C++ env_var_t类代码示例

static wcstring path_create_data() {
    bool done = false;
    wcstring res;

    const env_var_t xdg_dir = env_get_string(L"XDG_DATA_HOME");
    if (!xdg_dir.missing()) {
        res = xdg_dir + L"/fish";
        if (!create_directory(res)) {
            done = true;
        }
    } else {
        const env_var_t home = env_get_string(L"HOME");
        if (!home.missing()) {
            res = home + L"/.local/share/fish";
            if (!create_directory(res)) {
                done = true;
            }
        }
    }

    if (!done) {
        res.clear();

        debug(0, _(L"Unable to create a data directory for fish. Your history will not be saved. "
                   L"Please set the $XDG_DATA_HOME variable to a directory where the current user "
                   L"has write access."));
    }
    return res;
}

/// Make sure the PATH variable contains something.
static void setup_path() {
    const env_var_t path = env_get_string(L"PATH");
    if (path.missing_or_empty()) {
        const wchar_t *value = L"/usr/bin" ARRAY_SEP_STR L"/bin";
        env_set(L"PATH", value, ENV_GLOBAL | ENV_EXPORT);
    }
}

static void update_export_array_if_necessary(bool recalc) {
    ASSERT_IS_MAIN_THREAD();
    if (recalc && !get_proc_had_barrier()) {
        set_proc_had_barrier(true);
        env_universal_barrier();
    }

    if (has_changed_exported) {
        std::map<wcstring, wcstring> vals;

        debug(4, L"env_export_arr() recalc");

        get_exported(top, &vals);

        if (uvars()) {
            const wcstring_list_t uni = uvars()->get_names(true, false);
            for (size_t i = 0; i < uni.size(); i++) {
                const wcstring &key = uni.at(i);
                const env_var_t val = uvars()->get(key);

                if (!val.missing() && val != ENV_NULL) {
                    // Note that std::map::insert does NOT overwrite a value already in the map,
                    // which we depend on here.
                    vals.insert(std::pair<wcstring, wcstring>(key, val));
                }
            }
        }

        std::vector<std::string> local_export_buffer;
        export_func(vals, local_export_buffer);
        export_array.set(local_export_buffer);
        has_changed_exported = false;
    }
}

static wcstring path_create_config() {
    bool done = false;
    wcstring res;

    const env_var_t xdg_dir = env_get_string(L"XDG_CONFIG_HOME");
    if (!xdg_dir.missing()) {
        res = xdg_dir + L"/fish";
        if (!create_directory(res)) {
            done = true;
        }
    } else {
        const env_var_t home = env_get_string(L"HOME");
        if (!home.missing()) {
            res = home + L"/.config/fish";
            if (!create_directory(res)) {
                done = true;
            }
        }
    }

    if (!done) {
        res.clear();

        debug(0, _(L"Unable to create a configuration directory for fish. Your personal settings "
                   L"will not be saved. Please set the $XDG_CONFIG_HOME variable to a directory "
                   L"where the current user has write access."));
    }
    return res;
}

/// Properly sets all locale information.
static void handle_locale(const wchar_t *env_var_name) {
    debug(2, L"handle_locale() called in response to '%ls' changing", env_var_name);
    const char *old_msg_locale = setlocale(LC_MESSAGES, NULL);
    const env_var_t val = env_get_string(env_var_name, ENV_EXPORT);
    const std::string &value = wcs2string(val);
    const std::string &name = wcs2string(env_var_name);
    debug(2, L"locale var %s='%s'", name.c_str(), value.c_str());
    if (val.empty()) {
        unsetenv(name.c_str());
    } else {
        setenv(name.c_str(), value.c_str(), 1);
    }

    char *locale = setlocale(LC_ALL, "");
    fish_setlocale();
    debug(2, L"handle_locale() setlocale(): '%s'", locale);

    const char *new_msg_locale = setlocale(LC_MESSAGES, NULL);
    debug(3, L"old LC_MESSAGES locale: '%s'", old_msg_locale);
    debug(3, L"new LC_MESSAGES locale: '%s'", new_msg_locale);
#ifdef HAVE__NL_MSG_CAT_CNTR
    if (strcmp(old_msg_locale, new_msg_locale)) {
        // Make change known to GNU gettext.
        extern int _nl_msg_cat_cntr;
        _nl_msg_cat_cntr++;
    }
#endif
}

