[PATCH v6] var: support broken-down idents, signing key, multiple args, and -z

@@ -9,12 +9,16 @@ git-var - Show a Git logical variable
 SYNOPSIS
 --------
 [synopsis]
-git var (-l | <variable>)
+git var [-z] -l
+git var [-z] <variable>...
 
 DESCRIPTION
 -----------
-Prints a Git logical variable. Exits with code 1 if the variable has
-no value.
+Prints Git logical variables. Exits with code 1 if any requested
+variable has no value. When multiple variables are requested, an empty
+record (a blank line, or an empty NUL-terminated record when `-z` is given)
+is printed for any variable that has no value, and the command continues
+processing the remaining variables.
 
 OPTIONS
 -------

@@ -24,19 +28,65 @@ OPTIONS
 	as well. (However, the configuration variables listing functionality
 	is deprecated in favor of `git config list`.)
 
+`-z`::
+	Terminate entries with NUL instead of newline. When used with
+	`-l`, the variable name and its value are separated by a newline,
+	and each entry is terminated with a NUL byte.
+
 EXAMPLES
 --------
-	$ git var GIT_AUTHOR_IDENT
-	Eric W. Biederman <ebiederm@lnxi.com> 1121223278 -0600
-
+* Get the author identity:
++
+------------
+$ git var GIT_AUTHOR_IDENT
+Eric W. Biederman <ebiederm@lnxi.com> 1121223278 -0600
+------------
+
+* Get the author name and email:
++
+------------
+$ git var GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL
+Eric W. Biederman
+ebiederm@lnxi.com
+------------
 
 VARIABLES
 ---------
 `GIT_AUTHOR_IDENT`::
-    The author of a piece of code.
+    The author name, email, and date that would be used if you were to
+    run `git commit` right now.
+
+`GIT_AUTHOR_NAME`::
+    The author name that would be used if you were to run `git commit`
+    right now.
+
+`GIT_AUTHOR_EMAIL`::
+    The author email that would be used if you were to run `git commit`
+    right now.
+
+`GIT_AUTHOR_DATE`::
+    The author date and timezone that would be used if you were to run
+    `git commit` right now.
 
 `GIT_COMMITTER_IDENT`::
-    The person who put a piece of code into Git.
+    The committer name, email, and date that would be used if you were
+    to run `git commit` right now.
+
+`GIT_COMMITTER_NAME`::
+    The name of the committer that would be used if you were to run
+    `git commit` right now.
+
+`GIT_COMMITTER_EMAIL`::
+    The email of the committer that would be used if you were to run
+    `git commit` right now.
+
+`GIT_COMMITTER_DATE`::
+    The committer date and timezone that would be used if you were to run
+    `git commit` right now.
+
+`GIT_SIGNING_KEY`::
+    The key that would be used to sign the resulting commit if you were
+    to run `git commit` right now.
 
 `GIT_EDITOR`::
     Text editor for use by Git commands.  The value is meant to be

@@ -85,9 +135,13 @@ endif::git-default-pager[]
     The path to the global (per-user) configuration files, if any.
 
 Most path values contain only one value. However, some can contain multiple
-values, which are separated by newlines, and are listed in order from highest to
-lowest priority.  Callers should be prepared for any such path value to contain
-multiple items.
+values, which are separated by newlines (or NUL bytes if `-z` is given),
+and are listed in order from highest to lowest priority. When querying
+multiple variables, an extra newline (or an extra NUL byte if `-z` is
+given) is printed after the values of a multi-valued variable to mark the
+end of its list. (Single-variable queries and `git var -l` do not print
+an extra delimiter). Callers should be prepared for any such path value to
+contain multiple items.
 
 Note that paths are printed even if they do not exist, but not if they are
 disabled by other environment variables.

