C++ wcstring::substr方法代码示例

void tokenize_variable_array( const wcstring &val, std::vector<wcstring> &out)
{
    size_t pos = 0, end = val.size();
    while (pos < end) {
        size_t next_pos = val.find(ARRAY_SEP, pos);
        if (next_pos == wcstring::npos) break;
        out.push_back(val.substr(pos, next_pos - pos));
        pos = next_pos + 1; //skip the separator
    }
    out.push_back(val.substr(pos, end - pos));
}

// Dump a parse tree node in a form helpful to someone debugging the behavior of this program.
static void dump_node(indent_t node_indent, const parse_node_t &node, const wcstring &source) {
    wchar_t nextc = L' ';
    wchar_t prevc = L' ';
    wcstring source_txt = L"";
    if (node.source_start != SOURCE_OFFSET_INVALID && node.source_length != SOURCE_OFFSET_INVALID) {
        int nextc_idx = node.source_start + node.source_length;
        if ((size_t)nextc_idx < source.size()) {
            nextc = source[node.source_start + node.source_length];
        }
        if (node.source_start > 0) prevc = source[node.source_start - 1];
        source_txt = source.substr(node.source_start, node.source_length);
    }
    wchar_t prevc_str[4] = {prevc, 0, 0, 0};
    wchar_t nextc_str[4] = {nextc, 0, 0, 0};
    if (prevc < L' ') {
        prevc_str[0] = L'\\';
        prevc_str[1] = L'c';
        prevc_str[2] = prevc + '@';
    }
    if (nextc < L' ') {
        nextc_str[0] = L'\\';
        nextc_str[1] = L'c';
        nextc_str[2] = nextc + '@';
    }
    fwprintf(stderr, L"{off %4u, len %4u, indent %2u, kw %ls, %ls} [%ls|%ls|%ls]\n",
             node.source_start, node.source_length, node_indent, keyword_description(node.keyword),
             token_type_description(node.type), prevc_str, source_txt.c_str(), nextc_str);
}

/**
   Attempts tilde expansion of the string specified, modifying it in place.
*/
static void expand_home_directory(wcstring &input)
{
    const wchar_t * const in = input.c_str();
    if (in[0] == HOME_DIRECTORY)
    {
        int tilde_error = 0;
        size_t tail_idx;
        wcstring home;

        if (in[1] == '/' || in[1] == '\0')
        {
            /* Current users home directory */

            home = env_get_string(L"HOME");
            tail_idx = 1;
        }
        else
        {
            /* Some other users home directory */
            const wchar_t *name_end = wcschr(in, L'/');
            if (name_end)
            {
                tail_idx = name_end - in;
            }
            else
            {
                tail_idx = wcslen(in);
            }
            wcstring name_str = input.substr(1, tail_idx - 1);
            std::string name_cstr = wcs2string(name_str);
            struct passwd *userinfo = getpwnam(name_cstr.c_str());

            if (userinfo == NULL)
            {
                tilde_error = 1;
                input[0] = L'~';
            }
            else
            {
                home = str2wcstring(userinfo->pw_dir);
            }
        }

        if (! tilde_error)
        {
            input.replace(input.begin(), input.begin() + tail_idx, home);
        }
    }
}

int wildcard_expand_string(const wcstring &wc, const wcstring &working_directory,
                           expand_flags_t flags, std::vector<completion_t> *output) {
    assert(output != NULL);
    // Fuzzy matching only if we're doing completions.
    assert(flags.get(expand_flag::for_completions) || !flags.get(expand_flag::fuzzy_match));

    // expand_flag::special_for_cd requires expand_flag::directories_only and
    // expand_flag::for_completions and expand_flag::no_descriptions.
    assert(!(flags.get(expand_flag::special_for_cd)) ||
           ((flags.get(expand_flag::directories_only)) &&
            (flags.get(expand_flag::for_completions)) &&
            (flags.get(expand_flag::no_descriptions))));