/**
   When fishd isn't started, this function is provided to
   env_universal as a callback, it tries to start up fishd. It's
   implementation is a bit of a hack, since it evaluates a bit of
   shellscript, and it might be used at times when that might not be
   the best idea.
*/
static void start_fishd()
{
    struct passwd *pw = getpwuid(getuid());

    debug(3, L"Spawning new copy of fishd");

    if (!pw)
    {
        debug(0, _(L"Could not get user information"));
        return;
    }

    wcstring cmd = format_string(FISHD_CMD, pw->pw_name);

    /* Prefer the fishd in __fish_bin_dir, if exists */
    const env_var_t bin_dir = env_get_string(L"__fish_bin_dir");
    if (! bin_dir.missing_or_empty())
    {
        wcstring path = bin_dir + L"/fishd";
        if (waccess(path, X_OK) == 0)
        {
            /* The path command just looks like 'fishd', so insert the bin path to make it absolute */
            cmd.insert(0, bin_dir + L"/");
        }
    }
    parser_t &parser = parser_t::principal_parser();
    parser.eval(cmd, io_chain_t(), TOP);
}

/**
   Set up default values for various variables if not defined.
 */
static void env_set_defaults()
{

	if( env_get_string(L"USER").missing() )
	{
		struct passwd *pw = getpwuid( getuid());
		wchar_t *unam = str2wcs( pw->pw_name );
		env_set( L"USER", unam, ENV_GLOBAL );
		free( unam );
	}

	if( env_get_string(L"HOME").missing() )
	{
		const env_var_t unam = env_get_string( L"USER" );
		char *unam_narrow = wcs2str( unam.c_str() );
		struct passwd *pw = getpwnam( unam_narrow );
		wchar_t *dir = str2wcs( pw->pw_dir );
		env_set( L"HOME", dir, ENV_GLOBAL );
		free( dir );		
		free( unam_narrow );
	}	

	env_set_pwd();
	
}

/**
   Set up default values for various variables if not defined.
 */
static void env_set_defaults()
{

    if (env_get_string(L"USER").missing())
    {
        struct passwd *pw = getpwuid(getuid());
        if (pw->pw_name != NULL)
        {
            const wcstring wide_name = str2wcstring(pw->pw_name);
            env_set(L"USER", wide_name.c_str(), ENV_GLOBAL);
        }
    }

    if (env_get_string(L"HOME").missing())
    {
        const env_var_t unam = env_get_string(L"USER");
        char *unam_narrow = wcs2str(unam.c_str());
        struct passwd *pw = getpwnam(unam_narrow);
        if (pw->pw_dir != NULL)
        {
            const wcstring dir = str2wcstring(pw->pw_dir);
            env_set(L"HOME", dir.c_str(), ENV_GLOBAL);
        }
        free(unam_narrow);
    }

    env_set_pwd();

}

/// Insert a list of all dynamically loaded functions into the specified list.
static void autoload_names(std::set<wcstring> &names, int get_hidden) {
    size_t i;

    const env_var_t path_var_wstr = env_get_string(L"fish_function_path");
    if (path_var_wstr.missing()) return;
    const wchar_t *path_var = path_var_wstr.c_str();

    wcstring_list_t path_list;

    tokenize_variable_array(path_var, path_list);
    for (i = 0; i < path_list.size(); i++) {
        const wcstring &ndir_str = path_list.at(i);
        const wchar_t *ndir = (wchar_t *)ndir_str.c_str();
        DIR *dir = wopendir(ndir);
        if (!dir) continue;

        wcstring name;
        while (wreaddir(dir, name)) {
            const wchar_t *fn = name.c_str();
            const wchar_t *suffix;
            if (!get_hidden && fn[0] == L'_') continue;

            suffix = wcsrchr(fn, L'.');
            if (suffix && (wcscmp(suffix, L".fish") == 0)) {
                wcstring name(fn, suffix - fn);
                names.insert(name);
            }
        }
        closedir(dir);
    }
}

bool autoload_t::can_load(const wcstring &cmd, const env_vars_snapshot_t &vars) {
    const env_var_t path_var = vars.get(env_var_name);
    if (path_var.missing_or_empty()) return false;

    std::vector<wcstring> path_list;
    tokenize_variable_array(path_var, path_list);
    return this->locate_file_and_maybe_load_it(cmd, false, false, path_list);
}

void kill_add(const wcstring &str)
{
    ASSERT_IS_MAIN_THREAD();
    if (str.empty())
        return;

    wcstring cmd;
    wcstring escaped_str;
    kill_list.push_front(str);

    /*
       Check to see if user has set the FISH_CLIPBOARD_CMD variable,
       and, if so, use it instead of checking the display, etc.

