HelenOS sources

root/uspace/app/bdsh/cmds/modules/alias/alias.c

DEFINITIONS

1. list_aliases
2. print_alias
3. set_alias
4. validate_name
5. help_cmd_alias
6. cmd_alias

/*
 * Copyright (c) 2018 Matthieu Riolo
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdio.h>
#include <stdlib.h>
#include <str.h>
#include "config.h"
#include "util.h"
#include "errors.h"
#include "entry.h"
#include "alias.h"
#include "cmds.h"

#include <adt/odict.h>

static const char *cmdname = "alias";
static const char *alias_format = "%s='%s'\n";

static void list_aliases()
{
        odlink_t *alias_link = odict_first(&alias_dict);
        while (alias_link != NULL) {
                alias_t *data = odict_get_instance(alias_link, alias_t, odict);
                printf(alias_format, data->name, data->value);
                alias_link = odict_next(alias_link, &alias_dict);
        }
}

static bool print_alias(const char *name)
{
        odlink_t *alias_link = odict_find_eq(&alias_dict, (void *)name, NULL);
        if (alias_link != NULL) {
                alias_t *data = odict_get_instance(alias_link, alias_t, odict);
                printf(alias_format, data->name, data->value);
                return true;
        }

        cli_error(CL_ENOENT, "%s: No alias with the name '%s' exists\n", cmdname, name);
        return false;
}

static errno_t set_alias(const char *name, const char *value)
{
        odlink_t *alias_link = odict_find_eq(&alias_dict, (void *)name, NULL);

        if (alias_link != NULL) {
                /* update existing value */
                alias_t *data = odict_get_instance(alias_link, alias_t, odict);
                char *dup_value = str_dup(value);

                if (dup_value == NULL) {
                        cli_error(CL_ENOMEM, "%s: failing to allocate memory for value\n", cmdname);
                        return ENOMEM;
                }

                free(data->value);
                data->value = dup_value;
        } else {
                /* add new value */
                alias_t *data = (alias_t *)calloc(1, sizeof(alias_t));
                if (data == NULL) {
                        cli_error(CL_ENOMEM, "%s: failing to allocate memory for data container\n", cmdname);
                        return ENOMEM;
                }

                data->name = str_dup(name);
                if (data->name == NULL) {
                        cli_error(CL_ENOMEM, "%s: failing to allocate memory for name\n", cmdname);
                        free(data);
                        return ENOMEM;
                }

                data->value = str_dup(value);
                if (data->value == NULL) {
                        cli_error(CL_ENOMEM, "%s: failing to allocate memory for value\n", cmdname);
                        free(data->name);
                        free(data);
                        return ENOMEM;
                }
                odict_insert(&data->odict, &alias_dict, NULL);
        }

        return EOK;
}

static bool validate_name(const char *name)
{
        while (*name != '\0') {
                if (*name == '/')
                        return false;
                if (*name == ' ')
                        return false;
                if (*name == '\"')
                        return false;
                if (*name == '\'')
                        return false;
                if (*name == '|')
                        return false;

                name++;
        }

        return true;
}

/* Dispays help for alias in various levels */
void help_cmd_alias(unsigned int level)
{
        if (level == HELP_SHORT) {
                printf("`%s' sets an alias, displays an alias or lists all aliases\n", cmdname);
        } else {
                help_cmd_alias(HELP_SHORT);
                printf("Usage: `%s' [newalias[='existingCMD --flags] ...]'\n\n"
                    "If no parameters are given it will display all existing aliases.\n"
                    "If a parameter without an assignment is given, the value of the given alias will be returned.\n"
                    "If a parameter with an assignment is given, the alias will be created or updated for the given value. "
                    "It is possible to create an alias to a different alias. A circularity will prevent an alias to be resolved.\n",
                    cmdname);
        }
}

/* Main entry point for alias, accepts an array of arguments */
int cmd_alias(char **argv)
{

        if (argv[1] == NULL) {
                list_aliases();
                return CMD_SUCCESS;
        }

        size_t i;
        for (i = 1; argv[i] != NULL; i++) {
                char *name = argv[i];
                char *value;
                if ((value = str_chr(name, '=')) != NULL) {
                        name[value - name] = '\0';

                        if (!validate_name(name)) {
                                cli_error(CL_EFAIL, "%s: invalid alias name given\n", cmdname);
                                return CMD_FAILURE;
                        }

                        if (set_alias(name, value + 1) != EOK) {
                                return CMD_FAILURE;
                        }
                } else {
                        if (!print_alias(name)) {
                                return CMD_FAILURE;
                        }
                }
        }

        return CMD_SUCCESS;
}