    // Hackish fix for issue #1631. We are about to call c_str(), which will produce a string
    // truncated at any embedded nulls. We could fix this by passing around the size, etc. However
    // embedded nulls are never allowed in a filename, so we just check for them and return 0 (no
    // matches) if there is an embedded null.
    if (wc.find(L'\0') != wcstring::npos) {
        return 0;
    }

    // Compute the prefix and base dir. The prefix is what we prepend for filesystem operations
    // (i.e. the working directory), the base_dir is the part of the wildcard consumed thus far,
    // which we also have to append. The difference is that the base_dir is returned as part of the
    // expansion, and the prefix is not.
    //
    // Check for a leading slash. If we find one, we have an absolute path: the prefix is empty, the
    // base dir is /, and the wildcard is the remainder. If we don't find one, the prefix is the
    // working directory, the base dir is empty.
    wcstring prefix = L"", base_dir = L"", effective_wc;
    if (string_prefixes_string(L"/", wc)) {
        base_dir = L"/";
        effective_wc = wc.substr(1);
    } else {
        prefix = working_directory;
        effective_wc = wc;
    }

    wildcard_expander_t expander(prefix, flags, output);
    expander.expand(base_dir, effective_wc.c_str(), base_dir);
    return expander.status_code();
}

// Dump a parse tree node in a form helpful to someone debugging the behavior of this program.
static void dump_node(indent_t node_indent, const parse_node_t &node, const wcstring &source)
{
    int nextc_idx = node.source_start + node.source_length;
    wchar_t prevc = node.source_start > 0 ? source[node.source_start - 1] : L' ';
    wchar_t nextc = nextc_idx < source.size() ? source[nextc_idx] : L' ';
    wchar_t prevc_str[4] = {prevc, 0, 0, 0};
    wchar_t nextc_str[4] = {nextc, 0, 0, 0};
    if (prevc < L' ')
    {
        prevc_str[0] = L'\\';
        prevc_str[1] = L'c';
        prevc_str[2] = prevc + '@';
    }
    if (nextc < L' ')
    {
        nextc_str[0] = L'\\';
        nextc_str[1] = L'c';
        nextc_str[2] = nextc + '@';
    }
    fwprintf(stderr, L"{off %4d, len %4d, indent %2u, kw %ls, %ls} [%ls|%ls|%ls]\n",
            node.source_start, node.source_length, node_indent,
            keyword_description(node.keyword), token_type_description(node.type),
            prevc_str, source.substr(node.source_start, node.source_length).c_str(), nextc_str);
}

void env_init(const struct config_paths_t *paths /* or NULL */)
{
    /*
      env_read_only variables can not be altered directly by the user
    */

    const wchar_t * const ro_keys[] =
    {
        L"status",
        L"history",
        L"version",
        L"_",
        L"LINES",
        L"COLUMNS",
        L"PWD",
        //L"SHLVL", // will be inserted a bit lower down
        L"FISH_VERSION",
    };
    for (size_t i=0; i < sizeof ro_keys / sizeof *ro_keys; i++)
    {
        env_read_only.insert(ro_keys[i]);
    }

    /*
       Names of all dynamically calculated variables
       */
    env_electric.insert(L"history");
    env_electric.insert(L"status");
    env_electric.insert(L"umask");
    env_electric.insert(L"COLUMNS");
    env_electric.insert(L"LINES");

    top = new env_node_t;
    global_env = top;
    global = &top->env;

    /*
      Now the environemnt variable handling is set up, the next step
      is to insert valid data
    */

