Commit 176d58bad44d5cc3b286c5744c4cae1c283cb00d

Patrick Steinhardt 2016-08-16T09:17:12

examples: general: use tabs instead of spaces

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diff --git a/examples/general.c b/examples/general.c
index 32fdaf4..036cd9e 100644
--- a/examples/general.c
+++ b/examples/general.c
@@ -52,479 +52,479 @@ static void check_error(int error_code, const char *action)
 		return;
 
 	printf("Error %d %s - %s\n", error_code, action,
-		   (error && error->message) ? error->message : "???");
+			(error && error->message) ? error->message : "???");
 
 	exit(1);
 }
 
 int main (int argc, char** argv)
 {
-  // Initialize the library, this will set up any global state which libgit2 needs
-  // including threading and crypto
-  git_libgit2_init();
+	// Initialize the library, this will set up any global state which libgit2 needs
+	// including threading and crypto
+	git_libgit2_init();
 
-  // ### Opening the Repository
+	// ### 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.
+	// 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
-  int error;
-  const char *repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git";
-  git_repository *repo;
-
-  error = git_repository_open(&repo, repo_path);
-  check_error(error, "opening repository");
-
-  // ### SHA-1 Value Conversions
-
-  // For our first example, we will convert a 40 character hex value to the
-  // 20 byte raw SHA1 value.
-  printf("*Hex to Raw*\n");
-  char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045";
-
-  // 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.
-  git_oid oid;
-  git_oid_fromstr(&oid, hex);
-
-  // 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");
-  char out[GIT_OID_HEXSZ+1];
-  out[GIT_OID_HEXSZ] = '\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
-  git_odb *odb;
-  git_repository_odb(&odb, repo);
-
-  // #### Raw Object Reading
-
-  printf("\n*Raw Object Read*\n");
-  git_odb_object *obj;
-  git_otype otype;
-  const unsigned char *data;
-  const char *str_type;
-
-  // 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\n",
-      (int)git_odb_object_size(obj),
-      str_type);
-
-  // 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_OBJ_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(out, &oid);
-  printf("Written Object: %s\n", out);
-
-  // ### 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
-
-  printf("\n*Commit Parsing*\n");
-
-  git_commit *commit;
-  git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479");
-
-  error = git_commit_lookup(&commit, repo, &oid);
-  check_error(error, "looking up commit");
-
-  const git_signature *author, *cmtter;
-  const char *message;
-  time_t ctime;
-  unsigned int parents, p;
-
-  // 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);
-  ctime    = 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)\n", author->name, author->email);
-
-  // 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++) {
-    git_commit *parent;
-    git_commit_parent(&parent, commit, p);
-    git_oid_fmt(out, git_commit_id(parent));
-    printf("Parent: %s\n", out);
-    git_commit_free(parent);
-  }
-
-  // Don't forget to close the object to prevent memory leaks. You will have
-  // to do this for all the objects you open and parse.
-  git_commit_free(commit);
-
-  // #### 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
-
-  printf("\n*Commit Writing*\n");
-  git_oid tree_id, parent_id, commit_id;
-  git_tree *tree;
-  git_commit *parent;
-
-  // 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((git_signature **)&author,
-      "Scott Chacon", "schacon@gmail.com", 123456789, 60);
-  git_signature_new((git_signature **)&cmtter,
-      "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
-  git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
-  git_tree_lookup(&tree, repo, &tree_id);
-  git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
-  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,
-    cmtter,
-    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(out, &commit_id);
-  printf("New Commit: %s\n", out);
-
-  // #### 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
-  printf("\n*Tag Parsing*\n");
-  git_tag *tag;
-  const char *tmessage, *tname;
-  git_otype ttype;
-
-  // 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).
-  git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1");
-
-  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);
-  tname = git_tag_name(tag);		// "test"
-  ttype = git_tag_target_type(tag);	// GIT_OBJ_COMMIT (otype enum)
-  tmessage = git_tag_message(tag);	// "tag message\n"
-  printf("Tag Message: %s\n", tmessage);
-
-  git_commit_free(commit);
-
-  // #### 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
-  printf("\n*Tree Parsing*\n");
-
-  const git_tree_entry *entry;
-  git_object *objt;
-
-  // Create the oid and lookup the tree object just like the other objects.
-  git_oid_fromstr(&oid, "2a741c18ac5ff082a7caaec6e74db3075a1906b5");
-  git_tree_lookup(&tree, repo, &oid);
-
-  // Getting the count of entries in the tree so you can iterate over them
-  // if you want to.
-  size_t cnt = git_tree_entrycount(tree); // 3
-  printf("tree entries: %d\n", (int)cnt);
-
-  entry = git_tree_entry_byindex(tree, 0);
-  printf("Entry name: %s\n", git_tree_entry_name(entry)); // "hello.c"
-
-  // 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); // "hello.c"
-
-  // 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(&objt, repo, entry); // blob
-
-  // Remember to close the looked-up object once you are done using it
-  git_object_free(objt);
-
-  // #### 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
-
-  printf("\n*Blob Parsing*\n");
-  git_blob *blob;
-
-  git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
-  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"
-
-  // ### 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
-
-  printf("\n*Revwalking*\n");
-  git_revwalk *walk;
-  git_commit *wcommit;
-
-  git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
-
-  // 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);
-
-  const git_signature *cauth;
-  const char *cmsg;
-
-  // 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
-
-  printf("\n*Index Walking*\n");
-
-  git_index *index;
-  unsigned int i, ecount;
-
-  // 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
-
-  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.
-  git_strarray ref_list;
-  git_reference_list(&ref_list, repo);
-
-  const char *refname;
-  git_reference *ref;
-
-  // 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.
-  for (i = 0; i < ref_list.count; ++i) {
-    refname = ref_list.strings[i];
-    git_reference_lookup(&ref, repo, refname);
-
-    switch (git_reference_type(ref)) {
-    case GIT_REF_OID:
-      git_oid_fmt(out, git_reference_target(ref));
