `cs`. When the
|
|
configuration variable `key` is not found, returns NULL. The caller
|
|
should not free or modify the returned pointer, as it is owned by the cache.
|
|
|
|
`void git_configset_clear(struct config_set *cs)`::
|
|
|
|
Clears `config_set` structure, removes all saved variable-value pairs.
|
|
|
|
In addition to above functions, the `config_set` API provides type specific
|
|
functions in the vein of `git_config_get_int` and family but with an extra
|
|
parameter, pointer to struct `config_set`.
|
|
They all behave similarly to the `git_config_get*()` family described in
|
|
"Querying For Specific Variables" above.
|
|
|
|
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.
|