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_SetResultFormatted(interp, "%#s, %s command \"%#s\": should be ", cmd, type, subcmd);
  45     add_commands(interp, command_table, ", ");
  46 }
  47
  48 static void show_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * command_table, int argc,
  49     Jim_Obj *const *argv)
  50 {
  51     Jim_SetResultFormatted(interp, "Usage: \"%#s command ... \", where command is one of: ", argv[0]);
  52     add_commands(interp, command_table, ", ");
  53 }
  54
  55 static void add_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * ct, Jim_Obj *cmd)
  56 {
  57     if (cmd) {
  58         Jim_AppendStrings(interp, Jim_GetResult(interp), Jim_String(cmd), " ", NULL);
  59     }
  60     Jim_AppendStrings(interp, Jim_GetResult(interp), ct->cmd, NULL);
  61     if (ct->args && *ct->args) {
  62         Jim_AppendStrings(interp, Jim_GetResult(interp), " ", ct->args, NULL);
  63     }
  64 }
  65
  66 static void set_wrong_args(Jim_Interp *interp, const jim_subcmd_type * command_table, Jim_Obj *subcmd)
  67 {
  68     Jim_SetResultString(interp, "wrong # args: should be \"", -1);
  69     add_cmd_usage(interp, command_table, subcmd);
  70     Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);
  71 }
  72
  73 /* internal rep is stored in ptrIntvalue
  74  *  ptr = command_table
  75  *  int1 = index
  76  */
  77 static const Jim_ObjType subcmdLookupObjType = {
  78     "subcmd-lookup",
  79     NULL,
  80     NULL,
  81     NULL,
  82     JIM_TYPE_REFERENCES
  83 };
  84
  85 const jim_subcmd_type *Jim_ParseSubCmd(Jim_Interp *interp, const jim_subcmd_type * command_table,
  86     int argc, Jim_Obj *const *argv)
  87 {
  88     const jim_subcmd_type *ct;
  89     const jim_subcmd_type *partial = 0;
  90     int cmdlen;
  91     Jim_Obj *cmd;
  92     const char *cmdstr;
  93     int help = 0;
  94
  95     if (argc < 2) {
  96         Jim_SetResultFormatted(interp, "wrong # args: should be \"%#s command ...\"\n"
  97             "Use \"%#s -help ?command?\" for help", argv[0], argv[0]);
  98         return 0;
  99     }
 100
 101     cmd = argv[1];
 102
 103     /* Use cached lookup if possible */
 104     if (cmd->typePtr == &subcmdLookupObjType) {
 105         if (cmd->internalRep.ptrIntValue.ptr == command_table) {
 106             ct = command_table + cmd->internalRep.ptrIntValue.int1;
 107             goto found;
 108         }
 109     }
 110
 111     /* Check for the help command */
 112     if (Jim_CompareStringImmediate(interp, cmd, "-help")) {
 113         if (argc == 2) {
 114             /* Usage for the command, not the subcommand */
 115             show_cmd_usage(interp, command_table, argc, argv);
 116             return &dummy_subcmd;
 117         }
 118         help = 1;
 119
 120         /* Skip the 'help' command */
 121         cmd = argv[2];
 122     }
 123
 124     /* Check for special builtin '-commands' command first */
 125     if (Jim_CompareStringImmediate(interp, cmd, "-commands")) {
 126         /* Build the result here */
 127         Jim_SetResult(interp, Jim_NewEmptyStringObj(interp));
 128         add_commands(interp, command_table, " ");
 129         return &dummy_subcmd;
 130     }
 131
 132     cmdstr = Jim_GetString(cmd, &cmdlen);
 133
 134     for (ct = command_table; ct->cmd; ct++) {
 135         if (Jim_CompareStringImmediate(interp, cmd, ct->cmd)) {
 136             /* Found an exact match */
 137             break;
 138         }
 139         if (strncmp(cmdstr, ct->cmd, cmdlen) == 0) {
 140             if (partial) {
 141                 /* Ambiguous */
 142                 if (help) {
 143                     /* Just show the top level help here */
 144                     show_cmd_usage(interp, command_table, argc, argv);
 145                     return &dummy_subcmd;
 146                 }
 147                 bad_subcmd(interp, command_table, "ambiguous", argv[0], argv[1 + help]);
 148                 return 0;
 149             }
 150             partial = ct;
 151         }
 152         continue;
 153     }
 154
 155     /* If we had an unambiguous partial match */
 156     if (partial && !ct->cmd) {
 157         ct = partial;
 158     }
 159
 160     if (!ct->cmd) {
 161         /* No matching command */
 162         if (help) {
 163             /* Just show the top level help here */
 164             show_cmd_usage(interp, command_table, argc, argv);
 165             return &dummy_subcmd;
 166         }
 167         bad_subcmd(interp, command_table, "unknown", argv[0], argv[1 + help]);
 168         return 0;
 169     }
 170
 171     if (help) {
 172         Jim_SetResultString(interp, "Usage: ", -1);
 173         /* subcmd */
 174         add_cmd_usage(interp, ct, argv[0]);
 175         return &dummy_subcmd;
 176     }
 177
 178     /* Cache the result for a successful non-help lookup */
 179     Jim_FreeIntRep(interp, cmd);
 180     cmd->typePtr = &subcmdLookupObjType;
 181     cmd->internalRep.ptrIntValue.ptr = (void *)command_table;
 182     cmd->internalRep.ptrIntValue.int1 = ct - command_table;
 183
 184 found:
 185     /* Check the number of args */
 186     if (argc - 2 < ct->minargs || (ct->maxargs >= 0 && argc - 2 > ct->maxargs)) {
 187         Jim_SetResultString(interp, "wrong # args: should be \"", -1);
 188         /* subcmd */
 189         add_cmd_usage(interp, ct, argv[0]);
 190         Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);
 191
 192         return 0;
 193     }
 194
 195     /* Good command */
 196     return ct;
 197 }
 198
 199 int Jim_CallSubCmd(Jim_Interp *interp, const jim_subcmd_type * ct, int argc, Jim_Obj *const *argv)
 200 {
 201     int ret = JIM_ERR;
 202
 203     if (ct) {
 204         if (ct->flags & JIM_MODFLAG_FULLARGV) {
 205             ret = ct->function(interp, argc, argv);
 206         }
 207         else {
 208             ret = ct->function(interp, argc - 2, argv + 2);
 209         }
 210         if (ret < 0) {
 211             set_wrong_args(interp, ct, argv[0]);
 212             ret = JIM_ERR;
 213         }
 214     }
 215     return ret;
 216 }
 217
 218 int Jim_SubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 219 {
 220     const jim_subcmd_type *ct =
 221         Jim_ParseSubCmd(interp, (const jim_subcmd_type *)Jim_CmdPrivData(interp), argc, argv);
 222
 223     return Jim_CallSubCmd(interp, ct, argc, argv);
 224 }