C++ wcstring::c_str方法代码示例

bool wildcard_match(const wcstring &str, const wcstring &wc, bool leading_dots_fail_to_match)
{
    return wildcard_match_internal(str.c_str(), wc.c_str(), leading_dots_fail_to_match, true /* first */);
}

static bool is_read_only(const wcstring &key)
{
    return env_read_only.find(key.c_str()) != env_read_only.end();
}

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_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
    */
    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.........

int job_reap(bool allow_interactive) {
    ASSERT_IS_MAIN_THREAD();
    job_t *jnext;
    int found = 0;

    // job_reap may fire an event handler, we do not want to call ourselves recursively (to avoid
    // infinite recursion).
    static bool locked = false;
    if (locked) {
        return 0;
    }
    locked = true;

    // this may be invoked in an exit handler, after the TERM has been torn down
    // don't try to print in that case (#3222)
    const bool interactive = allow_interactive && cur_term != NULL;

    process_mark_finished_children(false);

    // Preserve the exit status.
    const int saved_status = proc_get_last_status();

    job_iterator_t jobs;
    const size_t job_count = jobs.count();
    jnext = jobs.next();
    while (jnext) {
        job_t *j = jnext;
        jnext = jobs.next();

        // If we are reaping only jobs who do not need status messages sent to the console, do not
        // consider reaping jobs that need status messages.
        if ((!job_get_flag(j, JOB_SKIP_NOTIFICATION)) && (!interactive) &&
            (!job_get_flag(j, JOB_FOREGROUND))) {
            continue;
        }

        for (process_t *p = j->first_process; p; p = p->next) {
            int s;
            if (!p->completed) continue;

            if (!p->pid) continue;

            s = p->status;

            proc_fire_event(L"PROCESS_EXIT", EVENT_EXIT, p->pid,
                            (WIFSIGNALED(s) ? -1 : WEXITSTATUS(s)));

            // Ignore signal SIGPIPE.We issue it ourselves to the pipe writer when the pipe reader
            // dies.
            if (!WIFSIGNALED(s) || WTERMSIG(s) == SIGPIPE) {
                continue;
            }

            // Handle signals other than SIGPIPE.
            int proc_is_job = ((p == j->first_process) && (p->next == 0));
            if (proc_is_job) job_set_flag(j, JOB_NOTIFIED, 1);
            if (job_get_flag(j, JOB_SKIP_NOTIFICATION)) {
                continue;
            }

            // Print nothing if we get SIGINT in the foreground process group, to avoid spamming
            // obvious stuff on the console (#1119). If we get SIGINT for the foreground
            // process, assume the user typed ^C and can see it working. It's possible they
            // didn't, and the signal was delivered via pkill, etc., but the SIGINT/SIGTERM
            // distinction is precisely to allow INT to be from a UI
            // and TERM to be programmatic, so this assumption is keeping with the design of
            // signals. If echoctl is on, then the terminal will have written ^C to the console.
            // If off, it won't have. We don't echo ^C either way, so as to respect the user's
            // preference.
            if (WTERMSIG(p->status) != SIGINT || !job_get_flag(j, JOB_FOREGROUND)) {
                if (proc_is_job) {
                    // We want to report the job number, unless it's the only job, in which case
                    // we don't need to.
                    const wcstring job_number_desc =
                        (job_count == 1) ? wcstring() : format_string(L"Job %d, ", j->job_id);
                    fwprintf(stdout, _(L"%ls: %ls\'%ls\' terminated by signal %ls (%ls)"),
                             program_name, job_number_desc.c_str(),
                             truncate_command(j->command()).c_str(), sig2wcs(WTERMSIG(p->status)),
                             signal_get_desc(WTERMSIG(p->status)));
                } else {
                    const wcstring job_number_desc =
                        (job_count == 1) ? wcstring() : format_string(L"from job %d, ", j->job_id);
                    fwprintf(stdout, _(L"%ls: Process %d, \'%ls\' %ls\'%ls\' "
                                       L"terminated by signal %ls (%ls)"),
                             program_name, p->pid, p->argv0(), job_number_desc.c_str(),
                             truncate_command(j->command()).c_str(), sig2wcs(WTERMSIG(p->status)),
                             signal_get_desc(WTERMSIG(p->status)));
                }

                if (cur_term != NULL) {
                    tputs(clr_eol, 1, &writeb);
                } else {
                    fwprintf(stdout, L"\x1b[K");  // no term set up - do clr_eol manually
                }
                fwprintf(stdout, L"\n");
            }
            found = 1;
            p->status = 0;  // clear status so it is not reported more than once
        }

