jim-subcmd.c

/*
 * Makes it easy to support "ensembles". i.e. commands with subcommands
 * like [string] and [array]
 *
 * (c) 2008 Steve Bennett <steveb@workware.net.au>
 *
 */
#include <stdio.h>
#include <string.h>

#include <jim-subcmd.h>

/**
 * Implements the common 'commands' subcommand
 */
static int subcmd_null(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
    /* Nothing to do, since the result has already been created */
    return JIM_OK;
}

/**
 * Do-nothing command to support -commands and -usage
 */
static const jim_subcmd_type dummy_subcmd = {
    "dummy", NULL, subcmd_null, 0, 0, JIM_MODFLAG_HIDDEN
};

/* Creates and returns a string (object) of each non-hidden command in 'ct',
 * sorted and separated with the given separator string.
 *
 * For example, if there are two commands, "def" and "abc", with a separator of "; ",
 * the returned string will be "abc; def"
 *
 * The returned object has a reference count of 0.
 */
static Jim_Obj *subcmd_cmd_list(Jim_Interp *interp, const jim_subcmd_type * ct, const char *sep)
{
    /* Create a list to sort before joining */
    Jim_Obj *listObj = Jim_NewListObj(interp, NULL, 0);
    Jim_Obj *sortCmd[2];

    for (; ct->cmd; ct++) {
        if (!(ct->flags & JIM_MODFLAG_HIDDEN)) {
            Jim_ListAppendElement(interp, listObj, Jim_NewStringObj(interp, ct->cmd, -1));
        }
    }

    /* There is no direct API to sort a list, so just invoke lsort here. */
    sortCmd[0] = Jim_NewStringObj(interp, "lsort", -1);
    sortCmd[1] = listObj;
    /* Leaves the result in the interpreter result */
    if (Jim_EvalObjVector(interp, 2, sortCmd) == JIM_OK) {
        return Jim_ListJoin(interp, Jim_GetResult(interp), sep, strlen(sep));
    }
    /* lsort can't really fail (normally), but if it does, just return the error as the result */
    return Jim_GetResult(interp);
}

static void bad_subcmd(Jim_Interp *interp, const jim_subcmd_type * command_table, const char *type,
    Jim_Obj *cmd, Jim_Obj *subcmd)
{
    Jim_SetResultFormatted(interp, "%#s, %s command \"%#s\": should be %#s", cmd, type,
        subcmd, subcmd_cmd_list(interp, command_table, ", "));
}

static void show_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * command_table, int argc,
    Jim_Obj *const *argv)
{
    Jim_SetResultFormatted(interp, "Usage: \"%#s command ... \", where command is one of: %#s",
        argv[0], subcmd_cmd_list(interp, command_table, ", "));
}

static void add_cmd_usage(Jim_Interp *interp, const jim_subcmd_type * ct, Jim_Obj *cmd)
{
    if (cmd) {
        Jim_AppendStrings(interp, Jim_GetResult(interp), Jim_String(cmd), " ", NULL);
    }
    Jim_AppendStrings(interp, Jim_GetResult(interp), ct->cmd, NULL);
    if (ct->args && *ct->args) {
        Jim_AppendStrings(interp, Jim_GetResult(interp), " ", ct->args, NULL);
    }
}

void Jim_SubCmdArgError(Jim_Interp *interp, const jim_subcmd_type * ct, Jim_Obj *subcmd)
{
    Jim_SetResultString(interp, "wrong # args: should be \"", -1);
    add_cmd_usage(interp, ct, subcmd);
    Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);
}

/* internal rep is stored in ptrIntvalue
 *  ptr = command_table
 *  int1 = index
 */
static const Jim_ObjType subcmdLookupObjType = {
    "subcmd-lookup",
    NULL,
    NULL,
    NULL,
    JIM_TYPE_REFERENCES
};

const jim_subcmd_type *Jim_ParseSubCmd(Jim_Interp *interp, const jim_subcmd_type * command_table,
    int argc, Jim_Obj *const *argv)
{
    const jim_subcmd_type *ct;
    const jim_subcmd_type *partial = 0;
    int cmdlen;
    Jim_Obj *cmd;
    const char *cmdstr;
    int help = 0;
    int argsok = 1;

    if (argc < 2) {
        Jim_SetResultFormatted(interp, "wrong # args: should be \"%#s command ...\"\n"
            "Use \"%#s -help ?command?\" for help", argv[0], argv[0]);
        return 0;
    }

    cmd = argv[1];

