examples: add remote example.

examples/.gitignore

@@ -7,6 +7,7 @@ cat-file
 init
 log
 rev-parse
+remote
 status
 tag
 for-each-ref

examples/Makefile

@@ -3,7 +3,7 @@
 CC = gcc
 CFLAGS = -g -I../include -I../src -Wall -Wextra -Wmissing-prototypes -Wno-missing-field-initializers
 LFLAGS = -L../build -lgit2 -lz
-APPS = general showindex diff rev-list cat-file status log rev-parse init blame tag
+APPS = general showindex diff rev-list cat-file status log rev-parse init blame tag remote
 APPS += for-each-ref
 
 all: $(APPS)

examples/remote.c

+/*
+ * libgit2 "remote" example - shows how to modify remotes for a repo
+ *
+ * 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/>.
+ */
+
+#include "common.h"
+
+/**
+ * This is a sample program that is similar to "git remote".  See the
+ * documentation for that (try "git help remote") to understand what this
+ * program is emulating.
+ *
+ * This demonstrates using the libgit2 APIs to modify remotes of a repository.
+ */
+
+enum subcmd {
+	subcmd_add,
+	subcmd_remove,
+	subcmd_rename,
+	subcmd_seturl,
+	subcmd_show,
+};
+
+struct opts {
+	enum subcmd cmd;
+
+	/* for command-specific args */
+	int argc;
+	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 void parse_subcmd(
+	struct opts *opt, int argc, char **argv);
+static void usage(const char *msg, const char *arg);
+
+int main(int argc, char *argv[])
+{
+	int retval = 0;
+	struct opts opt = {0};
+	git_buf buf = GIT_BUF_INIT_CONST(NULL, 0);
+	git_repository *repo = NULL;
+
+	parse_subcmd(&opt, argc, argv);
+
+	git_libgit2_init();
+
+	check_lg2(git_repository_discover(&buf, ".", 0, NULL),
+		"Could not find repository", NULL);
+
+	check_lg2(git_repository_open(&repo, buf.ptr),
+		"Could not open repository", NULL);
+	git_buf_free(&buf);
+
+	switch (opt.cmd)
+	{
+	case subcmd_add:
+		retval = cmd_add(repo, &opt);
+		break;
+	case subcmd_remove:
+		retval = cmd_remove(repo, &opt);
+		break;
+	case subcmd_rename:
+		retval = cmd_rename(repo, &opt);
+		break;
+	case subcmd_seturl:
+		retval = cmd_seturl(repo, &opt);
+		break;
+	case subcmd_show:
+		retval = cmd_show(repo, &opt);
+		break;
+	}
+
+	git_libgit2_shutdown();
+
+	return retval;
+}
+
+static int cmd_add(git_repository *repo, struct opts *o)
+{
+	char *name, *url;
+	git_remote *remote = {0};
+
+	if (o->argc != 2)
+		usage("you need to specify a name and URL", NULL);
+
+	name = o->argv[0];
+	url = o->argv[1];
+
+	check_lg2(git_remote_create(&remote, repo, name, url),
+			"could not create remote", NULL);
+
+	return 0;
+}
+
+static int cmd_remove(git_repository *repo, struct opts *o)
+{
+	char *name;
+
+	if (o->argc != 1)
+		usage("you need to specify a name", NULL);
+
+	name = o->argv[0];
+
+	check_lg2(git_remote_delete(repo, name),
+			"could not delete remote", name);
+
+	return 0;
+}
+
+static int cmd_rename(git_repository *repo, struct opts *o)
+{
+	int i, retval;
+	char *old, *new;
+	git_strarray problems = {0};
+
+	if (o->argc != 2)
+		usage("you need to specify old and new remote name", NULL);
+
+	old = o->argv[0];
+	new = o->argv[1];
+
+	retval = git_remote_rename(&problems, repo, old, new);
+	if (!retval)
+		return 0;
+
+	for (i = 0; i < (int) problems.count; i++) {