//.........这里部分代码省略.........

void parse_util_get_parameter_info(const wcstring &cmd, const size_t pos, wchar_t *quote, size_t *offset, int *type)
{
    size_t prev_pos=0;
    wchar_t last_quote = '\0';
    int unfinished;

    tokenizer_t tok(cmd.c_str(), TOK_ACCEPT_UNFINISHED | TOK_SQUASH_ERRORS);
    for (; tok_has_next(&tok); tok_next(&tok))
    {
        if (tok_get_pos(&tok) > pos)
            break;

        if (tok_last_type(&tok) == TOK_STRING)
            last_quote = get_quote(tok_last(&tok),
                                   pos - tok_get_pos(&tok));

        if (type != NULL)
            *type = tok_last_type(&tok);

        prev_pos = tok_get_pos(&tok);
    }

    wchar_t *cmd_tmp = wcsdup(cmd.c_str());
    cmd_tmp[pos]=0;
    size_t cmdlen = wcslen(cmd_tmp);
    unfinished = (cmdlen==0);
    if (!unfinished)
    {
        unfinished = (quote != 0);

        if (!unfinished)
        {
            if (wcschr(L" \t\n\r", cmd_tmp[cmdlen-1]) != 0)
            {
                if ((cmdlen == 1) || (cmd_tmp[cmdlen-2] != L'\\'))
                {
                    unfinished=1;
                }
            }
        }
    }

    if (quote)
        *quote = last_quote;

    if (offset != 0)
    {
        if (!unfinished)
        {
            while ((cmd_tmp[prev_pos] != 0) && (wcschr(L";|",cmd_tmp[prev_pos])!= 0))
                prev_pos++;

            *offset = prev_pos;
        }
        else
        {
            *offset = pos;
        }
    }
    free(cmd_tmp);
}

static screen_layout_t compute_layout(screen_t *s,
                                      size_t screen_width,
                                      const wcstring &left_prompt_str,
                                      const wcstring &right_prompt_str,
                                      const wcstring &commandline,
                                      const wcstring &autosuggestion_str,
                                      const int *indent)
{
    screen_layout_t result = {};

    /* Start by ensuring that the prompts themselves can fit */
    const wchar_t *left_prompt = left_prompt_str.c_str();
    const wchar_t *right_prompt = right_prompt_str.c_str();
    const wchar_t *autosuggestion = autosuggestion_str.c_str();

    prompt_layout_t left_prompt_layout = calc_prompt_layout(left_prompt);
    prompt_layout_t right_prompt_layout = calc_prompt_layout(right_prompt);

    size_t left_prompt_width = left_prompt_layout.last_line_width;
    size_t right_prompt_width = right_prompt_layout.last_line_width;

    if (left_prompt_layout.max_line_width > screen_width)
    {
        /* If we have a multi-line prompt, see if the longest line fits; if not neuter the whole left prompt */
        left_prompt = L"> ";
        left_prompt_width = 2;
    }

    if (left_prompt_width + right_prompt_width >= screen_width)
    {
        /* Nix right_prompt */
        right_prompt = L"";
        right_prompt_width = 0;
    }

    if (left_prompt_width + right_prompt_width >= screen_width)
    {
        /* Still doesn't fit, neuter left_prompt */
        left_prompt = L"> ";
        left_prompt_width = 2;
    }

    /* Now we should definitely fit */
    assert(left_prompt_width + right_prompt_width < screen_width);


