provide support for usage()

diff --git a/servers/slapd/main.c b/servers/slapd/main.c
index 3fe61d6c07001163ad1b7d1abd71aa916435a283..4c31804531739b55d4b2fc40ad4e35fa2bfde4cc 100644 (file)
--- a/servers/slapd/main.c
+++ b/servers/slapd/main.c
@@ -160,12 +160,26 @@ slapd_opt_slp( const char *val, void *arg )
 #endif
 }
 
+/*
+ * Option helper structure:
+ * 
+ * oh_nam      is left-hand part of <option>[=<value>]
+ * oh_fnc      is handler function
+ * oh_arg      is an optional arg to oh_fnc
+ * oh_usage    is the one-line usage string related to the option,
+ *             which is assumed to start with <option>[=<value>]
+ *
+ * please leave valid options in the structure, and optionally #ifdef
+ * their processing inside the helper, so that reasonable and helpful
+ * error messages can be generated if a disabled option is requested.
+ */
 struct option_helper {
        struct berval   oh_name;
        int             (*oh_fnc)(const char *val, void *arg);
        void            *oh_arg;
+       const char      *oh_usage;
 } option_helpers[] = {
-       { BER_BVC("slp"),       slapd_opt_slp,  NULL },
+       { BER_BVC("slp"),       slapd_opt_slp,  NULL, "slp[={on|off}] enable/disable SLP" },
        { BER_BVNULL }
 };
 
@@ -190,10 +204,18 @@ usage( char *name )
                "\t-l facility\tSyslog facility (default: LOCAL4)\n"
 #endif
                "\t-n serverName\tService name\n"
-               "\t-o <opt>[=val]\tGeneric means to specify options; supported options:\n"
-#ifdef HAVE_SLP
-               "\t\t\t\tslp[={on|off}]\n"
-#endif
+               "\t-o <opt>[=val] Generic means to specify options" );
+       if ( !BER_BVISNULL( &option_helpers[0].oh_name ) ) {
+               int     i;
+
+               fprintf( stderr, "; supported options:\n" );
+               for ( i = 0; !BER_BVISNULL( &option_helpers[i].oh_name ); i++) {
+                       fprintf( stderr, "\t\t%s\n", option_helpers[i].oh_usage );
+               }
+       } else {
+               fprintf( stderr, "\n" );
+       }
+       fprintf( stderr,        
 #ifdef HAVE_CHROOT
                "\t-r directory\tSandbox directory to chroot to\n"
 #endif