Merge pull request #5272 from tiennou/examples/cli-ification

Various examples shape-ups

22 files changed, 521 insertions, 444 deletions

diff --git a/examples/CMakeLists.txt b/examples/CMakeLists.txt
index 05e344df1..8cc72b35e 100644
--- a/examples/CMakeLists.txt
+++ b/examples/CMakeLists.txt
@@ -1,7 +1,7 @@
 INCLUDE_DIRECTORIES(${LIBGIT2_INCLUDES})
 INCLUDE_DIRECTORIES(SYSTEM ${LIBGIT2_SYSTEM_INCLUDES})
 
-FILE(GLOB LG2_SOURCES *.c)
+FILE(GLOB LG2_SOURCES *.c *.h)
 ADD_EXECUTABLE(lg2 ${LG2_SOURCES})
 SET_TARGET_PROPERTIES(lg2 PROPERTIES C_STANDARD 90)
 
diff --git a/examples/add.c b/examples/add.c
index 14e69e96f..6e3c239fc 100644
--- a/examples/add.c
+++ b/examples/add.c
@@ -13,7 +13,6 @@
  */
 
 #include "common.h"
-#include <assert.h>
 
 /**
  * The following example demonstrates how to add files with libgit2.
@@ -27,48 +26,50 @@
  *   -u/--update: update the index instead of adding to it.
  */
 
-enum print_options {
-	SKIP = 1,
-	VERBOSE = 2,
-	UPDATE = 4,
+enum index_mode {
+	INDEX_NONE,
+	INDEX_ADD,
 };
 
-struct print_payload {
-	enum print_options options;
+struct index_options {
+	int dry_run;
+	int verbose;
 	git_repository *repo;
+	enum index_mode mode;
+	int add_update;
 };
 
 /* Forward declarations for helpers */
-static void parse_opts(int *options, int *count, int argc, char *argv[]);
-void init_array(git_strarray *array, int argc, char **argv);
+static void parse_opts(const char **repo_path, struct index_options *opts, struct args_info *args);
 int print_matched_cb(const char *path, const char *matched_pathspec, void *payload);
 
-int lg2_add(git_repository *repo, int argc, char** argv)
+int lg2_add(git_repository *repo, int argc, char **argv)
 {
 	git_index_matched_path_cb matched_cb = NULL;
 	git_index *index;
 	git_strarray array = {0};
-	int options = 0, count = 0;
-	struct print_payload payload = {0};
+	struct index_options options;
+	struct args_info args = ARGS_INFO_INIT;
 
-	parse_opts(&options, &count, argc, argv);
-	init_array(&array, argc-count, argv+count);
+	/* Parse the options & arguments. */
+	parse_opts(NULL, &options, &args);
+	strarray_from_args(&array, &args);
 
+	/* Grab the repository's index. */
 	check_lg2(git_repository_index(&index, repo), "Could not open repository index", NULL);
 
 	/* Setup a callback if the requested options need it */
-	if ((options & VERBOSE) || (options & SKIP)) {
+	if (options.verbose || options.dry_run) {
 		matched_cb = &print_matched_cb;
 	}
 
-	/* Perform the requested action with the index and files */
-	payload.options = options;
-	payload.repo = repo;
+	options.repo = repo;
 
-	if (options & UPDATE) {
-		git_index_update_all(index, &array, matched_cb, &payload);
+	/* Perform the requested action with the index and files */
+	if (options.add_update) {
+		git_index_update_all(index, &array, matched_cb, &options);
 	} else {
-		git_index_add_all(index, &array, 0, matched_cb, &payload);
+		git_index_add_all(index, &array, 0, matched_cb, &options);
 	}
 
 	/* Cleanup memory */
@@ -85,15 +86,14 @@ int lg2_add(git_repository *repo, int argc, char** argv)
  */
 int print_matched_cb(const char *path, const char *matched_pathspec, void *payload)
 {
-	struct print_payload p = *(struct print_payload*)(payload);
+	struct index_options *opts = (struct index_options *)(payload);
 	int ret;
 	unsigned status;
 	(void)matched_pathspec;
 
 	/* Get the file status */
-	if (git_status_file(&status, p.repo, path)) {
+	if (git_status_file(&status, opts->repo, path) < 0)
 		return -1;
-	}
 
 	if ((status & GIT_STATUS_WT_MODIFIED) || (status & GIT_STATUS_WT_NEW)) {
 		printf("add '%s'\n", path);
@@ -102,9 +102,8 @@ int print_matched_cb(const char *path, const char *matched_pathspec, void *paylo
 		ret = 1;
 	}
 
-	if ((p.options & SKIP)) {
+	if (opts->dry_run)
 		ret = 1;
-	}
 
 	return ret;
 }
@@ -133,33 +132,39 @@ void print_usage(void)
 	exit(1);
 }
 
-static void parse_opts(int *options, int *count, int argc, char *argv[])
+static void parse_opts(const char **repo_path, struct index_options *opts, struct args_info *args)
 {
-	int i;
+	if (args->argc <= 1)
+		print_usage();
 