       I couldn't think of a safe way to allow overide of the echo
       command too, so, the command used must accept the input via stdin.
    */

    const env_var_t clipboard_wstr = env_get_string(L"FISH_CLIPBOARD_CMD");
    if (!clipboard_wstr.missing())
    {
        escaped_str = escape(str.c_str(), ESCAPE_ALL);
        cmd.assign(L"echo -n ");
        cmd.append(escaped_str);
        cmd.append(clipboard_wstr);
    }
    else
    {
        /* This is for sending the kill to the X copy-and-paste buffer */
        if (!has_xsel())
        {
            return;
        }

        const env_var_t disp_wstr = env_get_string(L"DISPLAY");
        if (!disp_wstr.missing())
        {
            escaped_str = escape(str.c_str(), ESCAPE_ALL);
            cmd.assign(L"echo -n ");
            cmd.append(escaped_str);
            cmd.append(L" | xsel -i -b");
        }
    }

    if (! cmd.empty())
    {
        if (exec_subshell(cmd, false /* do not apply exit status */) == -1)
        {
            /*
               Do nothing on failiure
            */
        }

        cut_buffer = escaped_str;
    }
}

env_vars_snapshot_t::env_vars_snapshot_t(const wchar_t *const *keys) {
    ASSERT_IS_MAIN_THREAD();
    wcstring key;
    for (size_t i = 0; keys[i]; i++) {
        key.assign(keys[i]);
        const env_var_t val = env_get_string(key);
        if (!val.missing()) {
            vars[key] = val;
        }
    }
}

/// Properly sets all timezone information.
static void handle_timezone(const wchar_t *env_var_name) {
    debug(2, L"handle_timezone() called in response to '%ls' changing", env_var_name);
    const env_var_t val = env_get_string(env_var_name, ENV_EXPORT);
    const std::string &value = wcs2string(val);
    const std::string &name = wcs2string(env_var_name);
    debug(2, L"timezone var %s='%s'", name.c_str(), value.c_str());
    if (val.empty()) {
        unsetenv(name.c_str());
    } else {
        setenv(name.c_str(), value.c_str(), 1);
    }
    tzset();
}

/// Push all curses/terminfo env vars into the global environment where they can be found by those
/// libraries.
static void handle_curses(const wchar_t *env_var_name) {
    debug(2, L"handle_curses() called in response to '%ls' changing", env_var_name);
    const env_var_t val = env_get_string(env_var_name, ENV_EXPORT);
    const std::string &name = wcs2string(env_var_name);
    const std::string &value = wcs2string(val);
    debug(2, L"curses var %s='%s'", name.c_str(), value.c_str());
    if (val.empty()) {
        unsetenv(name.c_str());
    } else {
        setenv(name.c_str(), value.c_str(), 1);
    }
    // TODO: Modify input_init() to allow calling it when the terminfo env vars are dynamically
    // changed. At the present time it can be called just once. Also, we should really only do this
    // if the TERM var is set.
    // input_init();
}

wcstring expand_escape_variable(const env_var_t &var) {
    wcstring buff;
    wcstring_list_t lst;

    var.to_list(lst);
    if (lst.size() == 0) {
        ;  // empty list expands to nothing
    } else if (lst.size() == 1) {
        const wcstring &el = lst.at(0);

        if (el.find(L' ') != wcstring::npos && is_quotable(el)) {
            buff.append(L"'");
            buff.append(el);
            buff.append(L"'");
        } else {
            buff.append(escape_string(el, 1));
        }
    } else {
        for (size_t j = 0; j < lst.size(); j++) {
            const wcstring &el = lst.at(j);
            if (j) buff.append(L"  ");

            if (is_quotable(el)) {
                buff.append(L"'");
                buff.append(el);
                buff.append(L"'");
            } else {
                buff.append(escape_string(el, 1));
            }
        }
    }

    return buff;
}