jim-subcmd.c

   1 /*
   2  * Makes it easy to support "ensembles". i.e. commands with subcommands
   3  * like [string] and [array]
   4  *
   5  * (c) 2008 Steve Bennett <steveb@workware.net.au>
   6  *
   7  */
   8 #include <stdio.h>
   9 #include <string.h>
  10
  11 #include <jim-subcmd.h>
  12
  13 /**
  14  * Implements the common 'commands' subcommand
  15  */
  16 static int subcmd_null(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
  17 {
  18     /* Nothing to do, since the result has already been created */
  19     return JIM_OK;
  20 }
  21
  22 /**
  23  * Do-nothing command to support -commands and -usage
  24  */
  25 static const jim_subcmd_type dummy_subcmd = {
  26     "dummy", NULL, subcmd_null, 0, 0, JIM_MODFLAG_HIDDEN
  27 };
  28
  29 static void add_commands(Jim_Interp *interp, const jim_subcmd_type * ct, const char *sep)
  30 {
  31     const char *s = "";
  32
  33     for (; ct->cmd; ct++) {
  34         if (!(ct->flags & JIM_MODFLAG_HIDDEN)) {
  35             Jim_AppendStrings(interp, Jim_GetResult(interp), s, ct->cmd, NULL);
  36             s = sep;
  37         }
  38     }
  39 }
  40
  41 static void bad_subcmd(Jim_Interp *interp, const jim_subcmd_type * command_table, const char *type,
  42     Jim_Obj *cmd, Jim_Obj *subcmd)
  43 {
  44     Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
  45     Jim_AppendStrings(interp, Jim_GetResult(interp), Jim_String(cmd), ", ", type,
  46         " command \"", Jim_String(subcmd), "\": should be ", NULL);
  47     add_commands(interp, command_table, ", ");
  48 }
  49
  50 static void show_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * command_table, int argc,
  51     Jim_Obj *const *argv)
  52 {
  53     Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
  54     Jim_AppendStrings(interp, Jim_GetResult(interp), "Usage: \"", Jim_String(argv[0]),
  55         " command ... \", where command is one of: ", NULL);
  56     add_commands(interp, command_table, ", ");
  57 }
  58
  59 static void add_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * ct, Jim_Obj *cmd)
  60 {
  61     if (cmd) {
  62         Jim_AppendStrings(interp, Jim_GetResult(interp), Jim_String(cmd), " ", NULL);
  63     }
  64     Jim_AppendStrings(interp, Jim_GetResult(interp), ct->cmd, NULL);
  65     if (ct->args && *ct->args) {
  66         Jim_AppendStrings(interp, Jim_GetResult(interp), " ", ct->args, NULL);
  67     }
  68 }
  69
  70 static void set_wrong_args(Jim_Interp *interp, const jim_subcmd_type * command_table, Jim_Obj *subcmd)
  71 {
  72     Jim_SetResultString(interp, "wrong # args: should be \"", -1);
  73     add_cmd_usage(interp, command_table, subcmd);
  74     Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);
  75 }
  76
  77 const jim_subcmd_type *Jim_ParseSubCmd(Jim_Interp *interp, const jim_subcmd_type * command_table,
  78     int argc, Jim_Obj *const *argv)
  79 {
  80     const jim_subcmd_type *ct;
  81     const jim_subcmd_type *partial = 0;
  82     int cmdlen;
  83     Jim_Obj *cmd;
  84     const char *cmdstr;
  85     const char *cmdname;
  86     int help = 0;
  87
  88     cmdname = Jim_String(argv[0]);
  89
  90     if (argc < 2) {
  91         Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
  92         Jim_AppendStrings(interp, Jim_GetResult(interp), "wrong # args: should be \"", cmdname,
  93             " command ...\"\n", NULL);
  94         Jim_AppendStrings(interp, Jim_GetResult(interp), "Use \"", cmdname, " -help ?command?\" for help", NULL);
  95         return 0;
  96     }
  97
  98     cmd = argv[1];
  99
 100     /* Check for the help command */