@@ -12,25 +12,112 @@
 #include "config.h"
 #include "editor.h"
 #include "environment.h"
+#include "gpg-interface.h"
 #include "ident.h"
 #include "pager.h"
-#include "refs.h"
+#include "parse-options.h"
 #include "path.h"
-#include "strbuf.h"
+#include "refs.h"
 #include "run-command.h"
+#include "strbuf.h"
+#include "string-list.h"
+
+static const char * const var_usage[] = {
+	N_("git var [-z] -l"),
+	N_("git var [-z] <variable>..."),
+	NULL
+};
 
-static const char var_usage[] = "git var (-l | <variable>)";
+enum ident_part {
+	IDENT_NAME,
+	IDENT_MAIL,
+	IDENT_DATE,
+};
 
 static char *committer(int ident_flag)
 {
 	return xstrdup_or_null(git_committer_info(ident_flag));
 }
 
+static char *ident_part(const char *ident, enum ident_part part)
+{
+	struct ident_split split;
+
+	if (!ident)
+		return NULL;
+	if (split_ident_line(&split, ident, strlen(ident)))
+		return NULL;
+
+	switch (part) {
+	case IDENT_NAME:
+		return xmemdupz(split.name_begin,
+				split.name_end - split.name_begin);
+	case IDENT_MAIL:
+		return xmemdupz(split.mail_begin,
+				split.mail_end - split.mail_begin);
+	case IDENT_DATE:
+		if (!split.date_begin)
+			return NULL;
+		if (split.tz_end)
+			return xmemdupz(split.date_begin,
+					split.tz_end -
+					split.date_begin);
+		if (split.date_end)
+			return xmemdupz(split.date_begin,
+					split.date_end -
+					split.date_begin);
+		return NULL;
+	default:
+		BUG("unknown ident_part %d", part);
+	}
+}
+
+static char *committer_name(int ident_flag)
+{
+	return ident_part(git_committer_info(ident_flag), IDENT_NAME);
+}
+
+static char *committer_email(int ident_flag)
+{
+	return ident_part(git_committer_info(ident_flag), IDENT_MAIL);
+}
+
+static char *committer_date(int ident_flag)
+{
+	return ident_part(git_committer_info(ident_flag), IDENT_DATE);
+}
+
 static char *author(int ident_flag)
 {
 	return xstrdup_or_null(git_author_info(ident_flag));
 }
 
+static char *author_name(int ident_flag)
+{
+	return ident_part(git_author_info(ident_flag), IDENT_NAME);
+}
+
+static char *author_email(int ident_flag)
+{
+	return ident_part(git_author_info(ident_flag), IDENT_MAIL);
+}
+
+static char *author_date(int ident_flag)
+{
+	return ident_part(git_author_info(ident_flag), IDENT_DATE);
+}
+
+static char *git_signing_key(int ident_flag UNUSED)
+{
+	char *signing_key = get_signing_key();
+
+	if (signing_key && !*signing_key) {
+		free(signing_key);
+		return NULL;
+	}
+	return signing_key;
+}
+
 static char *editor(int ident_flag UNUSED)
 {
 	return xstrdup_or_null(git_editor());

@@ -90,45 +177,62 @@ static char *git_config_val_system(int ident_flag UNUSED)
 	return NULL;
 }
 
-static char *git_config_val_global(int ident_flag UNUSED)
+static int git_config_val_global(struct string_list *list)
 {
-	struct strbuf buf = STRBUF_INIT;
 	char *user, *xdg;
-	size_t unused;
 
 	git_global_config_paths(&user, &xdg);
 	if (xdg && *xdg) {
 		normalize_path_copy(xdg, xdg);
-		strbuf_addf(&buf, "%s\n", xdg);
+		string_list_append(list, xdg);
 	}
 	if (user && *user) {
 		normalize_path_copy(user, user);
-		strbuf_addf(&buf, "%s\n", user);
+		string_list_append(list, user);
 	}
 	free(xdg);
 	free(user);
-	strbuf_trim_trailing_newline(&buf);
-	if (buf.len == 0) {
-		strbuf_release(&buf);
-		return NULL;
-	}
-	return strbuf_detach(&buf, &unused);
+	return !list->nr;
 }
 
