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

The custom help() is replaced by a COMMAND() description, and
--introspect-cli is added. --help now goes through the pager, like other
commands with --no-pager.

src/delta/delta.c

@@ -2,30 +2,31 @@
 
 #include <unistd.h>
 
+#include "sd-json.h"
+
 #include "alloc-util.h"
+#include "ansi-color.h"
 #include "build.h"
 #include "chase.h"
 #include "dirent-util.h"
 #include "errno-util.h"
 #include "extract-word.h"
 #include "fd-util.h"
-#include "format-table.h"
 #include "fs-util.h"
 #include "glyph-util.h"
 #include "hashmap.h"
 #include "log.h"
 #include "main-func.h"
 #include "nulstr-util.h"
-#include "options.h"
 #include "pager.h"
 #include "parse-argument.h"
 #include "path-util.h"
 #include "pidref.h"
-#include "pretty-print.h"
 #include "process-util.h"
 #include "stat-util.h"
 #include "string-util.h"
 #include "strv.h"
+#include "verbs.h"
 
 static const char prefixes[] =
         "/etc\0"
@@ -67,6 +68,14 @@ static enum {
         (SHOW_MASKED | SHOW_EQUIVALENT | SHOW_REDIRECTED | SHOW_OVERRIDDEN | SHOW_EXTENDED)
 } arg_flags = 0;
 
+COMMAND(
+        "systemd-delta\0",
+        "Find overridden configuration files.",
+        .argspec = "[SUFFIX…]\0",
+        .man_pages = "systemd-delta.1\0",
+        .pager_flags = &arg_pager_flags,
+);
+
 static int equivalent(const char *a, const char *b) {
         _cleanup_free_ char *x = NULL, *y = NULL;
         int r;
@@ -458,31 +467,6 @@ static int process_suffix_chop(const char *arg) {
                                "Invalid suffix specification %s.", arg);
 }
 
-static int help(void) {
-        _cleanup_free_ char *link = NULL;
-        _cleanup_(table_unrefp) Table *options = NULL;
-        int r;
-
-        r = terminal_urlify_man("systemd-delta", "1", &link);
-        if (r < 0)
-                return log_oom();
-
-        r = option_parser_get_help_table(&options);
-        if (r < 0)
-                return r;
-
-        printf("%s [OPTIONS...] [SUFFIX...]\n\n"
-               "Find overridden configuration files.\n\n",
-               program_invocation_short_name);
-
-        r = table_print_or_warn(options);
-        if (r < 0)
-                return r;
-
-        printf("\nSee the %s for details.\n", link);
-        return 0;
-}
-
 static int parse_flags(const char *flag_str, int flags) {
         for (;;) {
                 _cleanup_free_ char *word = NULL;
@@ -524,7 +508,7 @@ static int parse_argv(int argc, char *argv[], char ***ret_args) {
                 switch (c) {
 
                 OPTION_COMMON_HELP:
-                        return help();
+                        return command_print_help("systemd-delta");
 
                 OPTION_COMMON_VERSION:
                         return version();
@@ -548,6 +532,9 @@ static int parse_argv(int argc, char *argv[], char ***ret_args) {
                                 return r;
                         arg_diff = r;
                         break;
+
+                OPTION_COMMON_INTROSPECT_CLI:
+                        return introspect_cli(SD_JSON_FORMAT_OFF);
                 }
 
         *ret_args = option_parser_get_args(&opts);

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

@@ -21,6 +21,7 @@ INTROSPECTABLE=(
     systemd-cat
     systemd-cgls
     systemd-cgtop
+    systemd-delta
     systemd-dissect
     systemd-firstboot
     systemd-hwdb