glib学习笔记之六——处理命令行参数

官方文档：http://developer.gnome.org/glib/stable/glib-Commandline-option-parser.html

在connman中使用GOptionEntry结构体处理命令行参数，结构体形式如下：

static GOptionEntry options[] = {
        { "debug", 'd', G_OPTION_FLAG_OPTIONAL_ARG,
                                G_OPTION_ARG_CALLBACK, parse_debug,
                                "Specify debug options to enable", "DEBUG" },
        { "device", 'i', 0, G_OPTION_ARG_STRING, &option_device,
                        "Specify networking device or interface", "DEV" },
        { "nodevice", 'I', 0, G_OPTION_ARG_STRING, &option_nodevice,
                        "Specify networking interface to ignore", "DEV" },
        { "plugin", 'p', 0, G_OPTION_ARG_STRING, &option_plugin,
                                "Specify plugins to load", "NAME,..." },
        { "noplugin", 'P', 0, G_OPTION_ARG_STRING, &option_noplugin,
                                "Specify plugins not to load", "NAME,..." },
        { "wifi", 'W', 0, G_OPTION_ARG_STRING, &option_wifi,
                                "Specify driver for WiFi/Supplicant", "NAME" },
        { "nodaemon", 'n', G_OPTION_FLAG_REVERSE,
                                G_OPTION_ARG_NONE, &option_detach,
                                "Don't fork daemon to background" },
        { "nodnsproxy", 'r', G_OPTION_FLAG_REVERSE,
                                G_OPTION_ARG_NONE, &option_dnsproxy,
                                "Don't enable DNS Proxy" },
        { "compat", 'c', 0, G_OPTION_ARG_NONE, &option_compat,
                                "(obsolete)" },
        { "version", 'v', 0, G_OPTION_ARG_NONE, &option_version,
                                "Show version information and exit" },
        { NULL },
};

建立结构体之后，创建context，将context与GOptionEntry关联，然后将命令行参数传入到context进行分析

        context = g_option_context_new(NULL);
        g_option_context_add_main_entries(context, options, NULL);

        if (g_option_context_parse(context, &argc, &argv, &error) == FALSE) {
                if (error != NULL) {
                        g_printerr("%s\n", error->message);
                        g_error_free(error);
                } else
                        g_printerr("An unknown error occurred\n");
                exit(1);
        }

最后，分析的过程会将GOptionEntry结构体定义的options中的各个标记进行相应的处理