-      printf("%s [%s]\n", refname, out);
-      break;
-
-    case GIT_REF_SYMBOLIC:
-      printf("%s => %s\n", refname, git_reference_symbolic_target(ref));
-      break;
-    default:
-      fprintf(stderr, "Unexpected reference type\n");
-      exit(1);
-    }
-  }
-
-  git_strarray_free(&ref_list);
-
-  // ### Config Files
-
-  // The [config API][config] allows you to list and updatee config values
-  // in any of the accessible config file locations (system, global, local).
-  //
-  // [config]: http://libgit2.github.com/libgit2/#HEAD/group/config
+	//
+	// [me]: http://libgit2.github.com/libgit2/#HEAD/group/repository
+	int error;
+	const char *repo_path = (argc > 1) ? argv[1] : "/opt/libgit2-test/.git";
+	git_repository *repo;
+
+	error = git_repository_open(&repo, repo_path);
+	check_error(error, "opening repository");
+
+	// ### SHA-1 Value Conversions
+
+	// For our first example, we will convert a 40 character hex value to the
+	// 20 byte raw SHA1 value.
+	printf("*Hex to Raw*\n");
+	char hex[] = "4a202b346bb0fb0db7eff3cffeb3c70babbd2045";
+
+	// 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.
+	git_oid oid;
+	git_oid_fromstr(&oid, hex);
+
+	// 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");
+	char out[GIT_OID_HEXSZ+1];
+	out[GIT_OID_HEXSZ] = '\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
+	git_odb *odb;
+	git_repository_odb(&odb, repo);
+
+	// #### Raw Object Reading
+
+	printf("\n*Raw Object Read*\n");
+	git_odb_object *obj;
+	git_otype otype;
+	const unsigned char *data;
+	const char *str_type;
+
+	// 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\n",
+			(int)git_odb_object_size(obj),
+			str_type);
+
+	// 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_OBJ_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(out, &oid);
+	printf("Written Object: %s\n", out);
+
+	// ### 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
+
+	printf("\n*Commit Parsing*\n");
+
+	git_commit *commit;
+	git_oid_fromstr(&oid, "8496071c1b46c854b31185ea97743be6a8774479");
+
+	error = git_commit_lookup(&commit, repo, &oid);
+	check_error(error, "looking up commit");
+
+	const git_signature *author, *cmtter;
+	const char *message;
+	time_t ctime;
+	unsigned int parents, p;
+
+	// 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);
+	ctime    = 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)\n", author->name, author->email);
+
+	// 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++) {
+		git_commit *parent;
+		git_commit_parent(&parent, commit, p);
+		git_oid_fmt(out, git_commit_id(parent));
+		printf("Parent: %s\n", out);
+		git_commit_free(parent);
+	}
+
+	// Don't forget to close the object to prevent memory leaks. You will have
+	// to do this for all the objects you open and parse.
+	git_commit_free(commit);
+
+	// #### 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
+
+	printf("\n*Commit Writing*\n");
+	git_oid tree_id, parent_id, commit_id;
+	git_tree *tree;
+	git_commit *parent;
+
+	// 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((git_signature **)&author,
+			"Scott Chacon", "schacon@gmail.com", 123456789, 60);
+	git_signature_new((git_signature **)&cmtter,
+			"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
+	git_oid_fromstr(&tree_id, "f60079018b664e4e79329a7ef9559c8d9e0378d1");
+	git_tree_lookup(&tree, repo, &tree_id);
+	git_oid_fromstr(&parent_id, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+	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,
+			cmtter,
+			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(out, &commit_id);
+	printf("New Commit: %s\n", out);
+
+	// #### 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
+	printf("\n*Tag Parsing*\n");
+	git_tag *tag;
+	const char *tmessage, *tname;
+	git_otype ttype;
+
+	// 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).
+	git_oid_fromstr(&oid, "b25fa35b38051e4ae45d4222e795f9df2e43f1d1");
+
+	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);
+	tname = git_tag_name(tag);		// "test"
+	ttype = git_tag_target_type(tag);	// GIT_OBJ_COMMIT (otype enum)
+	tmessage = git_tag_message(tag);	// "tag message\n"
+	printf("Tag Message: %s\n", tmessage);
+
+	git_commit_free(commit);
+
+	// #### 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
+	printf("\n*Tree Parsing*\n");
+
+	const git_tree_entry *entry;
+	git_object *objt;
+
+	// Create the oid and lookup the tree object just like the other objects.
+	git_oid_fromstr(&oid, "2a741c18ac5ff082a7caaec6e74db3075a1906b5");
+	git_tree_lookup(&tree, repo, &oid);
+
+	// Getting the count of entries in the tree so you can iterate over them
+	// if you want to.
+	size_t cnt = git_tree_entrycount(tree); // 3
+	printf("tree entries: %d\n", (int)cnt);
+
+	entry = git_tree_entry_byindex(tree, 0);
+	printf("Entry name: %s\n", git_tree_entry_name(entry)); // "hello.c"
+
+	// 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); // "hello.c"
+
+	// 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(&objt, repo, entry); // blob
+
+	// Remember to close the looked-up object once you are done using it
+	git_object_free(objt);
+
+	// #### 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
+
+	printf("\n*Blob Parsing*\n");
+	git_blob *blob;
+
+	git_oid_fromstr(&oid, "1385f264afb75a56a5bec74243be9b367ba4ca08");
+	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"
+
+	// ### 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
+
+	printf("\n*Revwalking*\n");
+	git_revwalk *walk;
+	git_commit *wcommit;
+
+	git_oid_fromstr(&oid, "5b5b025afb0b4c913b4c338a42934a3863bf3644");
+
+	// 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);
+
+	const git_signature *cauth;
+	const char *cmsg;
+
+	// 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
+
+	printf("\n*Index Walking*\n");
+
+	git_index *index;
+	unsigned int i, ecount;
+
+	// 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
+
+	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.
+	git_strarray ref_list;
+	git_reference_list(&ref_list, repo);
+
+	const char *refname;
+	git_reference *ref;
+
+	// 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.
+	for (i = 0; i < ref_list.count; ++i) {
+		refname = ref_list.strings[i];
+		git_reference_lookup(&ref, repo, refname);
+
+		switch (git_reference_type(ref)) {
+			case GIT_REF_OID:
+				git_oid_fmt(out, git_reference_target(ref));
+				printf("%s [%s]\n", refname, out);
+				break;
+
+			case GIT_REF_SYMBOLIC:
+				printf("%s => %s\n", refname, git_reference_symbolic_target(ref));
+				break;
+			default:
+				fprintf(stderr, "Unexpected reference type\n");
+				exit(1);
+		}
+	}
+
+	git_strarray_free(&ref_list);
+
+	// ### Config Files
+
+	// The [config API][config] allows you to list and updatee config values
+	// in any of the accessible config file locations (system, global, local).
+	//
+	// [config]: http://libgit2.github.com/libgit2/#HEAD/group/config
 
