Adding upstream version 1.7.2+ds.upstream/1.7.2+ds

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 798 insertions, 0 deletions

diff --git a/examples/general.c b/examples/general.c
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+/*
+ * libgit2 "general" example - shows basic libgit2 concepts
+ *
+ * Written by the libgit2 contributors
+ *
+ * To the extent possible under law, the author(s) have dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ *
+ * You should have received a copy of the CC0 Public Domain Dedication along
+ * with this software. If not, see
+ * <http://creativecommons.org/publicdomain/zero/1.0/>.
+ */
+
+/**
+ * [**libgit2**][lg] is a portable, pure C implementation of the Git core
+ * methods provided as a re-entrant linkable library with a solid API,
+ * allowing you to write native speed custom Git applications in any
+ * language which supports C bindings.
+ *
+ * This file is an example of using that API in a real, compilable C file.
+ * As the API is updated, this file will be updated to demonstrate the new
+ * functionality.
+ *
+ * If you're trying to write something in C using [libgit2][lg], you should
+ * also check out the generated [API documentation][ap]. We try to link to
+ * the relevant sections of the API docs in each section in this file.
+ *
+ * **libgit2** (for the most part) only implements the core plumbing
+ * functions, not really the higher level porcelain stuff. For a primer on
+ * Git Internals that you will need to know to work with Git at this level,
+ * check out [Chapter 10][pg] of the Pro Git book.
+ *
+ * [lg]: http://libgit2.github.com
+ * [ap]: http://libgit2.github.com/libgit2
+ * [pg]: https://git-scm.com/book/en/v2/Git-Internals-Plumbing-and-Porcelain
+ */
+
+#include "common.h"
+
+/**
+ * ### Includes
+ *
+ * Including the `git2.h` header will include all the other libgit2 headers
+ * that you need.  It should be the only thing you need to include in order
+ * to compile properly and get all the libgit2 API.
+ */
+#include "git2.h"
+
+static void oid_parsing(git_oid *out);
+static void object_database(git_repository *repo, git_oid *oid);
+static void commit_writing(git_repository *repo);
+static void commit_parsing(git_repository *repo);
+static void tag_parsing(git_repository *repo);
+static void tree_parsing(git_repository *repo);
+static void blob_parsing(git_repository *repo);
+static void revwalking(git_repository *repo);
+static void index_walking(git_repository *repo);
+static void reference_listing(git_repository *repo);
+static void config_files(const char *repo_path, git_repository *repo);
+
+/**
+ * Almost all libgit2 functions return 0 on success or negative on error.
+ * This is not production quality error checking, but should be sufficient
+ * as an example.
+ */
+static void check_error(int error_code, const char *action)
+{
+	const git_error *error = git_error_last();
+	if (!error_code)
+		return;
+
+	printf("Error %d %s - %s\n", error_code, action,
+			(error && error->message) ? error->message : "???");
+
+	exit(1);
+}
+
+int lg2_general(git_repository *repo, int argc, char** argv)
+{
+	int error;
+	git_oid oid;
+	char *repo_path;
+
+	/**
+	 * Initialize the library, this will set up any global state which libgit2 needs
+	 * including threading and crypto
+	 */
+	git_libgit2_init();
+
+	/**
+	 * ### Opening the Repository
+	 *
+	 * There are a couple of methods for opening a repository, this being the
+	 * simplest.  There are also [methods][me] for specifying the index file
+	 * and work tree locations, here we assume they are in the normal places.
+	 *
+	 * (Try running this program against tests/resources/testrepo.git.)
+	 *
+	 * [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository
+	 */
+	repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git";
+
+	error = git_repository_open(&repo, repo_path);
+	check_error(error, "opening repository");
+
+	oid_parsing(&oid);
+	object_database(repo, &oid);
+	commit_writing(repo);
+	commit_parsing(repo);
+	tag_parsing(repo);
+	tree_parsing(repo);
+	blob_parsing(repo);
+	revwalking(repo);
+	index_walking(repo);
+	reference_listing(repo);
+	config_files(repo_path, repo);
+
+	/**
+	 * Finally, when you're done with the repository, you can free it as well.
