1ref iteration API 2================= 3 4 5Iteration of refs is done by using an iterate function which will call a 6callback function for every ref. The callback function has this 7signature: 8 9 int handle_one_ref(const char *refname, const unsigned char *sha1, 10 int flags, void *cb_data); 11 12There are different kinds of iterate functions which all take a 13callback of this type. The callback is then called for each found ref 14until the callback returns nonzero. The returned value is then also 15returned by the iterate function. 16 17Iteration functions 18------------------- 19 20* `head_ref()` just iterates the head ref. 21 22* `for_each_ref()` iterates all refs. 23 24* `for_each_ref_in()` iterates all refs which have a defined prefix and 25 strips that prefix from the passed variable refname. 26 27* `for_each_tag_ref()`, `for_each_branch_ref()`, `for_each_remote_ref()`, 28 `for_each_replace_ref()` iterate refs from the respective area. 29 30* `for_each_glob_ref()` iterates all refs that match the specified glob 31 pattern. 32 33* `for_each_glob_ref_in()` the previous and `for_each_ref_in()` combined. 34 35* `head_ref_submodule()`, `for_each_ref_submodule()`, 36 `for_each_ref_in_submodule()`, `for_each_tag_ref_submodule()`, 37 `for_each_branch_ref_submodule()`, `for_each_remote_ref_submodule()` 38 do the same as the functions described above but for a specified 39 submodule. 40 41* `for_each_rawref()` can be used to learn about broken ref and symref. 42 43* `for_each_reflog()` iterates each reflog file. 44 45Submodules 46---------- 47 48If you want to iterate the refs of a submodule you first need to add the 49submodules object database. You can do this by a code-snippet like 50this: 51 52 const char *path = "path/to/submodule" 53 if (!add_submodule_odb(path)) 54 die("Error submodule '%s' not populated.", path); 55 56`add_submodule_odb()` will return an non-zero value on success. If you 57do not do this you will get an error for each ref that it does not point 58to a valid object. 59 60Note: As a side-effect of this you can not safely assume that all 61objects you lookup are available in superproject. All submodule objects 62will be available the same way as the superprojects objects. 63 64Example: 65-------- 66 67---- 68static int handle_remote_ref(const char *refname, 69 const unsigned char *sha1, int flags, void *cb_data) 70{ 71 struct strbuf *output = cb_data; 72 strbuf_addf(output, "%s\n", refname); 73 return 0; 74} 75 76... 77 78 struct strbuf output = STRBUF_INIT; 79 for_each_remote_ref(handle_remote_ref, &output); 80 printf("%s", output.buf); 81----