    /*
      Import environment variables
    */
    for (char **p = (environ ? environ : __environ); p && *p; p++)
    {
        const wcstring key_and_val = str2wcstring(*p); //like foo=bar
        size_t eql = key_and_val.find(L'=');
        if (eql == wcstring::npos)
        {
            // no equals found
            if (is_read_only(key_and_val) || is_electric(key_and_val)) continue;
            env_set(key_and_val, L"", ENV_EXPORT | ENV_GLOBAL);
        }
        else
        {
            wcstring key = key_and_val.substr(0, eql);
            if (is_read_only(key) || is_electric(key)) continue;
            wcstring val = key_and_val.substr(eql + 1);
            if (variable_is_colon_delimited_array(key))
            {
                std::replace(val.begin(), val.end(), L':', ARRAY_SEP);
            }

            env_set(key, val.c_str(), ENV_EXPORT | ENV_GLOBAL);
        }
    }

    /* Set the given paths in the environment, if we have any */
    if (paths != NULL)
    {
        env_set(FISH_DATADIR_VAR, paths->data.c_str(), ENV_GLOBAL);
        env_set(FISH_SYSCONFDIR_VAR, paths->sysconf.c_str(), ENV_GLOBAL);
        env_set(FISH_HELPDIR_VAR, paths->doc.c_str(), ENV_GLOBAL);
        env_set(FISH_BIN_DIR, paths->bin.c_str(), ENV_GLOBAL);
    }

    /*
      Set up the PATH variable
    */
    setup_path();

    /*
      Set up the USER variable
    */
    if (env_get_string(L"USER").missing_or_empty())
    {
        const struct passwd *pw = getpwuid(getuid());
        if (pw && pw->pw_name)
        {
            const wcstring uname = str2wcstring(pw->pw_name);
            env_set(L"USER", uname.c_str(), ENV_GLOBAL | ENV_EXPORT);
        }
    }

    /*
      Set up the version variables
    */
    wcstring version = str2wcstring(get_fish_version());
    env_set(L"version", version.c_str(), ENV_GLOBAL);
//.........这里部分代码省略.........

void env_init(const struct config_paths_t *paths /* or NULL */)
{
    /*
      env_read_only variables can not be altered directly by the user
    */

    const wchar_t * const ro_keys[] =
    {
        L"status",
        L"history",
        L"version",
        L"_",
        L"LINES",
        L"COLUMNS",
        L"PWD",
        L"SHLVL",
        L"FISH_VERSION",
    };
    for (size_t i=0; i < sizeof ro_keys / sizeof *ro_keys; i++)
    {
        env_read_only.insert(ro_keys[i]);
    }

    /*
      HOME and USER should be writeable by root, since this can be a
      convenient way to install software.
    */
    if (getuid() != 0)
    {
        env_read_only.insert(L"HOME");
        env_read_only.insert(L"USER");
    }

    /*
       Names of all dynamically calculated variables
       */
    env_electric.insert(L"history");
    env_electric.insert(L"status");
    env_electric.insert(L"umask");

    top = new env_node_t;
    global_env = top;
    global = &top->env;

    /*
      Now the environemnt variable handling is set up, the next step
      is to insert valid data
    */

    /*
      Import environment variables
    */
    for (char **p = (environ ? environ : __environ); p && *p; p++)
    {
        const wcstring key_and_val = str2wcstring(*p); //like foo=bar
        size_t eql = key_and_val.find(L'=');
        if (eql == wcstring::npos)
        {
            // no equals found
            env_set(key_and_val, L"", ENV_EXPORT);
        }
        else
        {
            wcstring key = key_and_val.substr(0, eql);
            wcstring val = key_and_val.substr(eql + 1);
            if (variable_can_be_array(val))
            {
                std::replace(val.begin(), val.end(), L':', ARRAY_SEP);
            }

            env_set(key, val.c_str(), ENV_EXPORT | ENV_GLOBAL);
        }
    }

    /* Set the given paths in the environment, if we have any */
    if (paths != NULL)
    {
        env_set(FISH_DATADIR_VAR, paths->data.c_str(), ENV_GLOBAL | ENV_EXPORT);
        env_set(FISH_SYSCONFDIR_VAR, paths->sysconf.c_str(), ENV_GLOBAL | ENV_EXPORT);
        env_set(FISH_HELPDIR_VAR, paths->doc.c_str(), ENV_GLOBAL | ENV_EXPORT);
        env_set(FISH_BIN_DIR, paths->bin.c_str(), ENV_GLOBAL | ENV_EXPORT);
    }