-	for (i = 1; i < argc; ++i) {
-		if (argv[i][0] != '-')
-			break;
-		else if (!strcmp(argv[i], "--verbose") || !strcmp(argv[i], "-v"))
-			*options |= VERBOSE;
-		else if (!strcmp(argv[i], "--dry-run") || !strcmp(argv[i], "-n"))
-			*options |= SKIP;
-		else if (!strcmp(argv[i], "--update") || !strcmp(argv[i], "-u"))
-			*options |= UPDATE;
-		else if (!strcmp(argv[i], "-h")) {
+	for (args->pos = 1; args->pos < args->argc; ++args->pos) {
+		const char *curr = args->argv[args->pos];
+
+		if (curr[0] != '-') {
+			if (!strcmp("add", curr)) {
+				opts->mode = INDEX_ADD;
+				continue;
+			} else if (opts->mode == INDEX_NONE) {
+				fprintf(stderr, "missing command: %s", curr);
+				print_usage();
+				break;
+			} else {
+				/* We might be looking at a filename */
+				break;
+			}
+		} else if (match_bool_arg(&opts->verbose, args, "--verbose") ||
+				   match_bool_arg(&opts->dry_run, args, "--dry-run") ||
+				   match_str_arg(repo_path, args, "--git-dir") ||
+				   (opts->mode == INDEX_ADD && match_bool_arg(&opts->add_update, args, "--update"))) {
+			continue;
+		} else if (match_bool_arg(NULL, args, "--help")) {
 			print_usage();
 			break;
-		} else if (!strcmp(argv[i], "--")) {
-			i++;
+		} else if (match_arg_separator(args)) {
 			break;
 		} else {
-			fprintf(stderr, "Unsupported option %s.\n", argv[i]);
+			fprintf(stderr, "Unsupported option %s.\n", curr);
 			print_usage();
 		}
 	}
-
-	if (argc <= i)
-		print_usage();
-
-	*count = i;
 }
diff --git a/examples/args.c b/examples/args.c
new file mode 100644
index 000000000..533e1579b
--- /dev/null
+++ b/examples/args.c
@@ -0,0 +1,197 @@
+#include "common.h"
+#include "args.h"
+
+size_t is_prefixed(const char *str, const char *pfx)
+{
+	size_t len = strlen(pfx);
+	return strncmp(str, pfx, len) ? 0 : len;
+}
+
+int optional_str_arg(
+	const char **out, struct args_info *args, const char *opt, const char *def)
+{
+	const char *found = args->argv[args->pos];
+	size_t len = is_prefixed(found, opt);
+
+	if (!len)
+		return 0;
+
+	if (!found[len]) {
+		if (args->pos + 1 == args->argc) {
+			*out = def;
+			return 1;
+		}
+		args->pos += 1;
+		*out = args->argv[args->pos];
+		return 1;
+	}
+
+	if (found[len] == '=') {
+		*out = found + len + 1;
+		return 1;
+	}
+
+	return 0;
+}
+
+int match_str_arg(
+	const char **out, struct args_info *args, const char *opt)
+{
+	const char *found = args->argv[args->pos];
+	size_t len = is_prefixed(found, opt);
+
+	if (!len)
+		return 0;
+
+	if (!found[len]) {
+		if (args->pos + 1 == args->argc)
+			fatal("expected value following argument", opt);
+		args->pos += 1;
+		*out = args->argv[args->pos];
+		return 1;
+	}
+
+	if (found[len] == '=') {
+		*out = found + len + 1;
+		return 1;
+	}
+
+	return 0;
+}
+
+static const char *match_numeric_arg(struct args_info *args, const char *opt)
+{
+	const char *found = args->argv[args->pos];
+	size_t len = is_prefixed(found, opt);
+
+	if (!len)
+		return NULL;
+
+	if (!found[len]) {
+		if (args->pos + 1 == args->argc)
+			fatal("expected numeric value following argument", opt);
+		args->pos += 1;
+		found = args->argv[args->pos];
+	} else {
+		found = found + len;
+		if (*found == '=')
+			found++;
+	}
+
+	return found;
+}
+
+int match_uint16_arg(
+	uint16_t *out, struct args_info *args, const char *opt)
+{
+	const char *found = match_numeric_arg(args, opt);
+	uint16_t val;
+	char *endptr = NULL;
+
+	if (!found)
+		return 0;
+
+	val = (uint16_t)strtoul(found, &endptr, 0);
+	if (!endptr || *endptr != '\0')
+		fatal("expected number after argument", opt);
+
+	if (out)
+		*out = val;
+	return 1;
+}
+
+int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt)
+{
+	const char *found = match_numeric_arg(args, opt);
+	uint16_t val;
+	char *endptr = NULL;
+
+	if (!found)
+		return 0;
+
+	val = (uint32_t)strtoul(found, &endptr, 0);
+	if (!endptr || *endptr != '\0')
+		fatal("expected number after argument", opt);
+
+	if (out)
+		*out = val;
+	return 1;
+}
+
+static int match_int_internal(
+	int *out, const char *str, int allow_negative, const char *opt)
+{
+	char *endptr = NULL;
+	int	  val = (int)strtol(str, &endptr, 10);
+
+	if (!endptr || *endptr != '\0')
+		fatal("expected number", opt);
+	else if (val < 0 && !allow_negative)
+		fatal("negative values are not allowed", opt);
+
+	if (out)
+		*out = val;
+
+	return 1;
+}
+
+int match_bool_arg(int *out, struct args_info *args, const char *opt)
+{
+	const char *found = args->argv[args->pos];
+
+	if (!strcmp(found, opt)) {
+		*out = 1;
+		return 1;
+	}
+
+	if (!strncmp(found, "--no-", strlen("--no-")) &&
+	    !strcmp(found + strlen("--no-"), opt + 2)) {
+		*out = 0;
+		return 1;
+	}
+
+	*out = -1;
+	return 0;
+}
+
+int is_integer(int *out, const char *str, int allow_negative)
+{
+	return match_int_internal(out, str, allow_negative, NULL);
+}
+
+int match_int_arg(
+	int *out, struct args_info *args, const char *opt, int allow_negative)
+{
+	const char *found = match_numeric_arg(args, opt);
+	if (!found)
+		return 0;
+	return match_int_internal(out, found, allow_negative, opt);
+}
+
+int match_arg_separator(struct args_info *args)
+{
+	if (args->opts_done)
+		return 1;
+
+	if (strcmp(args->argv[args->pos], "--") != 0)
+		return 0;
+
+	args->opts_done = 1;
+	args->pos++;
+	return 1;
+}
+
+void strarray_from_args(git_strarray *array, struct args_info *args)
+{
+	size_t i;
+
+	array->count = args->argc - args->pos;
+	array->strings = calloc(array->count, sizeof(char *));
+	assert(array->strings != NULL);
+
+	for (i = 0; args->pos < args->argc; ++args->pos) {
+		array->strings[i++] = args->argv[args->pos];
+	}
+	args->pos = args->argc;
+}
diff --git a/examples/args.h b/examples/args.h
new file mode 100644
index 000000000..d626f98c8
--- /dev/null
+++ b/examples/args.h
@@ -0,0 +1,90 @@
+#ifndef INCLUDE_examples_args_h__
+#define INCLUDE_examples_args_h__
+
+/**
+ * Argument-processing helper structure
+ */
+struct args_info {
+	int    argc;
+	char **argv;
+	int    pos;
+	int    opts_done : 1; /**< Did we see a -- separator */
+};
+#define ARGS_INFO_INIT { argc, argv, 0, 0 }
+#define ARGS_CURRENT(args) args->argv[args->pos]
+
+/**
+ * Check if a string has the given prefix.  Returns 0 if not prefixed
+ * or the length of the prefix if it is.
+ */
+extern size_t is_prefixed(const char *str, const char *pfx);
+
+/**
+ * Match an integer string, returning 1 if matched, 0 if not.
+ */
+extern int is_integer(int *out, const char *str, int allow_negative);
+
+/**
+ * Check current `args` entry against `opt` string.  If it matches
+ * exactly, take the next arg as a string; if it matches as a prefix with
+ * an equal sign, take the remainder as a string; if value not supplied,
+ * default value `def` will be given. otherwise return 0.
+ */
+extern int optional_str_arg(
+	const char **out, struct args_info *args, const char *opt, const char *def);
+
+/**
+ * Check current `args` entry against `opt` string.  If it matches
+ * exactly, take the next arg as a string; if it matches as a prefix with
+ * an equal sign, take the remainder as a string; otherwise return 0.
+ */
+extern int match_str_arg(
+	const char **out, struct args_info *args, const char *opt);
+
+/**
+ * Check current `args` entry against `opt` string parsing as uint16.  If
+ * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
+ * is a prefix (equal sign optional), take the remainder of the arg as a
+ * uint16_t value; otherwise return 0.
+ */
+extern int match_uint16_arg(
+	uint16_t *out, struct args_info *args, const char *opt);
+
+/**
+ * Check current `args` entry against `opt` string parsing as uint32.  If
+ * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
+ * is a prefix (equal sign optional), take the remainder of the arg as a
+ * uint32_t value; otherwise return 0.
+ */
+extern int match_uint32_arg(
+	uint32_t *out, struct args_info *args, const char *opt);
+
+/**
+ * Check current `args` entry against `opt` string parsing as int.  If
+ * `opt` matches exactly, take the next arg as an int value; if it matches
+ * as a prefix (equal sign optional), take the remainder of the arg as a
+ * int value; otherwise return 0.
+ */
+extern int match_int_arg(
+	int *out, struct args_info *args, const char *opt, int allow_negative);
+
+/**
+ * Check current `args` entry against a "bool" `opt` (ie. --[no-]progress).
+ * If `opt` matches positively, out will be set to 1, or if `opt` matches
+ * negatively, out will be set to 0, and in both cases 1 will be returned.
+ * If neither the positive or the negative form of opt matched, out will be -1,
+ * and 0 will be returned.
+ */
+extern int match_bool_arg(int *out, struct args_info *args, const char *opt);
+
+/**
+ * Check if we're processing past the single -- separator
+ */
+extern int match_arg_separator(struct args_info *args);
+
+/**
+ * Consume all remaining arguments in a git_strarray
+ */
+extern void strarray_from_args(git_strarray *array, struct args_info *args);
+
+#endif
diff --git a/examples/blame.c b/examples/blame.c
index 469dbd1a1..49350fc0f 100644
--- a/examples/blame.c
+++ b/examples/blame.c
@@ -19,7 +19,7 @@
  * simulate the output of `git blame` and a few of its command line arguments.
  */
 
