Implement help subommand.

diff --git a/dss.c b/dss.c
index 0992ec6fd18651f85c2bab2c7d8d45603b3a786c..8e369ca70bb2456451c9a4a813605f160e37deb4 100644 (file)
--- a/dss.c
+++ b/dss.c
@@ -1837,20 +1837,57 @@ static void handle_version_and_help(void)
        exit(EXIT_SUCCESS);
 }
 
-static void show_subcommand_summary(void)
+static void show_subcommand_summary(bool verbose)
 {
        const struct lls_command *cmd;
        int i;
 
-       printf("Available subcommands:\n");
+       printf("Available subcommands: ");
+       if (!verbose) {
+               for (i = 1; (cmd = lls_cmd(i, dss_suite)); i++) {
+                       if (i > 1)
+                               printf(", ");
+                       printf("%s", lls_command_name(cmd));
+               }
+               return;
+       }
+       printf("\n");
        for (i = 1; (cmd = lls_cmd(i, dss_suite)); i++) {
                const char *name = lls_command_name(cmd);
                const char *purpose = lls_purpose(cmd);
                printf("%-11s%s\n", name, purpose);
        }
-       exit(EXIT_SUCCESS);
 }
 
+static int com_help(void)
+{
+       int ret;
+       char *errctx, *help;
+       const char *arg;
+       const struct lls_command *cmd;
+
+       ret = lls_check_arg_count(sublpr, 0, 1, &errctx);
+       if (ret < 0)
+               return lopsub_error(ret, &errctx);
+       if (lls_num_inputs(sublpr) == 0) {
+               show_subcommand_summary(OPT_GIVEN(HELP, LONG));
+               return 0;
+       }
+       arg = lls_input(0, sublpr);
+       ret = lls_lookup_subcmd(arg, dss_suite, &errctx);
+       if (ret < 0)
+               return lopsub_error(ret, &errctx);
+       cmd = lls_cmd(ret, dss_suite);
+       if (OPT_GIVEN(HELP, LONG))
+               help = lls_long_help(cmd);
+       else
+               help = lls_short_help(cmd);
+       printf("%s\n", help);
+       free(help);
+       return 0;
+}
+EXPORT_CMD_HANDLER(help);
+
 int main(int argc, char **argv)
 {
        int ret;
@@ -1869,8 +1906,11 @@ int main(int argc, char **argv)
                goto out;
        handle_version_and_help();
        num_inputs = lls_num_inputs(lpr);
-       if (num_inputs == 0)
-               show_subcommand_summary();
+       if (num_inputs == 0) { /* show verbose summary */
+               show_subcommand_summary(true);
+               ret = 0;
+               goto out;
+       }
        ret = lls_lookup_subcmd(argv[argc - num_inputs], dss_suite, &errctx);
        if (ret < 0) {
                ret = lopsub_error(ret, &errctx);

diff --git a/dss.suite b/dss.suite
index f9cf8af5993345452fddc7b3d9790d0d7e6d7a13..6d1ed4ab0dd4f5a47eb10c720f5fff5869ac5914 100644 (file)
--- a/dss.suite
+++ b/dss.suite
@@ -540,6 +540,27 @@ caption = Subcommands
                exits successfully or prints information about the first syntax error
                detected and terminates with exit code 1.
        [/description]
+[subcommand help]
+       purpose = list available subcommands or print subcommand-specific help
+       non-opts-name = [subcommand]
+       [description]
+               Without any arguments, help prints the list of available
+               subcommands. When called with a subcommand name argument, it prints
+               the help text of the given subcommand.
+       [/description]
+       [option long]
+               short_opt = l
+               summary = show the long help text
+               [help]
+                       If the optional argument is supplied, the long help text contains the
+                       synopsis, the purpose and the description of the specified subcommand,
+                       followed by the option list including summary and help text of each
+                       option. Without --long, the short help is shown instead. This omits
+                       the description of the subcommand and the option help.
+
+                       If no subcommand is supplied but --long is given, the list contains the
+                       purpose of each subcommand.
+               [/help]
 
 [section copyright]
        Written by Andre Noll