+	 */
+	git_repository_free(repo);
+
+	return 0;
+}
+
+/**
+ * ### SHA-1 Value Conversions
+ */
+static void oid_parsing(git_oid *oid)
+{
+	char out[GIT_OID_SHA1_HEXSIZE+1];
+	char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045";
+
+	printf("*Hex to Raw*\n");
+
+	/**
+	 * For our first example, we will convert a 40 character hex value to the
+	 * 20 byte raw SHA1 value.
+	 *
+	 * The `git_oid` is the structure that keeps the SHA value. We will use
+	 * this throughout the example for storing the value of the current SHA
+	 * key we're working with.
+	 */
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(oid, hex, GIT_OID_SHA1);
+#else
+	git_oid_fromstr(oid, hex);
+#endif
+
+	/*
+	 * Once we've converted the string into the oid value, we can get the raw
+	 * value of the SHA by accessing `oid.id`
+	 *
+	 * Next we will convert the 20 byte raw SHA1 value to a human readable 40
+	 * char hex value.
+	 */
+	printf("\n*Raw to Hex*\n");
+	out[GIT_OID_SHA1_HEXSIZE] = '\0';
+
+	/**
+	 * If you have a oid, you can easily get the hex value of the SHA as well.
+	 */
+	git_oid_fmt(out, oid);
+	printf("SHA hex string: %s\n", out);
+}
+
+/**
+ * ### Working with the Object Database
+ *
+ * **libgit2** provides [direct access][odb] to the object database.  The
+ * object database is where the actual objects are stored in Git. For
+ * working with raw objects, we'll need to get this structure from the
+ * repository.
+ *
+ * [odb]: http://libgit2.github.com/libgit2/#HEAD/group/odb
+ */
+static void object_database(git_repository *repo, git_oid *oid)
+{
+	char oid_hex[GIT_OID_SHA1_HEXSIZE+1] = { 0 };
+	const unsigned char *data;
+	const char *str_type;
+	int error;
+	git_odb_object *obj;
+	git_odb *odb;
+	git_object_t otype;
+
+	git_repository_odb(&odb, repo);
+
+	/**
+	 * #### Raw Object Reading
+	 */
+
+	printf("\n*Raw Object Read*\n");
+
+	/**
+	 * We can read raw objects directly from the object database if we have
+	 * the oid (SHA) of the object.  This allows us to access objects without
+	 * knowing their type and inspect the raw bytes unparsed.
+	 */
+	error = git_odb_read(&obj, odb, oid);
+	check_error(error, "finding object in repository");
+
+	/**
+	 * A raw object only has three properties - the type (commit, blob, tree
+	 * or tag), the size of the raw data and the raw, unparsed data itself.
+	 * For a commit or tag, that raw data is human readable plain ASCII
+	 * text. For a blob it is just file contents, so it could be text or
+	 * binary data. For a tree it is a special binary format, so it's unlikely
+	 * to be hugely helpful as a raw object.
+	 */
+	data = (const unsigned char *)git_odb_object_data(obj);
+	otype = git_odb_object_type(obj);
+
+	/**
+	 * We provide methods to convert from the object type which is an enum, to
+	 * a string representation of that value (and vice-versa).
+	 */
+	str_type = git_object_type2string(otype);
+	printf("object length and type: %d, %s\nobject data: %s\n",
+			(int)git_odb_object_size(obj),
+			str_type, data);
+
+	/**
+	 * For proper memory management, close the object when you are done with
+	 * it or it will leak memory.