 struct git_var {
 	const char *name;
 	char *(*read)(int);
-	int multivalued;
+	int (*multiread)(struct string_list *);
 };
 static struct git_var git_vars[] = {
 	{
 		.name = "GIT_COMMITTER_IDENT",
 		.read = committer,
 	},
+	{
+		.name = "GIT_COMMITTER_NAME",
+		.read = committer_name,
+	},
+	{
+		.name = "GIT_COMMITTER_EMAIL",
+		.read = committer_email,
+	},
+	{
+		.name = "GIT_COMMITTER_DATE",
+		.read = committer_date,
+	},
 	{
 		.name = "GIT_AUTHOR_IDENT",
 		.read = author,
 	},
+	{
+		.name = "GIT_AUTHOR_NAME",
+		.read = author_name,
+	},
+	{
+		.name = "GIT_AUTHOR_EMAIL",
+		.read = author_email,
+	},
+	{
+		.name = "GIT_AUTHOR_DATE",
+		.read = author_date,
+	},
 	{
 		.name = "GIT_EDITOR",
 		.read = editor,

@@ -145,6 +249,10 @@ static struct git_var git_vars[] = {
 		.name = "GIT_DEFAULT_BRANCH",
 		.read = default_branch,
 	},
+	{
+		.name = "GIT_SIGNING_KEY",
+		.read = git_signing_key,
+	},
 	{
 		.name = "GIT_SHELL_PATH",
 		.read = shell_path,

@@ -163,8 +271,7 @@ static struct git_var git_vars[] = {
 	},
 	{
 		.name = "GIT_CONFIG_GLOBAL",
-		.read = git_config_val_global,
-		.multivalued = 1,
+		.multiread = git_config_val_global,
 	},
 	{
 		.name = "",

@@ -172,31 +279,38 @@ static struct git_var git_vars[] = {
 	},
 };
 
-static void list_vars(void)
+static void list_vars(int nul_term)
 {
 	struct git_var *ptr;
-	char *val;
+	char delim = nul_term ? '\n' : '=';
+	char term = nul_term ? '\0' : '\n';
 
-	for (ptr = git_vars; ptr->read; ptr++)
-		if ((val = ptr->read(0))) {
-			if (ptr->multivalued && *val) {
-				struct string_list list = STRING_LIST_INIT_DUP;
+	for (ptr = git_vars; ptr->read || ptr->multiread; ptr++) {
+		if (ptr->read) {
+			char *val = ptr->read(0);
 
-				string_list_split(&list, val, "\n", -1);
-				for (size_t i = 0; i < list.nr; i++)
-					printf("%s=%s\n", ptr->name, list.items[i].string);
-				string_list_clear(&list, 0);
-			} else {
-				printf("%s=%s\n", ptr->name, val);
+			if (val) {
+				printf("%s%c%s%c", ptr->name, delim, val, term);
+				free(val);
 			}
-			free(val);
+		} else if (ptr->multiread) {
+			struct string_list list = STRING_LIST_INIT_DUP;
+			size_t i;
+
+			if (!ptr->multiread(&list)) {
+				for (i = 0; i < list.nr; i++)
+					printf("%s%c%s%c", ptr->name, delim,
+					       list.items[i].string, term);
+			}
+			string_list_clear(&list, 0);
 		}
+	}
 }
 
 static const struct git_var *get_git_var(const char *var)
 {
 	struct git_var *ptr;
-	for (ptr = git_vars; ptr->read; ptr++) {
+	for (ptr = git_vars; ptr->read || ptr->multiread; ptr++) {
 		if (strcmp(var, ptr->name) == 0) {
 			return ptr;
 		}

@@ -207,42 +321,91 @@ static const struct git_var *get_git_var(const char *var)
 static int show_config(const char *var, const char *value,
 		       const struct config_context *ctx, void *cb)
 {
+	int *nul_term = cb;
+	char delim = *nul_term ? '\n' : '=';
+	char term = *nul_term ? '\0' : '\n';
+
 	if (value)
-		printf("%s=%s\n", var, value);
+		printf("%s%c%s%c", var, delim, value, term);
 	else
-		printf("%s\n", var);
+		printf("%s%c", var, term);
 	return git_default_config(var, value, ctx, cb);
 }
 
 int cmd_var(int argc,
 	    const char **argv,
-	    const char *prefix UNUSED,
+	    const char *prefix,
 	    struct repository *repo UNUSED)
 {
-	const struct git_var *git_var;
-	char *val;
+	int list = 0;
+	int nul_term = 0;
+	int ret = 0;
+	int i;
+	char term;
+	struct option options[] = {
+		OPT_BOOL('l', NULL, &list,
+			 N_("list all variables")),
+		OPT_BOOL('z', NULL, &nul_term,
+			 N_("terminate entries with NUL")),
+		OPT_END(),
+	};
 