-struct opts {
+struct blame_opts {
 	char *path;
 	char *commitspec;
 	int C;
@@ -28,14 +28,14 @@ struct opts {
 	int end_line;
 	int F;
 };
-static void parse_opts(struct opts *o, int argc, char *argv[]);
+static void parse_opts(struct blame_opts *o, int argc, char *argv[]);
 
 int lg2_blame(git_repository *repo, int argc, char *argv[])
 {
 	int line, break_on_null_hunk;
 	git_object_size_t i, rawsize;
 	char spec[1024] = {0};
-	struct opts o = {0};
+	struct blame_opts o = {0};
 	const char *rawdata;
 	git_revspec revspec = {0};
 	git_blame_options blameopts = GIT_BLAME_OPTIONS_INIT;
@@ -143,7 +143,7 @@ static void usage(const char *msg, const char *arg)
 }
 
 /** Parse the arguments. */
-static void parse_opts(struct opts *o, int argc, char *argv[])
+static void parse_opts(struct blame_opts *o, int argc, char *argv[])
 {
 	int i;
 	char *bare_args[3] = {0};
diff --git a/examples/cat-file.c b/examples/cat-file.c
index 9b14a7048..b81e9a8da 100644
--- a/examples/cat-file.c
+++ b/examples/cat-file.c
@@ -102,27 +102,28 @@ static void show_tag(const git_tag *tag)
 		printf("\n%s\n", git_tag_message(tag));
 }
 
-enum {
+typedef enum {
 	SHOW_TYPE = 1,
 	SHOW_SIZE = 2,
 	SHOW_NONE = 3,
 	SHOW_PRETTY = 4
-};
+} catfile_mode;
 
 /* Forward declarations for option-parsing helper */
-struct opts {
+struct catfile_options {
 	const char *dir;
 	const char *rev;
-	int action;
+	catfile_mode action;
 	int verbose;
 };
-static void parse_opts(struct opts *o, int argc, char *argv[]);
+
+static void parse_opts(struct catfile_options *o, int argc, char *argv[]);
 
 
 /** Entry point for this command */
 int lg2_cat_file(git_repository *repo, int argc, char *argv[])
 {
-	struct opts o = { ".", NULL, 0, 0 };
+	struct catfile_options o = { ".", NULL, 0, 0 };
 	git_object *obj = NULL;
 	char oidstr[GIT_OID_HEXSZ + 1];
 
@@ -201,7 +202,7 @@ static void usage(const char *message, const char *arg)
 }
 
 /** Parse the command-line options taken from git */
-static void parse_opts(struct opts *o, int argc, char *argv[])
+static void parse_opts(struct catfile_options *o, int argc, char *argv[])
 {
 	struct args_info args = ARGS_INFO_INIT;
 
diff --git a/examples/checkout.c b/examples/checkout.c
index d552eece8..70b51859c 100644
--- a/examples/checkout.c
+++ b/examples/checkout.c
@@ -13,7 +13,6 @@
  */
 
 #include "common.h"
-#include <assert.h>
 
 /* Define the printf format specifer to use for size_t output */
 #if defined(_MSC_VER) || defined(__MINGW32__)
@@ -66,7 +65,7 @@ static void parse_options(const char **repo_path, checkout_options *opts, struct
 		const char *curr = args->argv[args->pos];
 		int bool_arg;
 
-		if (strcmp(curr, "--") == 0) {
+		if (match_arg_separator(args)) {
 			break;
 		} else if (!strcmp(curr, "--force")) {
 			opts->force = 1;
@@ -191,11 +190,7 @@ int lg2_checkout(git_repository *repo, int argc, char **argv)
 		goto cleanup;
 	}
 
-	if (args.pos >= args.argc) {
-		fprintf(stderr, "unhandled\n");
-		err = -1;
-		goto cleanup;
-	} else if (!strcmp("--", args.argv[args.pos])) {
+	if (match_arg_separator(&args)) {
 		/**
 		 * Try to checkout the given path
 		 */
diff --git a/examples/common.c b/examples/common.c
index 22807e129..30f6cdc3b 100644
--- a/examples/common.c
+++ b/examples/common.c
@@ -12,21 +12,14 @@
  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
 
-#include <assert.h>
-#include <stdio.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#ifdef _WIN32
-# include <io.h>
-#else
-# include <fcntl.h>
+
+#include "common.h"
+
+#ifndef _WIN32
 # include <unistd.h>
 #endif
-#include <string.h>
 #include <errno.h>
 
-#include "common.h"
-
 void check_lg2(int error, const char *message, const char *extra)
 {
 	const git_error *lg2err;
@@ -60,174 +53,6 @@ void fatal(const char *message, const char *extra)
 	exit(1);
 }
 