+	 */
+	git_odb_object_free(obj);
+
+	/**
+	 * #### Raw Object Writing
+	 */
+
+	printf("\n*Raw Object Write*\n");
+
+	/**
+	 * You can also write raw object data to Git. This is pretty cool because
+	 * it gives you direct access to the key/value properties of Git.  Here
+	 * we'll write a new blob object that just contains a simple string.
+	 * Notice that we have to specify the object type as the `git_otype` enum.
+	 */
+	git_odb_write(oid, odb, "test data", sizeof("test data") - 1, GIT_OBJECT_BLOB);
+
+	/**
+	 * Now that we've written the object, we can check out what SHA1 was
+	 * generated when the object was written to our database.
+	 */
+	git_oid_fmt(oid_hex, oid);
+	printf("Written Object: %s\n", oid_hex);
+
+	/**
+	 * Free the object database after usage.
+	 */
+	git_odb_free(odb);
+}
+
+/**
+ * #### Writing Commits
+ *
+ * libgit2 provides a couple of methods to create commit objects easily as
+ * well. There are four different create signatures, we'll just show one
+ * of them here.  You can read about the other ones in the [commit API
+ * docs][cd].
+ *
+ * [cd]: http://libgit2.github.com/libgit2/#HEAD/group/commit
+ */
+static void commit_writing(git_repository *repo)
+{
+	git_oid tree_id, parent_id, commit_id;
+	git_tree *tree;
+	git_commit *parent;
+	git_signature *author, *committer;
+	char oid_hex[GIT_OID_SHA1_HEXSIZE+1] = { 0 };
+
+	printf("\n*Commit Writing*\n");
+
+	/**
+	 * Creating signatures for an authoring identity and time is simple.  You
+	 * will need to do this to specify who created a commit and when.  Default
+	 * values for the name and email should be found in the `user.name` and
+	 * `user.email` configuration options.  See the `config` section of this
+	 * example file to see how to access config values.
+	 */
+	git_signature_new(&author,
+			"Scott Chacon", "schacon@gmail.com", 123456789, 60);
+	git_signature_new(&committer,
+			"Scott A Chacon", "scott@github.com", 987654321, 90);
+
+	/**
+	 * Commit objects need a tree to point to and optionally one or more
+	 * parents.  Here we're creating oid objects to create the commit with,
+	 * but you can also use
+	 */
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1", GIT_OID_SHA1);
+	git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644", GIT_OID_SHA1);
+#else
+	git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+	git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+#endif
+	git_tree_lookup(&tree, repo, &tree_id);
+	git_commit_lookup(&parent, repo, &parent_id);
+
+	/**
+	 * Here we actually create the commit object with a single call with all
+	 * the values we need to create the commit.  The SHA key is written to the
+	 * `commit_id` variable here.
+	 */
+	git_commit_create_v(
+			&commit_id, /* out id */
+			repo,
+			NULL, /* do not update the HEAD */
+			author,
+			committer,
+			NULL, /* use default message encoding */
+			"example commit",
+			tree,
+			1, parent);
+
+	/**
+	 * Now we can take a look at the commit SHA we've generated.
+	 */
+	git_oid_fmt(oid_hex, &commit_id);
+	printf("New Commit: %s\n", oid_hex);
+
+	/**
+	 * Free all objects used in the meanwhile.
+	 */
+	git_tree_free(tree);
+	git_commit_free(parent);
+	git_signature_free(author);
+	git_signature_free(committer);
+}
+
+/**
+ * ### Object Parsing
+ *
+ * libgit2 has methods to parse every object type in Git so you don't have
+ * to work directly with the raw data. This is much faster and simpler
+ * than trying to deal with the raw data yourself.
+ */
+
+/**
+ * #### Commit Parsing
+ *
+ * [Parsing commit objects][pco] is simple and gives you access to all the
+ * data in the commit - the author (name, email, datetime), committer
+ * (same), tree, message, encoding and parent(s).