-  printf("\n*Config Listing*\n");
+	printf("\n*Config Listing*\n");
 
-  const char *email;
-  int32_t j;
+	const char *email;
+	int32_t j;
 
-  git_config *cfg;
+	git_config *cfg;
 
-  // Open a config object so we can read global values from it.
-  char config_path[256];
-  sprintf(config_path, "%s/config", repo_path);
-  check_error(git_config_open_ondisk(&cfg, config_path), "opening config");
+	// Open a config object so we can read global values from it.
+	char config_path[256];
+	sprintf(config_path, "%s/config", repo_path);
+	check_error(git_config_open_ondisk(&cfg, config_path), "opening config");
 
-  git_config_get_int32(&j, cfg, "help.autocorrect");
-  printf("Autocorrect: %d\n", j);
+	git_config_get_int32(&j, cfg, "help.autocorrect");
+	printf("Autocorrect: %d\n", j);
 
-  git_config_get_string(&email, cfg, "user.email");
-  printf("Email: %s\n", email);
+	git_config_get_string(&email, cfg, "user.email");
+	printf("Email: %s\n", email);
 
-  // Finally, when you're done with the repository, you can free it as well.
-  git_repository_free(repo);
+	// Finally, when you're done with the repository, you can free it as well.
+	git_repository_free(repo);
 
-  return 0;
+	return 0;
 }