hal/tools/hal_find_by_capability.c

/***************************************************************************
 * CVSID: $Id$
 *
 * hal_find_by_capability.c : Find hal devices
 *
 * Copyright (C) 2005 David Zeuthen, <david@fubar.dk>
 *
 * Licensed under the Academic Free License version 2.1
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 **************************************************************************/


#ifdef HAVE_CONFIG_H
#  include <config.h>
#endif

#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <getopt.h>

#include <libhal.h>


/** Print out program usage.
 *
 *  @param  argc                Number of arguments given to program
 *  @param  argv                Arguments given to program
 */
static void
usage (int argc, char *argv[])
{
    fprintf (stderr,
 "\n"
 "usage : hal-find-by-capability --capability <capability>\n"
 "                              [--help] [--verbose] [--version]\n");
    fprintf (stderr,
 "\n"
 "        --capability     HAL Device Capability to search for\n"
 "        --verbose        Be verbose\n"
 "        --version        Show version and exit\n"
 "        --help           Show this information and exit\n"
 "\n"
 "This program prints the Unique Device Identifiers for HAL device\n"
 "objects of a given capability on stdout and exits with exit code 0\n"
 "If there is an error, the program exits with an exit code different\n"
 "from 0.\n"
 "\n");
}

/** Entry point
 *
 *  @param  argc                Number of arguments given to program
 *  @param  argv                Arguments given to program
 *  @return                     Return code
 */
int
main (int argc, char *argv[])
{
    int i;
    int num_udis;
    char **udis;
    char *capability = NULL;
    dbus_bool_t is_verbose = FALSE;
    dbus_bool_t is_version = FALSE;
    DBusError error;
    LibHalContext *hal_ctx;

    if (argc <= 1) {
        usage (argc, argv);
        return 1;
    }

    while (1) {
        int c;
        int option_index = 0;
        const char *opt;
        static struct option long_options[] = {
            {"capability", 1, NULL, 0},
            {"verbose", 0, NULL, 0},
            {"version", 0, NULL, 0},
            {"help", 0, NULL, 0},
            {NULL, 0, NULL, 0}
        };

        c = getopt_long (argc, argv, "",
                 long_options, &option_index);
        if (c == -1)
            break;

        switch (c) {
        case 0:
            opt = long_options[option_index].name;

            if (strcmp (opt, "help") == 0) {
                usage (argc, argv);
                return 0;
            } else if (strcmp (opt, "verbose") == 0) {
                is_verbose = TRUE;
            } else if (strcmp (opt, "version") == 0) {
                is_version = TRUE;
            } else if (strcmp (opt, "capability") == 0) {
                capability = strdup (optarg);
            }
            break;

        default:
            usage (argc, argv);
            return 1;
            break;
        }
    }

    if (is_version) {
        printf ("hal-find-by-capability " PACKAGE_VERSION "\n");
        return 0;
    }

    if (capability == NULL) {
        usage (argc, argv);
        return 1;
    }

    dbus_error_init (&error);
    if ((hal_ctx = libhal_ctx_new ()) == NULL) {
        fprintf (stderr, "error: libhal_ctx_new\n");
        LIBHAL_FREE_DBUS_ERROR (&error);
        return 1;
    }
    if (!libhal_ctx_set_dbus_connection (hal_ctx, dbus_bus_get (DBUS_BUS_SYSTEM, &error))) {
        fprintf (stderr, "error: libhal_ctx_set_dbus_connection: %s: %s\n", error.name, error.message);
        LIBHAL_FREE_DBUS_ERROR (&error);
        return 1;
    }
    if (!libhal_ctx_init (hal_ctx, &error)) {
        if (dbus_error_is_set(&error)) {
            fprintf (stderr, "error: libhal_ctx_init: %s: %s\n", error.name, error.message);
            LIBHAL_FREE_DBUS_ERROR (&error);
        }
        fprintf (stderr, "Could not initialise connection to hald.\n"
                 "Normally this means the HAL daemon (hald) is not running or not ready.\n");
        return 1;
    }


    udis = libhal_find_device_by_capability (hal_ctx, capability, &num_udis, &error);

    if (dbus_error_is_set (&error)) {
        fprintf (stderr, "error: %s: %s\n", error.name, error.message);
        LIBHAL_FREE_DBUS_ERROR (&error);
        return 1;
    }

    if (is_verbose)
        printf ("Found %d device objects of capability '%s'\n", num_udis, capability);

    if (num_udis == 0) {
        return 1;
    }

    for (i = 0; i < num_udis; i++) {
        printf ("%s\n", udis[i]);
    }

    libhal_free_string_array (udis);

    return 0;
}

/**
 * @}
 */