-	show_usage_if_asked(argc, argv, var_usage);
-	if (argc != 2)
-		usage(var_usage);
+	argc = parse_options(argc, argv, prefix, options,
+			     var_usage, PARSE_OPT_STOP_AT_NON_OPTION);
 
-	if (strcmp(argv[1], "-l") == 0) {
-		repo_config(the_repository, show_config, NULL);
-		list_vars();
+	if (list) {
+		if (argc)
+			usage_with_options(var_usage, options);
+		repo_config(the_repository, show_config, &nul_term);
+		list_vars(nul_term);
 		return 0;
 	}
+
+	if (!argc)
+		usage_with_options(var_usage, options);
+
 	repo_config(the_repository, git_default_config, NULL);
 
-	git_var = get_git_var(argv[1]);
-	if (!git_var)
-		usage(var_usage);
+	term = nul_term ? '\0' : '\n';
 
-	val = git_var->read(IDENT_STRICT);
-	if (!val)
-		return 1;
+	for (i = 0; i < argc; i++) {
+		const struct git_var *git_var = get_git_var(argv[i]);
 
-	printf("%s\n", val);
-	free(val);
+		if (!git_var)
+			usage_with_options(var_usage, options);
+
+		if (git_var->read) {
+			char *val = git_var->read(IDENT_STRICT);
+
+			if (!val) {
+				if (argc == 1)
+					return 1;
+				ret = 1;
+				printf("%c", term);
+				continue;
+			}
+			printf("%s%c", val, term);
+			free(val);
+		} else if (git_var->multiread) {
+			struct string_list list = STRING_LIST_INIT_DUP;
+			size_t j;
+
+			if (git_var->multiread(&list) || !list.nr) {
+				if (argc == 1) {
+					string_list_clear(&list, 0);
+					return 1;
+				}
+				ret = 1;
+				printf("%c", term);
+			} else {
+				for (j = 0; j < list.nr; j++)
+					printf("%s%c", list.items[j].string, term);
+				if (argc > 1)
+					printf("%c", term);
+			}
+			string_list_clear(&list, 0);
+		}
+	}
 
-	return 0;
+	return ret;
 }

@@ -276,4 +276,127 @@ test_expect_success '`git var -l` works even without HOME' '
 	)
 '
 