-size_t is_prefixed(const char *str, const char *pfx)
-{
-	size_t len = strlen(pfx);
-	return strncmp(str, pfx, len) ? 0 : len;
-}
-
-int optional_str_arg(
-	const char **out, struct args_info *args, const char *opt, const char *def)
-{
-	const char *found = args->argv[args->pos];
-	size_t len = is_prefixed(found, opt);
-
-	if (!len)
-		return 0;
-
-	if (!found[len]) {
-		if (args->pos + 1 == args->argc) {
-			*out = def;
-			return 1;
-		}
-		args->pos += 1;
-		*out = args->argv[args->pos];
-		return 1;
-	}
-
-	if (found[len] == '=') {
-		*out = found + len + 1;
-		return 1;
-	}
-
-	return 0;
-}
-
-int match_str_arg(
-	const char **out, struct args_info *args, const char *opt)
-{
-	const char *found = args->argv[args->pos];
-	size_t len = is_prefixed(found, opt);
-
-	if (!len)
-		return 0;
-
-	if (!found[len]) {
-		if (args->pos + 1 == args->argc)
-			fatal("expected value following argument", opt);
-		args->pos += 1;
-		*out = args->argv[args->pos];
-		return 1;
-	}
-
-	if (found[len] == '=') {
-		*out = found + len + 1;
-		return 1;
-	}
-
-	return 0;
-}
-
-static const char *match_numeric_arg(struct args_info *args, const char *opt)
-{
-	const char *found = args->argv[args->pos];
-	size_t len = is_prefixed(found, opt);
-
-	if (!len)
-		return NULL;
-
-	if (!found[len]) {
-		if (args->pos + 1 == args->argc)
-			fatal("expected numeric value following argument", opt);
-		args->pos += 1;
-		found = args->argv[args->pos];
-	} else {
-		found = found + len;
-		if (*found == '=')
-			found++;
-	}
-
-	return found;
-}
-
-int match_uint16_arg(
-	uint16_t *out, struct args_info *args, const char *opt)
-{
-	const char *found = match_numeric_arg(args, opt);
-	uint16_t val;
-	char *endptr = NULL;
-
-	if (!found)
-		return 0;
-
-	val = (uint16_t)strtoul(found, &endptr, 0);
-	if (!endptr || *endptr != '\0')
-		fatal("expected number after argument", opt);
-
-	if (out)
-		*out = val;
-	return 1;
-}
-
-int match_uint32_arg(
-	uint32_t *out, struct args_info *args, const char *opt)
-{
-	const char *found = match_numeric_arg(args, opt);
-	uint16_t val;
-	char *endptr = NULL;
-
-	if (!found)
-		return 0;
-
-	val = (uint32_t)strtoul(found, &endptr, 0);
-	if (!endptr || *endptr != '\0')
-		fatal("expected number after argument", opt);
-
-	if (out)
-		*out = val;
-	return 1;
-}
-
-static int match_int_internal(
-	int *out, const char *str, int allow_negative, const char *opt)
-{
-	char *endptr = NULL;
-	int	  val = (int)strtol(str, &endptr, 10);
-
-	if (!endptr || *endptr != '\0')
-		fatal("expected number", opt);
-	else if (val < 0 && !allow_negative)
-		fatal("negative values are not allowed", opt);
-
-	if (out)
-		*out = val;
-
-	return 1;
-}
-
-int match_bool_arg(int *out, struct args_info *args, const char *opt)
-{
-	const char *found = args->argv[args->pos];
-
-	if (!strcmp(found, opt)) {
-		*out = 1;
-		return 1;
-	}
-
-	if (!strncmp(found, "--no-", strlen("--no-")) &&
-	    !strcmp(found + strlen("--no-"), opt + 2)) {
-		*out = 0;
-		return 1;
-	}
-
-	*out = -1;
-	return 0;
-}
-
-int is_integer(int *out, const char *str, int allow_negative)
-{
-	return match_int_internal(out, str, allow_negative, NULL);
-}
-
-int match_int_arg(
-	int *out, struct args_info *args, const char *opt, int allow_negative)
-{
-	const char *found = match_numeric_arg(args, opt);
-	if (!found)
-		return 0;
-	return match_int_internal(out, found, allow_negative, opt);
-}
-
 int diff_output(
 	const git_diff_delta *d,
 	const git_diff_hunk *h,
diff --git a/examples/common.h b/examples/common.h
index 2ad897bca..5a029b49a 100644
--- a/examples/common.h
+++ b/examples/common.h
@@ -11,7 +11,10 @@
  * with this software. If not, see
  * <http://creativecommons.org/publicdomain/zero/1.0/>.
  */
+#ifndef INCLUDE_examples_common_h__
+#define INCLUDE_examples_common_h__
 
+#include <assert.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <stdio.h>
@@ -49,6 +52,8 @@
 #define ARRAY_SIZE(x) (sizeof(x)/sizeof(*x))
 #define UNUSED(x) (void)(x)
 
+#include "args.h"
+
 extern int lg2_add(git_repository *repo, int argc, char **argv);
 extern int lg2_blame(git_repository *repo, int argc, char **argv);
 extern int lg2_cat_file(git_repository *repo, int argc, char **argv);
@@ -94,77 +99,6 @@ extern char *read_file(const char *path);
 extern void fatal(const char *message, const char *extra);
 
 /**
- * Check if a string has the given prefix.  Returns 0 if not prefixed
- * or the length of the prefix if it is.
- */
-extern size_t is_prefixed(const char *str, const char *pfx);
-
-/**
- * Match an integer string, returning 1 if matched, 0 if not.
- */
-extern int is_integer(int *out, const char *str, int allow_negative);
-
-struct args_info {
-	int    argc;
-	char **argv;
-	int    pos;
-};
-#define ARGS_INFO_INIT { argc, argv, 0 }
-
-/**
- * Check current `args` entry against `opt` string.  If it matches
- * exactly, take the next arg as a string; if it matches as a prefix with
- * an equal sign, take the remainder as a string; if value not supplied,
- * default value `def` will be given. otherwise return 0.
- */
-extern int optional_str_arg(
-	const char **out, struct args_info *args, const char *opt, const char *def);
-
-/**
- * Check current `args` entry against `opt` string.  If it matches
- * exactly, take the next arg as a string; if it matches as a prefix with
- * an equal sign, take the remainder as a string; otherwise return 0.
- */
-extern int match_str_arg(
-	const char **out, struct args_info *args, const char *opt);
-
-/**
- * Check current `args` entry against `opt` string parsing as uint16.  If
- * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
- * is a prefix (equal sign optional), take the remainder of the arg as a
- * uint16_t value; otherwise return 0.
- */
-extern int match_uint16_arg(
-	uint16_t *out, struct args_info *args, const char *opt);
-
-/**
- * Check current `args` entry against `opt` string parsing as uint32.  If
- * `opt` matches exactly, take the next arg as a uint16_t value; if `opt`
- * is a prefix (equal sign optional), take the remainder of the arg as a
- * uint32_t value; otherwise return 0.
- */
-extern int match_uint32_arg(
-	uint32_t *out, struct args_info *args, const char *opt);
-
-/**
- * Check current `args` entry against `opt` string parsing as int.  If
- * `opt` matches exactly, take the next arg as an int value; if it matches
- * as a prefix (equal sign optional), take the remainder of the arg as a
- * int value; otherwise return 0.
- */
-extern int match_int_arg(
-	int *out, struct args_info *args, const char *opt, int allow_negative);
-
-/**
- * Check current `args` entry against a "bool" `opt` (ie. --[no-]progress).
- * If `opt` matches positively, out will be set to 1, or if `opt` matches
- * negatively, out will be set to 0, and in both cases 1 will be returned.
- * If neither the positive or the negative form of opt matched, out will be -1,
- * and 0 will be returned.
- */
-extern int match_bool_arg(int *out, struct args_info *args, const char *opt);
-
-/**
  * Basic output function for plain text diff output
  * Pass `FILE*` such as `stdout` or `stderr` as payload (or NULL == `stdout`)
  */
@@ -196,3 +130,5 @@ extern int cred_acquire_cb(git_cred **out,
 		const char *username_from_url,
 		unsigned int allowed_types,
 		void *payload);
+
+#endif
diff --git a/examples/describe.c b/examples/describe.c
index 53f548c8b..1236272a1 100644
--- a/examples/describe.c
+++ b/examples/describe.c
@@ -13,7 +13,6 @@
  */
 
