gitattributes mechanism gives a uniform way to associate various attributes to set of paths.
Data Structure
-
struct git_attr
-
An attribute is an opaque object that is identified by its name. Pass the name and its length to
git_attr()
function to obtain the object of this type. The internal representation of this structure is of no interest to the calling programs. -
struct git_attr_check
-
This structure represents a set of attributes to check in a call to
git_checkattr()
function, and receives the results.
Calling Sequence
-
Prepare an array of
struct git_attr_check
to define the list of attributes you would want to check. To populate this array, you would need to define necessary attributes by callinggit_attr()
function. -
Call git_checkattr() to check the attributes for the path.
-
Inspect
git_attr_check
structure to see how each of the attribute in the array is defined for the path.
Attribute Values
An attribute for a path can be in one of four states: Set, Unset,
Unspecified or set to a string, and .value
member of struct
git_attr_check
records it. There are three macros to check these:
-
ATTR_TRUE()
-
Returns true if the attribute is Set for the path.
-
ATTR_FALSE()
-
Returns true if the attribute is Unset for the path.
-
ATTR_UNSET()
-
Returns true if the attribute is Unspecified for the path.
If none of the above returns true, .value
member points at a string
value of the attribute for the path.
Example
To see how attributes "crlf" and "indent" are set for different paths.
-
Prepare an array of
struct git_attr_check
with two elements (because we are checking two attributes). Initialize theirattr
member with pointers tostruct git_attr
obtained by callinggit_attr()
:
static struct git_attr_check check[2];
static void setup_check(void)
{
if (check[0].attr)
return; /* already done */
check[0].attr = git_attr("crlf", 4);
check[1].attr = git_attr("ident", 5);
}
-
Call
git_checkattr()
with the prepared array ofstruct git_attr_check
:
const char *path;
setup_check();
git_checkattr(path, ARRAY_SIZE(check), check);
-
Act on
.value
member of the result, left incheck[]
:
const char *value = check[0].value;
if (ATTR_TRUE(value)) {
The attribute is Set, by listing only the name of the
attribute in the gitattributes file for the path.
} else if (ATTR_FALSE(value)) {
The attribute is Unset, by listing the name of the
attribute prefixed with a dash - for the path.
} else if (ATTR_UNSET(value)) {
The attribute is not set nor unset for the path.
} else if (!strcmp(value, "input")) {
If none of ATTR_TRUE(), ATTR_FALSE(), or ATTR_UNSET() is
true, the value is a string set in the gitattributes
file for the path by saying "attr=value".
} else if (... other check using value as string ...) {
...
}
(JC)