    /* Use cached lookup if possible */
    if (cmd->typePtr == &subcmdLookupObjType) {
        if (cmd->internalRep.ptrIntValue.ptr == command_table) {
            ct = command_table + cmd->internalRep.ptrIntValue.int1;
            goto found;
        }
    }

    /* Check for the help command */
    if (Jim_CompareStringImmediate(interp, cmd, "-help")) {
        if (argc == 2) {
            /* Usage for the command, not the subcommand */
            show_cmd_usage(interp, command_table, argc, argv);
            return &dummy_subcmd;
        }
        help = 1;

        /* Skip the 'help' command */
        cmd = argv[2];
    }

    /* Check for special builtin '-commands' command first */
    if (Jim_CompareStringImmediate(interp, cmd, "-commands")) {
        Jim_SetResult(interp, subcmd_cmd_list(interp, command_table, " "));
        return &dummy_subcmd;
    }

    cmdstr = Jim_GetString(cmd, &cmdlen);

    for (ct = command_table; ct->cmd; ct++) {
        if (Jim_CompareStringImmediate(interp, cmd, ct->cmd)) {
            /* Found an exact match */
            break;
        }
        if (strncmp(cmdstr, ct->cmd, cmdlen) == 0) {
            if (partial) {
                /* Ambiguous */
                if (help) {
                    /* Just show the top level help here */
                    show_cmd_usage(interp, command_table, argc, argv);
                    return &dummy_subcmd;
                }
                bad_subcmd(interp, command_table, "ambiguous", argv[0], argv[1 + help]);
                return 0;
            }
            partial = ct;
        }
        continue;
    }

    /* If we had an unambiguous partial match */
    if (partial && !ct->cmd) {
        ct = partial;
    }

    if (!ct->cmd) {
        /* No matching command */
        if (help) {
            /* Just show the top level help here */
            show_cmd_usage(interp, command_table, argc, argv);
            return &dummy_subcmd;
        }
        bad_subcmd(interp, command_table, "unknown", argv[0], argv[1 + help]);
        return 0;
    }

    if (help) {
        Jim_SetResultString(interp, "Usage: ", -1);
        /* subcmd */
        add_cmd_usage(interp, ct, argv[0]);
        return &dummy_subcmd;
    }

    /* Cache the result for a successful non-help lookup */
    Jim_FreeIntRep(interp, cmd);
    cmd->typePtr = &subcmdLookupObjType;
    cmd->internalRep.ptrIntValue.ptr = (void *)command_table;
    cmd->internalRep.ptrIntValue.int1 = ct - command_table;

found:
    /* Check the number of args */

    if (argc - 2 < ct->minargs) {
        argsok = 0;
    }
    else if (ct->maxargs >= 0 && argc - 2 > ct->maxargs) {
        argsok = 0;
    }
    else if (ct->maxargs < -1 && (argc - 2) % -ct->maxargs != 0) {
        /* -2 means must have n * 2 args */
        argsok = 0;
    }
    if (!argsok) {
        Jim_SetResultString(interp, "wrong # args: should be \"", -1);
        /* subcmd */
        add_cmd_usage(interp, ct, argv[0]);
        Jim_AppendStrings(interp, Jim_GetResult(interp), "\"", NULL);

        return 0;
    }

    /* Good command */
    return ct;
}

int Jim_CallSubCmd(Jim_Interp *interp, const jim_subcmd_type * ct, int argc, Jim_Obj *const *argv)
{
    int ret = JIM_ERR;

    if (ct) {
        if (ct->flags & JIM_MODFLAG_FULLARGV) {
            ret = ct->function(interp, argc, argv);
        }
        else {
            ret = ct->function(interp, argc - 2, argv + 2);
        }
        if (ret < 0) {
            Jim_SubCmdArgError(interp, ct, argv[0]);
            ret = JIM_ERR;
        }
    }
    return ret;
}

int Jim_SubCmdProc(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
{
    const jim_subcmd_type *ct =
        Jim_ParseSubCmd(interp, (const jim_subcmd_type *)Jim_CmdPrivData(interp), argc, argv);

    return Jim_CallSubCmd(interp, ct, argc, argv);
}