 #include "common.h"
-#include <assert.h>
 
 /**
  * The following example partially reimplements the `git describe` command
@@ -38,16 +37,14 @@
  */
 
 /** describe_options represents the parsed command line options */
-typedef struct {
+struct describe_options {
 	const char **commits;
 	size_t commit_count;
 	git_describe_options describe_options;
 	git_describe_format_options format_options;
-} describe_options;
+};
 
-typedef struct args_info args_info;
-
-static void opts_add_commit(describe_options *opts, const char *commit)
+static void opts_add_commit(struct describe_options *opts, const char *commit)
 {
 	size_t sz;
 
@@ -58,7 +55,7 @@ static void opts_add_commit(describe_options *opts, const char *commit)
 	opts->commits[opts->commit_count - 1] = commit;
 }
 
-static void do_describe_single(git_repository *repo, describe_options *opts, const char *rev)
+static void do_describe_single(git_repository *repo, struct describe_options *opts, const char *rev)
 {
 	git_object *commit;
 	git_describe_result *describe_result;
@@ -81,7 +78,7 @@ static void do_describe_single(git_repository *repo, describe_options *opts, con
 	printf("%s\n", buf.ptr);
 }
 
-static void do_describe(git_repository *repo, describe_options *opts)
+static void do_describe(git_repository *repo, struct describe_options *opts)
 {
 	if (opts->commit_count == 0)
 		do_describe_single(repo, opts, NULL);
@@ -100,9 +97,9 @@ static void print_usage(void)
 }
 
 /** Parse command line arguments */
-static void parse_options(describe_options *opts, int argc, char **argv)
+static void parse_options(struct describe_options *opts, int argc, char **argv)
 {
-	args_info args = ARGS_INFO_INIT;
+	struct args_info args = ARGS_INFO_INIT;
 
 	for (args.pos = 1; args.pos < argc; ++args.pos) {
 		const char *curr = argv[args.pos];
@@ -142,7 +139,7 @@ static void parse_options(describe_options *opts, int argc, char **argv)
 }
 
 /** Initialize describe_options struct */
-static void describe_options_init(describe_options *opts)
+static void describe_options_init(struct describe_options *opts)
 {
 	memset(opts, 0, sizeof(*opts));
 
@@ -154,7 +151,7 @@ static void describe_options_init(describe_options *opts)
 
 int lg2_describe(git_repository *repo, int argc, char **argv)
 {
-	describe_options opts;
+	struct describe_options opts;
 
 	describe_options_init(&opts);
 	parse_options(&opts, argc, argv);
diff --git a/examples/diff.c b/examples/diff.c
index 9e2aa9c41..2305c8652 100644
--- a/examples/diff.c
+++ b/examples/diff.c
@@ -47,8 +47,8 @@ enum {
 	CACHE_NONE = 2
 };
 
-/** The 'opts' struct captures all the various parsed command line options. */
-struct opts {
+/** The 'diff_options' struct captures all the various parsed command line options. */
+struct diff_options {
 	git_diff_options diffopts;
 	git_diff_find_options findopts;
 	int color;
@@ -63,18 +63,17 @@ struct opts {
 
 /** These functions are implemented at the end */
 static void usage(const char *message, const char *arg);
-static void parse_opts(struct opts *o, int argc, char *argv[]);
+static void parse_opts(struct diff_options *o, int argc, char *argv[]);
 static int color_printer(
 	const git_diff_delta*, const git_diff_hunk*, const git_diff_line*, void*);
-static void diff_print_stats(git_diff *diff, struct opts *o);
-static void compute_diff_no_index(git_diff **diff, struct opts *o);
+static void diff_print_stats(git_diff *diff, struct diff_options *o);
+static void compute_diff_no_index(git_diff **diff, struct diff_options *o);
 
 int lg2_diff(git_repository *repo, int argc, char *argv[])
 {
 	git_tree *t1 = NULL, *t2 = NULL;
 	git_diff *diff;
-
-	struct opts o = {
+	struct diff_options o = {
 		GIT_DIFF_OPTIONS_INIT, GIT_DIFF_FIND_OPTIONS_INIT,
 		-1, -1, 0, 0, GIT_DIFF_FORMAT_PATCH, NULL, NULL, "."
 	};
@@ -166,7 +165,7 @@ int lg2_diff(git_repository *repo, int argc, char *argv[])
 	return 0;
 }
 
-static void compute_diff_no_index(git_diff **diff, struct opts *o) {
+static void compute_diff_no_index(git_diff **diff, struct diff_options *o) {
 	git_patch *patch = NULL;
 	char *file1_str = NULL;
 	char *file2_str = NULL;
@@ -242,11 +241,10 @@ static int color_printer(
 }
 
 /** Parse arguments as copied from git-diff. */
-static void parse_opts(struct opts *o, int argc, char *argv[])
+static void parse_opts(struct diff_options *o, int argc, char *argv[])
 {
 	struct args_info args = ARGS_INFO_INIT;
 
-
 	for (args.pos = 1; args.pos < argc; ++args.pos) {
 		const char *a = argv[args.pos];
 
@@ -343,7 +341,7 @@ static void parse_opts(struct opts *o, int argc, char *argv[])
 }
 
 /** Display diff output with "--stat", "--numstat", or "--shortstat" */
-static void diff_print_stats(git_diff *diff, struct opts *o)
+static void diff_print_stats(git_diff *diff, struct diff_options *o)
 {
 	git_diff_stats *stats;
 	git_buf b = GIT_BUF_INIT_CONST(NULL, 0);
diff --git a/examples/for-each-ref.c b/examples/for-each-ref.c
index 900792c12..020dab474 100644
--- a/examples/for-each-ref.c
+++ b/examples/for-each-ref.c
@@ -3,42 +3,42 @@
 
 static int show_ref(git_reference *ref, void *data)
 {
-        git_repository *repo = data;
-        git_reference *resolved = NULL;
-        char hex[GIT_OID_HEXSZ+1];
-        const git_oid *oid;
-        git_object *obj;
-
-        if (git_reference_type(ref) == GIT_REFERENCE_SYMBOLIC)
-                check_lg2(git_reference_resolve(&resolved, ref),
-                          "Unable to resolve symbolic reference",
-                          git_reference_name(ref));
-
-        oid = git_reference_target(resolved ? resolved : ref);
-        git_oid_fmt(hex, oid);
-        hex[GIT_OID_HEXSZ] = 0;
-        check_lg2(git_object_lookup(&obj, repo, oid, GIT_OBJECT_ANY),
-                  "Unable to lookup object", hex);
-
-        printf("%s %-6s\t%s\n",
-               hex,
-               git_object_type2string(git_object_type(obj)),
-               git_reference_name(ref));
-
-        if (resolved)
-                git_reference_free(resolved);
-        return 0;
+	git_repository *repo = data;
+	git_reference *resolved = NULL;
+	char hex[GIT_OID_HEXSZ+1];
+	const git_oid *oid;
+	git_object *obj;
+	
+	if (git_reference_type(ref) == GIT_REFERENCE_SYMBOLIC)
+		check_lg2(git_reference_resolve(&resolved, ref),
+				  "Unable to resolve symbolic reference",
+				  git_reference_name(ref));
+	
+	oid = git_reference_target(resolved ? resolved : ref);
+	git_oid_fmt(hex, oid);
+	hex[GIT_OID_HEXSZ] = 0;
+	check_lg2(git_object_lookup(&obj, repo, oid, GIT_OBJECT_ANY),
+			  "Unable to lookup object", hex);
+	
+	printf("%s %-6s\t%s\n",
+		   hex,
+		   git_object_type2string(git_object_type(obj)),
+		   git_reference_name(ref));
+	
+	if (resolved)
+		git_reference_free(resolved);
+	return 0;
 }
 