+ *
+ * [pco]: http://libgit2.github.com/libgit2/#HEAD/group/commit
+ */
+static void commit_parsing(git_repository *repo)
+{
+	const git_signature *author, *cmtter;
+	git_commit *commit, *parent;
+	git_oid oid;
+	char oid_hex[GIT_OID_SHA1_HEXSIZE+1];
+	const char *message;
+	unsigned int parents, p;
+	int error;
+	time_t time;
+
+	printf("\n*Commit Parsing*\n");
+
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479", GIT_OID_SHA1);
+#else
+	git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479");
+#endif
+
+	error = git_commit_lookup(&commit, repo, &oid);
+	check_error(error, "looking up commit");
+
+	/**
+	 * Each of the properties of the commit object are accessible via methods,
+	 * including commonly needed variations, such as `git_commit_time` which
+	 * returns the author time and `git_commit_message` which gives you the
+	 * commit message (as a NUL-terminated string).
+	 */
+	message  = git_commit_message(commit);
+	author   = git_commit_author(commit);
+	cmtter   = git_commit_committer(commit);
+	time    = git_commit_time(commit);
+
+	/**
+	 * The author and committer methods return [git_signature] structures,
+	 * which give you name, email and `when`, which is a `git_time` structure,
+	 * giving you a timestamp and timezone offset.
+	 */
+	printf("Author: %s (%s)\nCommitter: %s (%s)\nDate: %s\nMessage: %s\n",
+		author->name, author->email,
+		cmtter->name, cmtter->email,
+		ctime(&time), message);
+
+	/**
+	 * Commits can have zero or more parents. The first (root) commit will
+	 * have no parents, most commits will have one (i.e. the commit it was
+	 * based on) and merge commits will have two or more.  Commits can
+	 * technically have any number, though it's rare to have more than two.
+	 */
+	parents  = git_commit_parentcount(commit);
+	for (p = 0;p < parents;p++) {
+		memset(oid_hex, 0, sizeof(oid_hex));
+
+		git_commit_parent(&parent, commit, p);
+		git_oid_fmt(oid_hex, git_commit_id(parent));
+		printf("Parent: %s\n", oid_hex);
+		git_commit_free(parent);
+	}
+
+	git_commit_free(commit);
+}
+
+/**
+ * #### Tag Parsing
+ *
+ * You can parse and create tags with the [tag management API][tm], which
+ * functions very similarly to the commit lookup, parsing and creation
+ * methods, since the objects themselves are very similar.
+ *
+ * [tm]: http://libgit2.github.com/libgit2/#HEAD/group/tag
+ */
+static void tag_parsing(git_repository *repo)
+{
+	git_commit *commit;
+	git_object_t type;
+	git_tag *tag;
+	git_oid oid;
+	const char *name, *message;
+	int error;
+
+	printf("\n*Tag Parsing*\n");
+
+	/**
+	 * We create an oid for the tag object if we know the SHA and look it up
+	 * the same way that we would a commit (or any other object).
+	 */
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1", GIT_OID_SHA1);
+#else
+	git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1");
+#endif
+
+	error = git_tag_lookup(&tag, repo, &oid);
+	check_error(error, "looking up tag");
+
+	/**
+	 * Now that we have the tag object, we can extract the information it
+	 * generally contains: the target (usually a commit object), the type of
+	 * the target object (usually 'commit'), the name ('v1.0'), the tagger (a
+	 * git_signature - name, email, timestamp), and the tag message.
+	 */
+	git_tag_target((git_object **)&commit, tag);
+	name = git_tag_name(tag);		/* "test" */
+	type = git_tag_target_type(tag);	/* GIT_OBJECT_COMMIT (object_t enum) */
+	message = git_tag_message(tag);		/* "tag message\n" */
+	printf("Tag Name: %s\nTag Type: %s\nTag Message: %s\n",
+		name, git_object_type2string(type), message);
+
+	/**
+	 * Free both the commit and tag after usage.
