udev/iocost: convert to VERB_COMMAND and add --introspect-cli

The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. The tool has no man page of its own, so
iocost.conf(5), which describes it, is referenced. The test now also looks
for commands in /usr/lib/udev, where the udev helpers are installed.

src/udev/iocost/iocost.c

@@ -3,6 +3,7 @@
 #include <stdio.h>
 
 #include "sd-device.h"
+#include "sd-json.h"
 
 #include "alloc-util.h"
 #include "build.h"
@@ -10,10 +11,7 @@
 #include "conf-parser.h"
 #include "device-util.h"
 #include "devnum-util.h"
-#include "format-table.h"
-#include "help-util.h"
 #include "main-func.h"
-#include "options.h"
 #include "string-util.h"
 #include "strv.h"
 #include "udev-util.h"
@@ -22,6 +20,12 @@
 static char *arg_target_solution = NULL;
 STATIC_DESTRUCTOR_REGISTER(arg_target_solution, freep);
 
+COMMAND(
+        "iocost\0",
+        "Set up iocost model and qos solutions for block devices.",
+        .man_pages = "iocost.conf.5\0",
+);
+
 static int parse_config(void) {
         static const ConfigTableItem items[] = {
                 { "IOCost", "TargetSolution", config_parse_string, 0, &arg_target_solution },
@@ -51,33 +55,7 @@ static int parse_config(void) {
         return 0;
 }
 
-static int help(void) {
-        _cleanup_(table_unrefp) Table *options = NULL, *verbs = NULL;
-        int r;
-
-        r = option_parser_get_help_table(&options);
-        if (r < 0)
-                return r;
-
-        r = verbs_get_help_table(&verbs);
-        if (r < 0)
-                return r;
-
-        (void) table_sync_column_widths(0, options, verbs);
-
-        help_cmdline("[OPTIONS...] COMMAND");
-        help_abstract("Set up iocost model and qos solutions for block devices.");
-
-        help_section("Commands");
-        r = table_print_or_warn(verbs);
-        if (r < 0)
-                return r;
-
-        help_section("Options");
-        return table_print_or_warn(options);
-}
-
-VERB_COMMON_HELP_HIDDEN(help);
+VERB_COMMON_HELP_AUTO_HIDDEN("iocost");
 
 static int parse_argv(int argc, char *argv[], char ***remaining_args) {
         assert(argc >= 0);
@@ -90,10 +68,13 @@ static int parse_argv(int argc, char *argv[], char ***remaining_args) {
                 switch (c) {
 
                 OPTION_COMMON_HELP:
-                        return help();
+                        return command_print_help("iocost");
 
                 OPTION_COMMON_VERSION:
                         return version();
+
+                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

@@ -3,9 +3,9 @@
 set -eux
 set -o pipefail
 
-# Some commands are in $PATH, others are in our private directory.
-# Check the other location too.
-PATH=$PATH:/usr/lib/systemd
+# Some commands are in $PATH, others are in our private directories.
+# Check the other locations too.
+PATH=$PATH:/usr/lib/systemd:/usr/lib/udev
 
 export SYSTEMD_PAGER=cat
 
@@ -17,6 +17,7 @@ INTROSPECTABLE=(
     homectl
     hostnamectl
     importctl
+    iocost
     journalctl
     localectl
     loginctl