 int lg2_for_each_ref(git_repository *repo, int argc, char **argv)
 {
 	UNUSED(argv);
-
-        if (argc != 1)
-                fatal("Sorry, no for-each-ref options supported yet", NULL);
-
-        check_lg2(git_reference_foreach(repo, show_ref, repo),
-                  "Could not iterate over references", NULL);
-
-        return 0;
+	
+	if (argc != 1)
+		fatal("Sorry, no for-each-ref options supported yet", NULL);
+	
+	check_lg2(git_reference_foreach(repo, show_ref, repo),
+			  "Could not iterate over references", NULL);
+	
+	return 0;
 }
diff --git a/examples/init.c b/examples/init.c
index e9841bc93..2f681c5ae 100644
--- a/examples/init.c
+++ b/examples/init.c
@@ -27,7 +27,7 @@
  */
 
 /** Forward declarations of helpers */
-struct opts {
+struct init_opts {
 	int no_options;
 	int quiet;
 	int bare;
@@ -38,11 +38,11 @@ struct opts {
 	const char *dir;
 };
 static void create_initial_commit(git_repository *repo);
-static void parse_opts(struct opts *o, int argc, char *argv[]);
+static void parse_opts(struct init_opts *o, int argc, char *argv[]);
 
 int lg2_init(git_repository *repo, int argc, char *argv[])
 {
-	struct opts o = { 1, 0, 0, 0, GIT_REPOSITORY_INIT_SHARED_UMASK, 0, 0, 0 };
+	struct init_opts o = { 1, 0, 0, 0, GIT_REPOSITORY_INIT_SHARED_UMASK, 0, 0, 0 };
 
 	parse_opts(&o, argc, argv);
 
@@ -210,7 +210,7 @@ static uint32_t parse_shared(const char *shared)
 	return 0;
 }
 
-static void parse_opts(struct opts *o, int argc, char *argv[])
+static void parse_opts(struct init_opts *o, int argc, char *argv[])
 {
 	struct args_info args = ARGS_INFO_INIT;
 	const char *sharedarg;
diff --git a/examples/lg2.c b/examples/lg2.c
index f1a8843d2..a3987c34d 100644
--- a/examples/lg2.c
+++ b/examples/lg2.c
@@ -84,8 +84,7 @@ int main(int argc, char **argv)
 			break;
 		} else if (optional_str_arg(&git_dir, &args, "--git-dir", ".git")) {
 			continue;
-		} else if (!strcmp(a, "--")) {
-			/* arg separator */
+		} else if (match_arg_separator(&args)) {
 			break;
 		}
 	}
diff --git a/examples/log.c b/examples/log.c
index a6bd957ae..3eee7d421 100644
--- a/examples/log.c
+++ b/examples/log.c
@@ -424,8 +424,7 @@ static int parse_options(
 			else
 				/** Try failed revision parse as filename. */
 				break;
-		} else if (!strcmp(a, "--")) {
-			++args.pos;
+		} else if (!match_arg_separator(&args)) {
 			break;
 		}
 		else if (!strcmp(a, "--date-order"))
diff --git a/examples/ls-files.c b/examples/ls-files.c
index b82af0124..a23506962 100644
--- a/examples/ls-files.c
+++ b/examples/ls-files.c
@@ -25,11 +25,11 @@
  * This currently supports the default behavior and the `--error-unmatch` option.
  */
 
-typedef struct {
+struct ls_options {
 	int error_unmatch;
 	char *files[1024];
 	size_t file_count;
-} ls_options;
+};
 
 static void usage(const char *message, const char *arg)
 {
@@ -41,12 +41,12 @@ static void usage(const char *message, const char *arg)
 	exit(1);
 }
 
-static int parse_options(ls_options *opts, int argc, char *argv[])
+static int parse_options(struct ls_options *opts, int argc, char *argv[])
 {
 	int parsing_files = 0;
 	int i;
 
-	memset(opts, 0, sizeof(ls_options));
+	memset(opts, 0, sizeof(struct ls_options));
 
 	if (argc < 2)
 		return 0;
@@ -78,7 +78,7 @@ static int parse_options(ls_options *opts, int argc, char *argv[])
 	return 0;
 }
 
-static int print_paths(ls_options *opts, git_index *index)
+static int print_paths(struct ls_options *opts, git_index *index)
 {
 	size_t i;
 	const git_index_entry *entry;
@@ -113,7 +113,7 @@ static int print_paths(ls_options *opts, git_index *index)
 int lg2_ls_files(git_repository *repo, int argc, char *argv[])
 {
 	git_index *index = NULL;
-	ls_options opts;
+	struct ls_options opts;
 	int error;
 
 	if ((error = parse_options(&opts, argc, argv)) < 0)
diff --git a/examples/merge.c b/examples/merge.c
index 995ac021b..460c06a25 100644
--- a/examples/merge.c
+++ b/examples/merge.c
@@ -13,7 +13,6 @@
  */
 
 #include "common.h"
-#include <assert.h>
 
 /** The following example demonstrates how to do merges with libgit2.
  *
@@ -24,7 +23,7 @@
  *
  */
 
-typedef struct {
+struct merge_options {
 	const char **heads;
 	size_t heads_count;
 
@@ -32,7 +31,7 @@ typedef struct {
 	size_t annotated_count;
 
 	int no_commit : 1;
-} merge_options;
+};
 
 static void print_usage(void)
 {
@@ -40,7 +39,7 @@ static void print_usage(void)
 	exit(1);
 }
 
-static void merge_options_init(merge_options *opts)
+static void merge_options_init(struct merge_options *opts)
 {
 	memset(opts, 0, sizeof(*opts));
 
@@ -50,7 +49,7 @@ static void merge_options_init(merge_options *opts)
 	opts->annotated_count = 0;
 }
 
-static void opts_add_refish(merge_options *opts, const char *refish)
+static void opts_add_refish(struct merge_options *opts, const char *refish)
 {
 	size_t sz;
 
@@ -61,7 +60,7 @@ static void opts_add_refish(merge_options *opts, const char *refish)
 	opts->heads[opts->heads_count - 1] = refish;
 }
 
-static void parse_options(const char **repo_path, merge_options *opts, int argc, char **argv)
+static void parse_options(const char **repo_path, struct merge_options *opts, int argc, char **argv)
 {
 	struct args_info args = ARGS_INFO_INIT;
 
@@ -83,7 +82,7 @@ static void parse_options(const char **repo_path, merge_options *opts, int argc,
 	}
 }
 