+	 */
+	git_commit_free(commit);
+	git_tag_free(tag);
+}
+
+/**
+ * #### Tree Parsing
+ *
+ * [Tree parsing][tp] is a bit different than the other objects, in that
+ * we have a subtype which is the tree entry.  This is not an actual
+ * object type in Git, but a useful structure for parsing and traversing
+ * tree entries.
+ *
+ * [tp]: http://libgit2.github.com/libgit2/#HEAD/group/tree
+ */
+static void tree_parsing(git_repository *repo)
+{
+	const git_tree_entry *entry;
+	size_t cnt;
+	git_object *obj;
+	git_tree *tree;
+	git_oid oid;
+
+	printf("\n*Tree Parsing*\n");
+
+	/**
+	 * Create the oid and lookup the tree object just like the other objects.
+	 */
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(&oid, "f60079018b664e4e79329a7ef9559c8d9e0378d1", GIT_OID_SHA1);
+#else
+	git_oid_fromstr(&oid, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+#endif
+	git_tree_lookup(&tree, repo, &oid);
+
+	/**
+	 * Getting the count of entries in the tree so you can iterate over them
+	 * if you want to.
+	 */
+	cnt = git_tree_entrycount(tree); /* 2 */
+	printf("tree entries: %d\n", (int) cnt);
+
+	entry = git_tree_entry_byindex(tree, 0);
+	printf("Entry name: %s\n", git_tree_entry_name(entry)); /* "README" */
+
+	/**
+	 * You can also access tree entries by name if you know the name of the
+	 * entry you're looking for.
+	 */
+	entry = git_tree_entry_byname(tree, "README");
+	git_tree_entry_name(entry); /* "README" */
+
+	/**
+	 * Once you have the entry object, you can access the content or subtree
+	 * (or commit, in the case of submodules) that it points to.  You can also
+	 * get the mode if you want.
+	 */
+	git_tree_entry_to_object(&obj, repo, entry); /* blob */
+
+	/**
+	 * Remember to close the looked-up object and tree once you are done using it
+	 */
+	git_object_free(obj);
+	git_tree_free(tree);
+}
+
+/**
+ * #### Blob Parsing
+ *
+ * The last object type is the simplest and requires the least parsing
+ * help. Blobs are just file contents and can contain anything, there is
+ * no structure to it. The main advantage to using the [simple blob
+ * api][ba] is that when you're creating blobs you don't have to calculate
+ * the size of the content.  There is also a helper for reading a file
+ * from disk and writing it to the db and getting the oid back so you
+ * don't have to do all those steps yourself.
+ *
+ * [ba]: http://libgit2.github.com/libgit2/#HEAD/group/blob
+ */
+static void blob_parsing(git_repository *repo)
+{
+	git_blob *blob;
+	git_oid oid;
+
+	printf("\n*Blob Parsing*\n");
+
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08", GIT_OID_SHA1);
+#else
+	git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
+#endif
+	git_blob_lookup(&blob, repo, &oid);
+
+	/**
+	 * You can access a buffer with the raw contents of the blob directly.
+	 * Note that this buffer may not be contain ASCII data for certain blobs
+	 * (e.g. binary files): do not consider the buffer a NULL-terminated
+	 * string, and use the `git_blob_rawsize` attribute to find out its exact
+	 * size in bytes
+	 * */
+	printf("Blob Size: %ld\n", (long)git_blob_rawsize(blob)); /* 8 */
+	git_blob_rawcontent(blob); /* "content" */
+
+	/**
+	 * Free the blob after usage.
+	 */
+	git_blob_free(blob);
+}
+
+/**
+ * ### Revwalking
+ *
+ * The libgit2 [revision walking api][rw] provides methods to traverse the
+ * directed graph created by the parent pointers of the commit objects.
+ * Since all commits point back to the commit that came directly before
+ * them, you can walk this parentage as a graph and find all the commits
+ * that were ancestors of (reachable from) a given starting point.  This
+ * can allow you to create `git log` type functionality.