    /*
      Set up the PATH variable
    */
    setup_path();

    /*
      Set up the USER variable
    */
    const struct passwd *pw = getpwuid(getuid());
    if (pw && pw->pw_name)
    {
        const wcstring uname = str2wcstring(pw->pw_name);
        env_set(L"USER", uname.c_str(), ENV_GLOBAL | ENV_EXPORT);
    }

    /*
      Set up the version variables
//.........这里部分代码省略.........

void s_write(screen_t *s, const wcstring &left_prompt, const wcstring &right_prompt,
             const wcstring &commandline, size_t explicit_len,
             const std::vector<highlight_spec_t> &colors, const std::vector<int> &indent,
             size_t cursor_pos, const page_rendering_t &pager, bool cursor_is_within_pager) {
    screen_data_t::cursor_t cursor_arr;

    // Turn the command line into the explicit portion and the autosuggestion.
    const wcstring explicit_command_line = commandline.substr(0, explicit_len);
    const wcstring autosuggestion = commandline.substr(explicit_len);

    // If we are using a dumb terminal, don't try any fancy stuff, just print out the text.
    // right_prompt not supported.
    if (is_dumb()) {
        const std::string prompt_narrow = wcs2string(left_prompt);
        const std::string command_line_narrow = wcs2string(explicit_command_line);

        write_loop(STDOUT_FILENO, "\r", 1);
        write_loop(STDOUT_FILENO, prompt_narrow.c_str(), prompt_narrow.size());
        write_loop(STDOUT_FILENO, command_line_narrow.c_str(), command_line_narrow.size());

        return;
    }

    s_check_status(s);
    const size_t screen_width = common_get_width();

    // Completely ignore impossibly small screens.
    if (screen_width < 4) {
        return;
    }

    // Compute a layout.
    const screen_layout_t layout = compute_layout(s, screen_width, left_prompt, right_prompt,
                                                  explicit_command_line, autosuggestion, indent);

    // Determine whether, if we have an autosuggestion, it was truncated.
    s->autosuggestion_is_truncated =
        !autosuggestion.empty() && autosuggestion != layout.autosuggestion;

    // Clear the desired screen.
    s->desired.resize(0);
    s->desired.cursor.x = s->desired.cursor.y = 0;

    // Append spaces for the left prompt.
    for (size_t i = 0; i < layout.left_prompt_space; i++) {
        s_desired_append_char(s, L' ', highlight_spec_t{}, 0, layout.left_prompt_space);
    }

    // If overflowing, give the prompt its own line to improve the situation.
    size_t first_line_prompt_space = layout.left_prompt_space;
    if (layout.prompts_get_own_line) {
        s_desired_append_char(s, L'\n', highlight_spec_t{}, 0, 0);
        first_line_prompt_space = 0;
    }

    // Reconstruct the command line.
    wcstring effective_commandline = explicit_command_line + layout.autosuggestion;

    // Output the command line.
    size_t i;
    for (i = 0; i < effective_commandline.size(); i++) {
        // Grab the current cursor's x,y position if this character matches the cursor's offset.
        if (!cursor_is_within_pager && i == cursor_pos) {
            cursor_arr = s->desired.cursor;
        }
        s_desired_append_char(s, effective_commandline.at(i), colors[i], indent[i],
                              first_line_prompt_space);
    }

    // Cursor may have been at the end too.
    if (!cursor_is_within_pager && i == cursor_pos) {
        cursor_arr = s->desired.cursor;
    }