-static int resolve_heads(git_repository *repo, merge_options *opts)
+static int resolve_heads(git_repository *repo, struct merge_options *opts)
 {
 	git_annotated_commit **annotated = calloc(opts->heads_count, sizeof(git_annotated_commit *));
 	size_t annotated_count = 0, i;
@@ -201,7 +200,7 @@ static void output_conflicts(git_index *index)
 	git_index_conflict_iterator_free(conflicts);
 }
 
-static int create_merge_commit(git_repository *repo, git_index *index, merge_options *opts)
+static int create_merge_commit(git_repository *repo, git_index *index, struct merge_options *opts)
 {
 	git_oid tree_oid, commit_oid;
 	git_tree *tree;
@@ -277,7 +276,7 @@ cleanup:
 
 int lg2_merge(git_repository *repo, int argc, char **argv)
 {
-	merge_options opts;
+	struct merge_options opts;
 	git_index *index;
 	git_repository_state_t state;
 	git_merge_analysis_t analysis;
diff --git a/examples/remote.c b/examples/remote.c
index 7345f82de..34d886526 100644
--- a/examples/remote.c
+++ b/examples/remote.c
@@ -30,7 +30,7 @@ enum subcmd {
 	subcmd_show,
 };
 
-struct opts {
+struct remote_opts {
 	enum subcmd cmd;
 
 	/* for command-specific args */
@@ -38,20 +38,20 @@ struct opts {
 	char **argv;
 };
 
-static int cmd_add(git_repository *repo, struct opts *o);
-static int cmd_remove(git_repository *repo, struct opts *o);
-static int cmd_rename(git_repository *repo, struct opts *o);
-static int cmd_seturl(git_repository *repo, struct opts *o);
-static int cmd_show(git_repository *repo, struct opts *o);
+static int cmd_add(git_repository *repo, struct remote_opts *o);
+static int cmd_remove(git_repository *repo, struct remote_opts *o);
+static int cmd_rename(git_repository *repo, struct remote_opts *o);
+static int cmd_seturl(git_repository *repo, struct remote_opts *o);
+static int cmd_show(git_repository *repo, struct remote_opts *o);
 
 static void parse_subcmd(
-	struct opts *opt, int argc, char **argv);
+	struct remote_opts *opt, int argc, char **argv);
 static void usage(const char *msg, const char *arg);
 
 int lg2_remote(git_repository *repo, int argc, char *argv[])
 {
 	int retval = 0;
-	struct opts opt = {0};
+	struct remote_opts opt = {0};
 
 	parse_subcmd(&opt, argc, argv);
 
@@ -77,7 +77,7 @@ int lg2_remote(git_repository *repo, int argc, char *argv[])
 	return retval;
 }
 
-static int cmd_add(git_repository *repo, struct opts *o)
+static int cmd_add(git_repository *repo, struct remote_opts *o)
 {
 	char *name, *url;
 	git_remote *remote = {0};
@@ -94,7 +94,7 @@ static int cmd_add(git_repository *repo, struct opts *o)
 	return 0;
 }
 
-static int cmd_remove(git_repository *repo, struct opts *o)
+static int cmd_remove(git_repository *repo, struct remote_opts *o)
 {
 	char *name;
 
@@ -109,7 +109,7 @@ static int cmd_remove(git_repository *repo, struct opts *o)
 	return 0;
 }
 
-static int cmd_rename(git_repository *repo, struct opts *o)
+static int cmd_rename(git_repository *repo, struct remote_opts *o)
 {
 	int i, retval;
 	char *old, *new;
@@ -134,7 +134,7 @@ static int cmd_rename(git_repository *repo, struct opts *o)
 	return retval;
 }
 
-static int cmd_seturl(git_repository *repo, struct opts *o)
+static int cmd_seturl(git_repository *repo, struct remote_opts *o)
 {
 	int i, retval, push = 0;
 	char *name = NULL, *url = NULL;
@@ -166,7 +166,7 @@ static int cmd_seturl(git_repository *repo, struct opts *o)
 	return 0;
 }
 
-static int cmd_show(git_repository *repo, struct opts *o)
+static int cmd_show(git_repository *repo, struct remote_opts *o)
 {
 	int i;
 	const char *arg, *name, *fetch, *push;
@@ -213,7 +213,7 @@ static int cmd_show(git_repository *repo, struct opts *o)
 }
 
 static void parse_subcmd(
-	struct opts *opt, int argc, char **argv)
+	struct remote_opts *opt, int argc, char **argv)
 {
 	char *arg = argv[1];
 	enum subcmd cmd = 0;
diff --git a/examples/rev-list.c b/examples/rev-list.c
index c366ecea2..75fb19e70 100644
--- a/examples/rev-list.c
+++ b/examples/rev-list.c
@@ -15,16 +15,24 @@
 
 #include "common.h"
 
-static int revwalk_parseopts(git_repository *repo, git_revwalk *walk, int nopts, char **opts);
+#include <assert.h>
+
+static int revwalk_parse_options(git_sort_t *sort, struct args_info *args);
+static int revwalk_parse_revs(git_repository *repo, git_revwalk *walk, struct args_info *args);
 
 int lg2_rev_list(git_repository *repo, int argc, char **argv)
 {
+	struct args_info args = ARGS_INFO_INIT;
 	git_revwalk *walk;
 	git_oid oid;
+	git_sort_t sort;
 	char buf[GIT_OID_HEXSZ+1];
 
+	check_lg2(revwalk_parse_options(&sort, &args), "parsing options", NULL);
+
 	check_lg2(git_revwalk_new(&walk, repo), "allocating revwalk", NULL);
-	check_lg2(revwalk_parseopts(repo, walk, argc-1, argv+1), "parsing options", NULL);
+	git_revwalk_sorting(walk, sort);
+	check_lg2(revwalk_parse_revs(repo, walk, &args), "parsing revs", NULL);
 
 	while (!git_revwalk_next(&oid, walk)) {
 		git_oid_fmt(buf, &oid);
@@ -32,6 +40,7 @@ int lg2_rev_list(git_repository *repo, int argc, char **argv)
 		printf("%s\n", buf);
 	}
 