+ *
+ * [rw]: http://libgit2.github.com/libgit2/#HEAD/group/revwalk
+ */
+static void revwalking(git_repository *repo)
+{
+	const git_signature *cauth;
+	const char *cmsg;
+	int error;
+	git_revwalk *walk;
+	git_commit *wcommit;
+	git_oid oid;
+
+	printf("\n*Revwalking*\n");
+
+#ifdef GIT_EXPERIMENTAL_SHA256
+	git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644", GIT_OID_SHA1);
+#else
+	git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+#endif
+
+	/**
+	 * To use the revwalker, create a new walker, tell it how you want to sort
+	 * the output and then push one or more starting points onto the walker.
+	 * If you want to emulate the output of `git log` you would push the SHA
+	 * of the commit that HEAD points to into the walker and then start
+	 * traversing them.  You can also 'hide' commits that you want to stop at
+	 * or not see any of their ancestors.  So if you want to emulate `git log
+	 * branch1..branch2`, you would push the oid of `branch2` and hide the oid
+	 * of `branch1`.
+	 */
+	git_revwalk_new(&walk, repo);
+	git_revwalk_sorting(walk, GIT_SORT_TOPOLOGICAL | GIT_SORT_REVERSE);
+	git_revwalk_push(walk, &oid);
+
+	/**
+	 * Now that we have the starting point pushed onto the walker, we start
+	 * asking for ancestors. It will return them in the sorting order we asked
+	 * for as commit oids.  We can then lookup and parse the committed pointed
+	 * at by the returned OID; note that this operation is specially fast
+	 * since the raw contents of the commit object will be cached in memory
+	 */
+	while ((git_revwalk_next(&oid, walk)) == 0) {
+		error = git_commit_lookup(&wcommit, repo, &oid);
+		check_error(error, "looking up commit during revwalk");
+
+		cmsg  = git_commit_message(wcommit);
+		cauth = git_commit_author(wcommit);
+		printf("%s (%s)\n", cmsg, cauth->email);
+
+		git_commit_free(wcommit);
+	}
+
+	/**
+	 * Like the other objects, be sure to free the revwalker when you're done
+	 * to prevent memory leaks.  Also, make sure that the repository being
+	 * walked it not deallocated while the walk is in progress, or it will
+	 * result in undefined behavior
+	 */
+	git_revwalk_free(walk);
+}
+
+/**
+ * ### Index File Manipulation *
+ * The [index file API][gi] allows you to read, traverse, update and write
+ * the Git index file (sometimes thought of as the staging area).
+ *
+ * [gi]: http://libgit2.github.com/libgit2/#HEAD/group/index
+ */
+static void index_walking(git_repository *repo)
+{
+	git_index *index;
+	size_t i, ecount;
+
+	printf("\n*Index Walking*\n");
+
+	/**
+	 * You can either open the index from the standard location in an open
+	 * repository, as we're doing here, or you can open and manipulate any
+	 * index file with `git_index_open_bare()`. The index for the repository
+	 * will be located and loaded from disk.
+	 */
+	git_repository_index(&index, repo);
+
+	/**
+	 * For each entry in the index, you can get a bunch of information
+	 * including the SHA (oid), path and mode which map to the tree objects
+	 * that are written out.  It also has filesystem properties to help
+	 * determine what to inspect for changes (ctime, mtime, dev, ino, uid,
+	 * gid, file_size and flags) All these properties are exported publicly in
+	 * the `git_index_entry` struct
+	 */
+	ecount = git_index_entrycount(index);
+	for (i = 0; i < ecount; ++i) {
+		const git_index_entry *e = git_index_get_byindex(index, i);
+
+		printf("path: %s\n", e->path);
+		printf("mtime: %d\n", (int)e->mtime.seconds);
+		printf("fs: %d\n", (int)e->file_size);
+	}
+
+	git_index_free(index);
+}
+
+/**
+ * ### References
+ *
+ * The [reference API][ref] allows you to list, resolve, create and update
+ * references such as branches, tags and remote references (everything in
+ * the .git/refs directory).