+		puts(problems.strings[0]);
+	}
+
+	git_strarray_free(&problems);
+
+	return retval;
+}
+
+static int cmd_seturl(git_repository *repo, struct opts *o)
+{
+	int i, retval, push = 0;
+	char *name = NULL, *url = NULL;
+	git_remote *remote;
+
+	for (i = 0; i < o->argc; i++) {
+		char *arg = o->argv[i];
+
+		if (!strcmp(arg, "--push")) {
+			push = 1;
+		} else if (arg[0] != '-' && name == NULL) {
+			name = arg;
+		} else if (arg[0] != '-' && url == NULL) {
+			url = arg;
+		} else {
+			usage("invalid argument to set-url", arg);
+		}
+	}
+
+	if (name == NULL || url == NULL)
+		usage("you need to specify remote and the new URL", NULL);
+
+	check_lg2(git_remote_lookup(&remote, repo, name),
+			"could not look up remote", name);
+
+	if (push)
+		retval = git_remote_set_pushurl(remote, url);
+	else
+		retval = git_remote_set_url(remote, url);
+	check_lg2(retval, "could not set URL", url);
+
+	check_lg2(git_remote_save(remote),
+			"could not save remote", NULL);
+
+	git_remote_free(remote);
+
+	return 0;
+}
+
+static int cmd_show(git_repository *repo, struct opts *o)
+{
+	int i;
+	const char *arg, *name, *fetch, *push;
+	int verbose = 0;
+	git_strarray remotes = {0};
+	git_remote *remote = {0};
+
+	for (i = 0; i < o->argc; i++) {
+		arg = o->argv[i];
+
+		if (!strcmp(arg, "-v") || !strcmp(arg, "--verbose")) {
+			verbose = 1;
+		}
+	}
+
+	check_lg2(git_remote_list(&remotes, repo),
+		"could not retrieve remotes", NULL);
+
+	for (i = 0; i < (int) remotes.count; i++) {
+		name = remotes.strings[i];
+		if (!verbose) {
+			puts(name);
+			continue;
+		}
+
+		check_lg2(git_remote_lookup(&remote, repo, name),
+			"could not look up remote", name);
+
+		fetch = git_remote_url(remote);
+		if (fetch)
+			printf("%s\t%s (fetch)\n", name, fetch);
+		push = git_remote_pushurl(remote);
+		/* use fetch URL if no distinct push URL has been set */
+		push = push ? push : fetch;
+		if (push)
+			printf("%s\t%s (push)\n", name, push);
+
+		git_remote_free(remote);
+	}
+
+	git_strarray_free(&remotes);
+
+	return 0;
+}
+
+static void parse_subcmd(
+	struct opts *opt, int argc, char **argv)
+{
+	char *arg = argv[1];
+	enum subcmd cmd = 0;
+
+	if (argc < 2)
+		usage("no command specified", NULL);
+
+	if (!strcmp(arg, "add")) {
+		cmd = subcmd_add;
+	} else if (!strcmp(arg, "remove")) {
+		cmd = subcmd_remove;
+	} else if (!strcmp(arg, "rename")) {
+		cmd = subcmd_rename;
+	} else if (!strcmp(arg, "set-url")) {
+		cmd = subcmd_seturl;
+	} else if (!strcmp(arg, "show")) {
+		cmd = subcmd_show;
+	} else {
+		usage("command is not valid", arg);
+	}
+	opt->cmd = cmd;
+
+	opt->argc = argc - 2; /* executable and subcommand are removed */
+	opt->argv = argv + 2;
+}
+
+static void usage(const char *msg, const char *arg)
+{
+	fputs("usage: remote add <name> <url>\n", stderr);
+	fputs("       remote remove <name>\n", stderr);
+	fputs("       remote rename <old> <new>\n", stderr);
+	fputs("       remote set-url [--push] <name> <newurl>\n", stderr);
+	fputs("       remote show [-v|--verbose]\n", stderr);
+
+	if (msg && !arg)
+		fprintf(stderr, "\n%s\n", msg);
+	else if (msg && arg)
+		fprintf(stderr, "\n%s: %s\n", msg, arg);
+	exit(1);
+}