 101     if (Jim_CompareStringImmediate(interp, cmd, "-help")) {
 102         if (argc == 2) {
 103             /* Usage for the command, not the subcommand */
 104             show_cmd_usage(interp, command_table, argc, argv);
 105             return &dummy_subcmd;
 106         }
 107         help = 1;
 108
 109         /* Skip the 'help' command */
 110         cmd = argv[2];
 111     }
 112
 113     /* Check for special builtin '-commands' command first */
 114     if (Jim_CompareStringImmediate(interp, cmd, "-commands")) {
 115         /* Build the result here */
 116         Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
 117         add_commands(interp, command_table, " ");
 118         return &dummy_subcmd;
 119     }
 120
 121     cmdstr = Jim_GetString(cmd, &cmdlen);
 122
 123     for (ct = command_table; ct->cmd; ct++) {
 124         if (Jim_CompareStringImmediate(interp, cmd, ct->cmd)) {
 125             /* Found an exact match */
 126             break;
 127         }
 128         if (strncmp(cmdstr, ct->cmd, cmdlen) == 0) {
 129             if (partial) {
 130                 /* Ambiguous */
 131                 if (help) {
 132                     /* Just show the top level help here */
 133                     show_cmd_usage(interp, command_table, argc, argv);
 134                     return &dummy_subcmd;
 135                 }
 136                 bad_subcmd(interp, command_table, "ambiguous", argv[0], argv[1 + help]);
 137                 return 0;
 138             }
 139             partial = ct;
 140         }
 141         continue;
 142     }
 143
 144     /* If we had an unambiguous partial match */
 145     if (partial && !ct->cmd) {
 146         ct = partial;
 147     }
 148
 149     if (!ct->cmd) {
 150         /* No matching command */
 151         if (help) {
 152             /* Just show the top level help here */
 153             show_cmd_usage(interp, command_table, argc, argv);
 154             return &dummy_subcmd;
 155         }
 156         bad_subcmd(interp, command_table, "unknown", argv[0], argv[1 + help]);
 157         return 0;
 158     }
 159
 160     if (help) {
 161         Jim_SetResultString(interp, "Usage: ", -1);
 162         /* subcmd */
 163         add_cmd_usage(interp, ct, argv[0]);
 164         return &dummy_subcmd;
 165     }
 166
 167     /* Check the number of args */
 168     if (argc - 2 < ct->minargs || (ct->maxargs >= 0 && argc - 2 > ct->maxargs)) {
 169         Jim_SetResultString(interp, "wrong # args: should be \"", -1);
 170         /* subcmd */
 171         add_cmd_usage(interp, ct, argv[0]);
 172         Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);
 173
 174         return 0;
 175     }
 176
 177     /* Good command */
 178     return ct;
 179 }
 180
 181 int Jim_CallSubCmd(Jim_Interp *interp, const jim_subcmd_type * ct, int argc, Jim_Obj *const *argv)
 182 {
 183     int ret = JIM_ERR;
 184
 185     if (ct) {
 186         if (ct->flags & JIM_MODFLAG_FULLARGV) {
 187             ret = ct->function(interp, argc, argv);
 188         }
 189         else {
 190             ret = ct->function(interp, argc - 2, argv + 2);
 191         }
 192         if (ret < 0) {
 193             set_wrong_args(interp, ct, argv[0]);
 194             ret = JIM_ERR;
 195         }
 196     }
 197     return ret;
 198 }
 199
 200 int Jim_SubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 201 {
 202     const jim_subcmd_type *ct =
 203         Jim_ParseSubCmd(interp, (const jim_subcmd_type *)Jim_CmdPrivData(interp), argc, argv);
 204
 205     return Jim_CallSubCmd(interp, ct, argc, argv);
 206 }