+ *
+ * [ref]: http://libgit2.github.com/libgit2/#HEAD/group/reference
+ */
+static void reference_listing(git_repository *repo)
+{
+	git_strarray ref_list;
+	unsigned i;
+
+	printf("\n*Reference Listing*\n");
+
+	/**
+	 * Here we will implement something like `git for-each-ref` simply listing
+	 * out all available references and the object SHA they resolve to.
+	 *
+	 * Now that we have the list of reference names, we can lookup each ref
+	 * one at a time and resolve them to the SHA, then print both values out.
+	 */
+
+	git_reference_list(&ref_list, repo);
+
+	for (i = 0; i < ref_list.count; ++i) {
+		git_reference *ref;
+		char oid_hex[GIT_OID_SHA1_HEXSIZE+1] = GIT_OID_SHA1_HEXZERO;
+		const char *refname;
+
+		refname = ref_list.strings[i];
+		git_reference_lookup(&ref, repo, refname);
+
+		switch (git_reference_type(ref)) {
+			case GIT_REFERENCE_DIRECT:
+				git_oid_fmt(oid_hex, git_reference_target(ref));
+				printf("%s [%s]\n", refname, oid_hex);
+				break;
+
+			case GIT_REFERENCE_SYMBOLIC:
+				printf("%s => %s\n", refname, git_reference_symbolic_target(ref));
+				break;
+			default:
+				fprintf(stderr, "Unexpected reference type\n");
+				exit(1);
+		}
+
+		git_reference_free(ref);
+	}
+
+	git_strarray_dispose(&ref_list);
+}
+
+/**
+ * ### Config Files
+ *
+ * The [config API][config] allows you to list and update config values
+ * in any of the accessible config file locations (system, global, local).
+ *
+ * [config]: http://libgit2.github.com/libgit2/#HEAD/group/config
+ */
+static void config_files(const char *repo_path, git_repository* repo)
+{
+	const char *email;
+	char config_path[256];
+	int32_t autocorrect;
+	git_config *cfg;
+	git_config *snap_cfg;
+	int error_code;
+
+	printf("\n*Config Listing*\n");
+
+	/**
+	 * Open a config object so we can read global values from it.
+	 */
+	sprintf(config_path, "%s/config", repo_path);
+	check_error(git_config_open_ondisk(&cfg, config_path), "opening config");
+
+	if (git_config_get_int32(&autocorrect, cfg, "help.autocorrect") == 0)
+		printf("Autocorrect: %d\n", autocorrect);
+
+	check_error(git_repository_config_snapshot(&snap_cfg, repo), "config snapshot");
+	git_config_get_string(&email, snap_cfg, "user.email");
+	printf("Email: %s\n", email);
+
+	error_code = git_config_get_int32(&autocorrect, cfg, "help.autocorrect");
+	switch (error_code)
+	{
+		case 0:
+			printf("Autocorrect: %d\n", autocorrect);
+			break;
+		case GIT_ENOTFOUND:
+			printf("Autocorrect: Undefined\n");
+			break;
+		default:
+			check_error(error_code, "get_int32 failed");
+	}
+	git_config_free(cfg);
+
+	check_error(git_repository_config_snapshot(&snap_cfg, repo), "config snapshot");
+	error_code = git_config_get_string(&email, snap_cfg, "user.email");
+	switch (error_code)
+	{
+		case 0:
+			printf("Email: %s\n", email);
+			break;
+		case GIT_ENOTFOUND:
+			printf("Email: Undefined\n");
+			break;
+		default:
+			check_error(error_code, "get_string failed");
+	}
+
+	git_config_free(snap_cfg);
+}