+	git_revwalk_free(walk);
 	return 0;
 }
 
@@ -80,33 +89,60 @@ out:
 	return error;
 }
 
-static int revwalk_parseopts(git_repository *repo, git_revwalk *walk, int nopts, char **opts)
+static void print_usage(void)
+{
+	fprintf(stderr, "rev-list [--git-dir=dir] [--topo-order|--date-order] [--reverse] <revspec>\n");
+	exit(-1);
+}
+
+static int revwalk_parse_options(git_sort_t *sort, struct args_info *args)
 {
-	int hide, i, error;
-	unsigned int sorting = GIT_SORT_NONE;
+	assert(sort && args);
+	*sort = GIT_SORT_NONE;
+
+	if (args->argc < 1)
+		print_usage();
+
+	for (args->pos = 1; args->pos < args->argc; ++args->pos) {
+		const char *curr = args->argv[args->pos];
+
+		if (!strcmp(curr, "--topo-order")) {
+			*sort |= GIT_SORT_TOPOLOGICAL;
+		} else if (!strcmp(curr, "--date-order")) {
+			*sort |= GIT_SORT_TIME;
+		} else if (!strcmp(curr, "--reverse")) {
+			*sort |= (*sort & ~GIT_SORT_REVERSE) ^ GIT_SORT_REVERSE;
+		} else {
+			break;
+		}
+	}
+	return 0;
+}
+
+static int revwalk_parse_revs(git_repository *repo, git_revwalk *walk, struct args_info *args)
+{
+	int hide, error;
+	git_oid oid;
 
 	hide = 0;
-	for (i = 0; i < nopts; i++) {
-		if (!strcmp(opts[i], "--topo-order")) {
-			sorting = GIT_SORT_TOPOLOGICAL | (sorting & GIT_SORT_REVERSE);
-			git_revwalk_sorting(walk, sorting);
-		} else if (!strcmp(opts[i], "--date-order")) {
-			sorting = GIT_SORT_TIME | (sorting & GIT_SORT_REVERSE);
-			git_revwalk_sorting(walk, sorting);
-		} else if (!strcmp(opts[i], "--reverse")) {
-			sorting = (sorting & ~GIT_SORT_REVERSE)
-			    | ((sorting & GIT_SORT_REVERSE) ? 0 : GIT_SORT_REVERSE);
-			git_revwalk_sorting(walk, sorting);
-		} else if (!strcmp(opts[i], "--not")) {
+	for (; args->pos < args->argc; ++args->pos) {
+		const char *curr = args->argv[args->pos];
+
+		if (!strcmp(curr, "--not")) {
 			hide = !hide;
-		} else if (opts[i][0] == '^') {
-			if ((error = push_spec(repo, walk, opts[i] + 1, !hide)))
+		} else if (curr[0] == '^') {
+			if ((error = push_spec(repo, walk, curr + 1, !hide)))
 				return error;
-		} else if (strstr(opts[i], "..")) {
-			if ((error = push_range(repo, walk, opts[i], hide)))
+		} else if (strstr(curr, "..")) {
+			if ((error = push_range(repo, walk, curr, hide)))
 				return error;
 		} else {
-			if ((error = push_spec(repo, walk, opts[i], hide)))
+			if (push_spec(repo, walk, curr, hide) == 0)
+				continue;
+
+			if ((error = git_oid_fromstr(&oid, curr)))
+				return error;
+			if ((error = push_commit(walk, &oid, hide)))
 				return error;
 		}
 	}
diff --git a/examples/show-index.c b/examples/show-index.c
index 34eb41c7b..7aaa45e65 100644
--- a/examples/show-index.c
+++ b/examples/show-index.c
@@ -14,7 +14,7 @@
 
 #include "common.h"
 
-int lg2_show_index(git_repository *repo, int argc, char** argv)
+int lg2_show_index(git_repository *repo, int argc, char **argv)
 {
 	git_index *index;
 	size_t i, ecount;
diff --git a/examples/status.c b/examples/status.c
index 979ab7c97..8cf922127 100644
--- a/examples/status.c
+++ b/examples/status.c
@@ -43,7 +43,7 @@ enum {
 
 #define MAX_PATHSPEC 8
 
-struct opts {
+struct status_opts {
 	git_status_options statusopt;
 	char *repodir;
 	char *pathspec[MAX_PATHSPEC];
@@ -55,7 +55,7 @@ struct opts {
 	int repeat;
 };
 
-static void parse_opts(struct opts *o, int argc, char *argv[]);
+static void parse_opts(struct status_opts *o, int argc, char *argv[]);
 static void show_branch(git_repository *repo, int format);
 static void print_long(git_status_list *status);
 static void print_short(git_repository *repo, git_status_list *status);
@@ -64,7 +64,7 @@ static int print_submod(git_submodule *sm, const char *name, void *payload);
 int lg2_status(git_repository *repo, int argc, char *argv[])
 {
 	git_status_list *status;
-	struct opts o = { GIT_STATUS_OPTIONS_INIT, "." };
+	struct status_opts o = { GIT_STATUS_OPTIONS_INIT, "." };
 
 	o.statusopt.show  = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
 	o.statusopt.flags = GIT_STATUS_OPT_INCLUDE_UNTRACKED |
@@ -435,7 +435,7 @@ static int print_submod(git_submodule *sm, const char *name, void *payload)
 /**
  * Parse options that git's status command supports.
  */
-static void parse_opts(struct opts *o, int argc, char *argv[])
+static void parse_opts(struct status_opts *o, int argc, char *argv[])
 {
 	struct args_info args = ARGS_INFO_INIT;
 
diff --git a/examples/tag.c b/examples/tag.c
index 7bfb92a3e..440829419 100644
--- a/examples/tag.c
+++ b/examples/tag.c
@@ -31,19 +31,19 @@
  */
 
 /** tag_options represents the parsed command line options */
-typedef struct {
+struct tag_options {
 	const char *message;
 	const char *pattern;
 	const char *tag_name;
 	const char *target;
 	int num_lines;
 	int force;
-} tag_options;
+};
 
 /** tag_state represents the current program state for dragging around */
 typedef struct {
 	git_repository *repo;
-	tag_options *opts;
+	struct tag_options *opts;
 } tag_state;
 
 /** An action to execute based on the command line arguments */
@@ -167,7 +167,7 @@ static void action_list_tags(tag_state *state)
 
 static void action_delete_tag(tag_state *state)
 {
-	tag_options *opts = state->opts;
+	struct tag_options *opts = state->opts;
 	git_object *obj;
 	git_buf abbrev_oid = {0};
 
@@ -191,7 +191,7 @@ static void action_delete_tag(tag_state *state)
 static void action_create_lighweight_tag(tag_state *state)
 {
 	git_repository *repo = state->repo;
-	tag_options *opts = state->opts;
+	struct tag_options *opts = state->opts;
 	git_oid oid;
 	git_object *target;
 
@@ -213,7 +213,7 @@ static void action_create_lighweight_tag(tag_state *state)
 static void action_create_tag(tag_state *state)
 {
 	git_repository *repo = state->repo;
-	tag_options *opts = state->opts;
+	struct tag_options *opts = state->opts;
 	git_signature *tagger;
 	git_oid oid;
 	git_object *target;
@@ -243,7 +243,7 @@ static void print_usage(void)
 }
 
 /** Parse command line arguments and choose action to run when done */
-static void parse_options(tag_action *action, tag_options *opts, int argc, char **argv)
+static void parse_options(tag_action *action, struct tag_options *opts, int argc, char **argv)
 {
 	args_info args = ARGS_INFO_INIT;
 	*action = &action_list_tags;
@@ -281,7 +281,7 @@ static void parse_options(tag_action *action, tag_options *opts, int argc, char
 }
 
 /** Initialize tag_options struct */
-static void tag_options_init(tag_options *opts)
+static void tag_options_init(struct tag_options *opts)
 {
 	memset(opts, 0, sizeof(*opts));
 
@@ -295,7 +295,7 @@ static void tag_options_init(tag_options *opts)
 
 int lg2_tag(git_repository *repo, int argc, char **argv)
 {
-	tag_options opts;
+	struct tag_options opts;
 	tag_action action;
 	tag_state state;