    // Now that we've output everything, set the cursor to the position that we saved in the loop
    // above.
    s->desired.cursor = cursor_arr;

    if (cursor_is_within_pager) {
        s->desired.cursor.x = (int)cursor_pos;
        s->desired.cursor.y = (int)s->desired.line_count();
    }

    // Append pager_data (none if empty).
    s->desired.append_lines(pager.screen_data);

    s_update(s, layout.left_prompt, layout.right_prompt);
    s_save_status(s);
}

void s_write(screen_t *s,
             const wcstring &left_prompt,
             const wcstring &right_prompt,
             const wcstring &commandline,
             size_t explicit_len,
             const int *colors,
             const int *indent,
             size_t cursor_pos)
{
    screen_data_t::cursor_t cursor_arr;

    CHECK(s,);
    CHECK(indent,);

    /* Turn the command line into the explicit portion and the autosuggestion */
    const wcstring explicit_command_line = commandline.substr(0, explicit_len);
    const wcstring autosuggestion = commandline.substr(explicit_len);

    /*
      If we are using a dumb terminal, don't try any fancy stuff,
      just print out the text. right_prompt not supported.
     */
    if (is_dumb())
    {
        const std::string prompt_narrow = wcs2string(left_prompt);
        const std::string command_line_narrow = wcs2string(explicit_command_line);

        write_loop(STDOUT_FILENO, "\r", 1);
        write_loop(STDOUT_FILENO, prompt_narrow.c_str(), prompt_narrow.size());
        write_loop(STDOUT_FILENO, command_line_narrow.c_str(), command_line_narrow.size());

        return;
    }

    s_check_status(s);
    const size_t screen_width = common_get_width();

    /* Completely ignore impossibly small screens */
    if (screen_width < 4)
    {
        return;
    }

    /* Compute a layout */
    const screen_layout_t layout = compute_layout(s, screen_width, left_prompt, right_prompt, explicit_command_line, autosuggestion, indent);

    /* Determine whether, if we have an autosuggestion, it was truncated */
    s->autosuggestion_is_truncated = ! autosuggestion.empty() && autosuggestion != layout.autosuggestion;

    /* Clear the desired screen */
    s->desired.resize(0);
    s->desired.cursor.x = s->desired.cursor.y = 0;

    /* Append spaces for the left prompt */
    for (size_t i=0; i < layout.left_prompt_space; i++)
    {
        s_desired_append_char(s, L' ', 0, 0, layout.left_prompt_space);
    }

    /* If overflowing, give the prompt its own line to improve the situation. */
    size_t first_line_prompt_space = layout.left_prompt_space;
    if (layout.prompts_get_own_line)
    {
        s_desired_append_char(s, L'\n', 0, 0, 0);
        first_line_prompt_space = 0;
    }

    /* Reconstruct the command line */
    wcstring effective_commandline = explicit_command_line + layout.autosuggestion;

    /* Output the command line */
    size_t i;
    for (i=0; i < effective_commandline.size(); i++)
    {
        int color = colors[i];

        if (i == cursor_pos)
        {
            color = 0;
        }

        if (i == cursor_pos)
        {
            cursor_arr = s->desired.cursor;
        }

        s_desired_append_char(s, effective_commandline.at(i), color, indent[i], first_line_prompt_space);
    }
    if (i == cursor_pos)
    {
        cursor_arr = s->desired.cursor;
    }

    s->desired.cursor = cursor_arr;
    s_update(s, layout.left_prompt.c_str(), layout.right_prompt.c_str());
    s_save_status(s);
}

// Helper function to abstract the repeat until logic from string_repeat
// returns the to_repeat string, repeated until max char has been reached.
static wcstring wcsrepeat_until(const wcstring &to_repeat, size_t max) {
    size_t count = max / to_repeat.length();
    size_t mod = max % to_repeat.length();

    return wcsrepeat(to_repeat, count) + to_repeat.substr(0, mod);
}