+test_expect_success 'get author identity components' '
+	test_tick &&
+	echo "$GIT_AUTHOR_NAME" >expect.name &&
+	echo "$GIT_AUTHOR_EMAIL" >expect.email &&
+	echo "$GIT_AUTHOR_DATE" >expect.date &&
+	git var GIT_AUTHOR_NAME >actual.name &&
+	git var GIT_AUTHOR_EMAIL >actual.email &&
+	git var GIT_AUTHOR_DATE >actual.date &&
+	test_cmp expect.name actual.name &&
+	test_cmp expect.email actual.email &&
+	test_cmp expect.date actual.date
+'
+
+test_expect_success 'get committer identity components' '
+	test_tick &&
+	echo "$GIT_COMMITTER_NAME" >expect.name &&
+	echo "$GIT_COMMITTER_EMAIL" >expect.email &&
+	echo "$GIT_COMMITTER_DATE" >expect.date &&
+	git var GIT_COMMITTER_NAME >actual.name &&
+	git var GIT_COMMITTER_EMAIL >actual.email &&
+	git var GIT_COMMITTER_DATE >actual.date &&
+	test_cmp expect.name actual.name &&
+	test_cmp expect.email actual.email &&
+	test_cmp expect.date actual.date
+'
+
+test_expect_success 'get multiple variables' '
+	test_tick &&
+	cat >expect <<-EOF &&
+	$GIT_AUTHOR_NAME
+	$GIT_AUTHOR_EMAIL
+	$GIT_COMMITTER_NAME
+	$GIT_COMMITTER_EMAIL
+	EOF
+	git var GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL GIT_COMMITTER_NAME GIT_COMMITTER_EMAIL >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'get multiple variables with -z' '
+	test_tick &&
+	printf "%s\0" "$GIT_AUTHOR_NAME" "$GIT_AUTHOR_EMAIL" >expect &&
+	git var -z GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'get multi-valued variable with -z' '
+	TRASHDIR="$(test-tool path-utils normalize_path_copy "$(pwd)")" &&
+	HOME="$TRASHDIR" XDG_CONFIG_HOME="$TRASHDIR/foo" git var -z GIT_CONFIG_GLOBAL >actual &&
+	printf "%s\0" "$TRASHDIR/foo/git/config" "$TRASHDIR/.gitconfig" >expected &&
+	test_cmp expected actual
+'
+
+test_expect_success 'git var -l -z' '
+	git var -l -z >actual &&
+	tr "\0" "\n" <actual >actual.lines &&
+	echo "$GIT_AUTHOR_NAME" >expect &&
+	sed -n "/^GIT_AUTHOR_NAME$/{n;p;}" actual.lines >actual.author &&
+	test_cmp expect actual.author &&
+	echo false >expect &&
+	sed -n "/^core\.bare$/{n;p;}" actual.lines >actual.bare &&
+	test_cmp expect actual.bare
+'
+
+test_expect_success 'get GIT_SIGNING_KEY with user.signingkey configured' '
+	test_config user.signingkey "TEST_KEY_ID" &&
+	echo "TEST_KEY_ID" >expect &&
+	git var GIT_SIGNING_KEY >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'get GIT_SIGNING_KEY fails when unset' '
+	test_config user.signingkey "" &&
+	test_must_fail git var GIT_SIGNING_KEY
+'
+
+test_expect_success 'git var -l lists new variables' '
+	git var -l >actual &&
+	test_grep "^GIT_AUTHOR_NAME=" actual &&
+	test_grep "^GIT_AUTHOR_EMAIL=" actual &&
+	test_grep "^GIT_AUTHOR_DATE=" actual &&
+	test_grep "^GIT_COMMITTER_NAME=" actual &&
+	test_grep "^GIT_COMMITTER_EMAIL=" actual &&
+	test_grep "^GIT_COMMITTER_DATE=" actual
+'
+
+test_expect_success 'git var -l lists GIT_SIGNING_KEY when configured' '
+	test_config user.signingkey "TEST_KEY_ID" &&
+	git var -l >actual &&
+	test_grep "^GIT_SIGNING_KEY=TEST_KEY_ID" actual
+'
+
+test_expect_success 'options must precede variable arguments' '
+	test_must_fail git var GIT_AUTHOR_NAME -z
+'
+
+test_expect_success 'get multiple variables with unset variable outputs blank record' '
+	test_config user.signingkey "" &&
+	cat >expect <<-EOF &&
+	$GIT_AUTHOR_NAME
+
+	$GIT_COMMITTER_NAME
+	EOF
+	test_must_fail git var GIT_AUTHOR_NAME GIT_SIGNING_KEY GIT_COMMITTER_NAME >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'get multiple variables with -z and unset variable' '
+	test_config user.signingkey "" &&
+	printf "%s\0\0%s\0" "$GIT_AUTHOR_NAME" "$GIT_COMMITTER_NAME" >expect &&
+	test_must_fail git var -z GIT_AUTHOR_NAME GIT_SIGNING_KEY GIT_COMMITTER_NAME >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'get multiple variables including multi-valued variable with -z' '
+	TRASHDIR="$(test-tool path-utils normalize_path_copy "$(pwd)")" &&
+	printf "%s\0%s\0%s\0\0%s\0" "$GIT_AUTHOR_NAME" \
+		"$TRASHDIR/foo/git/config" "$TRASHDIR/.gitconfig" \
+		"$GIT_AUTHOR_EMAIL" >expect &&
+	HOME="$TRASHDIR" XDG_CONFIG_HOME="$TRASHDIR/foo" \
+		git var -z GIT_AUTHOR_NAME GIT_CONFIG_GLOBAL GIT_AUTHOR_EMAIL >actual &&
+	test_cmp expect actual
+'
+
 test_done