sysctl: convert to VERB_COMMAND and add --introspect-cli

The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. An explicit "Commands" option group is added
so that the section heading stays the same. The abstract is changed to the
imperative. --help now goes through the pager, like other commands with
--no-pager.

src/sysctl/sysctl.c

@@ -1,26 +1,26 @@
 /* SPDX-License-Identifier: LGPL-2.1-or-later */
 
-#include <stdio.h>
 #include <sys/stat.h>
 
+#include "sd-json.h"
+
 #include "alloc-util.h"
 #include "build.h"
 #include "conf-files.h"
 #include "constants.h"
 #include "creds-util.h"
 #include "errno-util.h"
-#include "format-table.h"
 #include "glob-util.h"
 #include "hashmap.h"
 #include "log.h"
 #include "main-func.h"
-#include "options.h"
 #include "pager.h"
 #include "path-util.h"
 #include "pretty-print.h"
 #include "string-util.h"
 #include "strv.h"
 #include "sysctl-util.h"
+#include "verbs.h"
 
 static char **arg_prefixes = NULL;
 static CatFlags arg_cat_flags = CAT_CONFIG_OFF;
@@ -31,6 +31,14 @@ static PagerFlags arg_pager_flags = 0;
 
 STATIC_DESTRUCTOR_REGISTER(arg_prefixes, strv_freep);
 
+COMMAND(
+        "systemd-sysctl\0",
+        "Apply kernel sysctl settings.",
+        .argspec = "[CONFIGURATION FILE…]\0",
+        .man_pages = "systemd-sysctl.service.8\0",
+        .pager_flags = &arg_pager_flags,
+);
+
 typedef struct SysctlOption {
         char *key;
         char *value;
@@ -317,48 +325,6 @@ static int cat_config(char **files) {
         return cat_files(NULL, files, arg_cat_flags);
 }
 
-static int help(void) {
-        _cleanup_free_ char *link = NULL;
-        _cleanup_(table_unrefp) Table *commands = NULL, *options = NULL;
-        int r;
-
-        r = terminal_urlify_man("systemd-sysctl.service", "8", &link);
-        if (r < 0)
-                return log_oom();
-
-        r = option_parser_get_help_table(&commands);
-        if (r < 0)
-                return r;
-
-        r = option_parser_get_help_table_group("Options", &options);
-        if (r < 0)
-                return r;
-
-        (void) table_sync_column_widths(0, commands, options);
-
-        printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n"
-               "\n%sApplies kernel sysctl settings.%s\n"
-               "\n%sCommands:%s\n",
-               program_invocation_short_name,
-               ansi_highlight(),
-               ansi_normal(),
-               ansi_underline(),
-               ansi_normal());
-
-        r = table_print_or_warn(commands);
-        if (r < 0)
-                return r;
-
-        printf("\n%sOptions:%s\n", ansi_underline(), ansi_normal());
-
-        r = table_print_or_warn(options);
-        if (r < 0)
-                return r;
-
-        printf("\nSee the %s for details.\n", link);
-        return 0;
-}
-
 static int parse_argv(int argc, char *argv[], char ***remaining_args) {
         assert(argc >= 0);
         assert(argv);
@@ -369,8 +335,10 @@ static int parse_argv(int argc, char *argv[], char ***remaining_args) {
         FOREACH_OPTION_OR_RETURN(c, &opts)
                 switch (c) {
 
+                OPTION_GROUP("Commands"): {}
+
                 OPTION_COMMON_HELP:
-                        return help();
+                        return command_print_help("systemd-sysctl");
 
                 OPTION_COMMON_VERSION:
                         return version();
@@ -422,6 +390,9 @@ static int parse_argv(int argc, char *argv[], char ***remaining_args) {
                             "Treat arguments as configuration lines"):
                         arg_inline = true;
                         break;
+
+                OPTION_COMMON_INTROSPECT_CLI:
+                        return introspect_cli(SD_JSON_FORMAT_OFF);
                 }
 
         *remaining_args = option_parser_get_args(&opts);

test/units/TEST-74-AUX-UTILS.introspect-cli.sh

@@ -87,6 +87,7 @@ INTROSPECTABLE=(
     systemd-storage-block
     systemd-storage-fs
     systemd-storagetm
+    systemd-sysctl
     systemd-sysinstall
     systemd-tpm2-clear
     systemd-tpm2-setup