cli: add `config` command

Add a `config` command with `--list` and `--get`.

src/cli/cmd.h

@@ -27,6 +27,7 @@ extern const cli_cmd_spec *cli_cmd_spec_byname(const char *name);
 /* Commands */
 extern int cmd_cat_file(int argc, char **argv);
 extern int cmd_clone(int argc, char **argv);
+extern int cmd_config(int argc, char **argv);
 extern int cmd_hash_object(int argc, char **argv);
 extern int cmd_help(int argc, char **argv);
 

src/cli/cmd_config.c

+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include <git2.h>
+#include "cli.h"
+#include "cmd.h"
+
+#define COMMAND_NAME "config"
+
+typedef enum {
+	ACTION_NONE = 0,
+	ACTION_GET,
+	ACTION_LIST
+} action_t;
+
+static action_t action = ACTION_NONE;
+static int show_origin;
+static int show_scope;
+static int show_help;
+static int null_separator;
+static char *name;
+
+static const cli_opt_spec opts[] = {
+	{ CLI_OPT_TYPE_SWITCH,    "help",    0, &show_help,   1,
+	  CLI_OPT_USAGE_HIDDEN | CLI_OPT_USAGE_STOP_PARSING, NULL,
+	  "display help about the " COMMAND_NAME " command" },
+
+	{ CLI_OPT_TYPE_SWITCH,    "null",        'z', &null_separator, 1,
+	  0,                       NULL,         "use NUL as a separator" },
+
+	{ CLI_OPT_TYPE_SWITCH,    "get",          0,  &action,     ACTION_GET,
+	  CLI_OPT_USAGE_REQUIRED,  NULL,         "get a configuration value" },
+	{ CLI_OPT_TYPE_SWITCH,    "list",        'l', &action,     ACTION_LIST,
+	  CLI_OPT_USAGE_CHOICE | CLI_OPT_USAGE_SHOW_LONG,
+	                           NULL,         "list all configuration entries" },
+	{ CLI_OPT_TYPE_SWITCH,    "show-origin",  0,  &show_origin, 1,
+	  0,                       NULL,         "show origin of configuration" },
+	{ CLI_OPT_TYPE_SWITCH,    "show-scope",   0,  &show_scope,  1,
+	  0,                       NULL,         "show scope of configuration" },
+	{ CLI_OPT_TYPE_ARG,       "name",         0,  &name,        0,
+	  0,                      "name",        "name of configuration entry" },
+	{ 0 },
+};
+
+static void print_help(void)
+{
+	cli_opt_usage_fprint(stdout, PROGRAM_NAME, COMMAND_NAME, opts);
+	printf("\n");
+
+	printf("Query and set configuration options.\n");
+	printf("\n");
+
+	printf("Options:\n");
+
+	cli_opt_help_fprint(stdout, opts);
+}
+
+static int get_config(git_config *config)
+{
+	git_buf value = GIT_BUF_INIT;
+	char sep = null_separator ? '\0' : '\n';
+	int error;
+
+	error = git_config_get_string_buf(&value, config, name);
+
+	if (error && error != GIT_ENOTFOUND)
+		return cli_error_git();
+
+	else if (error == GIT_ENOTFOUND)
+		return 1;
+
+	printf("%s%c", value.ptr, sep);
+	return 0;
+}
+
+static const char *level_name(git_config_level_t level)
+{
+	switch (level) {
+	case GIT_CONFIG_LEVEL_PROGRAMDATA:
+		return "programdata";
+	case GIT_CONFIG_LEVEL_SYSTEM:
+		return "system";
+	case GIT_CONFIG_LEVEL_XDG:
+		return "global";
+	case GIT_CONFIG_LEVEL_GLOBAL:
+		return "global";
+	case GIT_CONFIG_LEVEL_LOCAL:
+		return "local";
+	case GIT_CONFIG_LEVEL_APP:
+		return "command";
+	default:
+		return "unknown";
+	}
+}
+
+static int list_config(git_config *config)
+{
+	git_config_iterator *iterator;
+	git_config_entry *entry;
+	char data_separator = null_separator ? '\0' : '\t';
+	char kv_separator = null_separator ? '\n' : '=';
+	char entry_separator = null_separator ? '\0' : '\n';
+	int error;
+
+	if (git_config_iterator_new(&iterator, config) < 0)
+		return cli_error_git();
+
+	while ((error = git_config_next(&entry, iterator)) == 0) {
+		if (show_scope)
+			printf("%s%c",
+				level_name(entry->level),
+				data_separator);
+
+		if (show_origin)
+			printf("%s%s%s%c",
+				entry->backend_type ? entry->backend_type : "",
+				entry->backend_type && entry->origin_path ? ":" : "",
+				entry->origin_path ? entry->origin_path : "",
+				data_separator);
+
+		printf("%s%c%s%c", entry->name, kv_separator, entry->value,
+			entry_separator);
+	}
+
+	if (error != GIT_ITEROVER)
+		return cli_error_git();
+
+	git_config_iterator_free(iterator);
+	return 0;
+}
+
+int cmd_config(int argc, char **argv)
+{
+	git_repository *repo = NULL;
+	git_config *config = NULL;
+	cli_opt invalid_opt;
+	int ret = 0;
+
+	if (cli_opt_parse(&invalid_opt, opts, argv + 1, argc - 1, CLI_OPT_PARSE_GNU))
+		return cli_opt_usage_error(COMMAND_NAME, opts, &invalid_opt);
+
+	if (show_help) {
+		print_help();
+		return 0;
+	}
+
+	if (git_repository_open_ext(&repo, ".", GIT_REPOSITORY_OPEN_FROM_ENV, NULL) < 0 ||
+	    git_repository_config(&config, repo) < 0) {
+		ret = cli_error_git();
+		goto done;
+	}
+
+	switch (action) {
+	case ACTION_LIST:
+		if (name)
+			ret = cli_error_usage("%s --list does not take an argument", COMMAND_NAME);
+		else
+			ret = list_config(config);
+		break;
+	case ACTION_GET:
+		if (!name)
+			ret = cli_error_usage("%s --get requires an argument", COMMAND_NAME);
+		else
+			ret = get_config(config);
+		break;
+	default:
+		ret = cli_error_usage("unknown action");
+	}
+
+done:
+	git_config_free(config);
+	git_repository_free(repo);
+	return ret;
+}

src/cli/main.c

@@ -30,6 +30,7 @@ const cli_opt_spec cli_common_opts[] = {
 const cli_cmd_spec cli_cmds[] = {
 	{ "cat-file",    cmd_cat_file,    "Display an object in the repository" },
 	{ "clone",       cmd_clone,       "Clone a repository into a new directory" },
+	{ "config",      cmd_config,      "View or set configuration values " },
 	{ "hash-object", cmd_hash_object, "Hash a raw object and product its object ID" },
 	{ "help",        cmd_help,        "Display help information" },
 	{ NULL }