    /* Convert commandline to a list of lines and their widths */
    wcstring_list_t command_lines(1);
    std::vector<size_t> line_widths(1);
    for (size_t i=0; i < commandline.size(); i++)
    {
        wchar_t c = commandline.at(i);
        if (c == L'\n')
        {
            /* Make a new line */
            command_lines.push_back(wcstring());
            line_widths.push_back(indent[i]*INDENT_STEP);
        }
        else
        {
            command_lines.back() += c;
            line_widths.back() += fish_wcwidth_min_0(c);
        }
    }
    const size_t first_command_line_width = line_widths.at(0);

    /* If we have more than one line, ensure we have no autosuggestion */
    if (command_lines.size() > 1)
    {
        autosuggestion = L"";
    }

    /* Compute the width of the autosuggestion at all possible truncation offsets */
    std::vector<size_t> autosuggestion_truncated_widths;
    autosuggestion_truncated_widths.reserve(1 + wcslen(autosuggestion));
    size_t autosuggestion_total_width = 0;
    for (size_t i=0; autosuggestion[i] != L'\0'; i++)
    {
        autosuggestion_truncated_widths.push_back(autosuggestion_total_width);
        autosuggestion_total_width += fish_wcwidth_min_0(autosuggestion[i]);
    }

    /* Here are the layouts we try in turn:

    1. Left prompt visible, right prompt visible, command line visible, autosuggestion visible
    2. Left prompt visible, right prompt visible, command line visible, autosuggestion truncated (possibly to zero)
    3. Left prompt visible, right prompt hidden, command line visible, autosuggestion hidden
    4. Newline separator (left prompt visible, right prompt hidden, command line visible, autosuggestion visible)

    A remark about layout #4: if we've pushed the command line to a new line, why can't we draw the right prompt? The issue is resizing: if you resize the window smaller, then the right prompt will wrap to the next line. This means that we can't go back to the line that we were on, and things turn to chaos very quickly.

    */

    bool done = false;

    /* Case 1 */
    if (! done && left_prompt_width + right_prompt_width + first_command_line_width + autosuggestion_total_width < screen_width)
    {
        result.left_prompt = left_prompt;
        result.left_prompt_space = left_prompt_width;
//.........这里部分代码省略.........

//.........这里部分代码省略.........
                    return COMPLETE_DIRECTORY_SYMLINK_DESC;
                }
                else
                {

                    if ((buf.st_mode & S_IXUSR) ||
                            (buf.st_mode & S_IXGRP) ||
                            (buf.st_mode & S_IXOTH))
                    {

                        if (waccess(filename, X_OK) == 0)
                        {
                            /*
                              Weird group permissions and other such
                              issues make it non-trivial to find out
                              if we can actually execute a file using
                              the result from stat. It is much safer
                              to use the access function, since it
                              tells us exactly what we want to know.
                            */
                            return COMPLETE_EXEC_LINK_DESC;
                        }
                    }
                }

                return COMPLETE_SYMLINK_DESC;

            }
            else
            {
                switch (err)
                {
                    case ENOENT:
                    {
                        return COMPLETE_ROTTEN_SYMLINK_DESC;
                    }

                    case ELOOP:
                    {
                        return COMPLETE_LOOP_SYMLINK_DESC;
                    }
                }
                /*
                  On unknown errors we do nothing. The file will be
                  given the default 'File' description or one based on the suffix.
                */
            }

        }
        else if (S_ISCHR(buf.st_mode))
        {
            return COMPLETE_CHAR_DESC;
        }
        else if (S_ISBLK(buf.st_mode))
        {
            return COMPLETE_BLOCK_DESC;
        }
        else if (S_ISFIFO(buf.st_mode))
        {
            return COMPLETE_FIFO_DESC;
        }
        else if (S_ISSOCK(buf.st_mode))
        {
            return COMPLETE_SOCKET_DESC;
        }
        else if (S_ISDIR(buf.st_mode))
        {
            return COMPLETE_DIRECTORY_DESC;
        }
        else
        {
            if ((buf.st_mode & S_IXUSR) ||
                    (buf.st_mode & S_IXGRP) ||
                    (buf.st_mode & S_IXOTH))
            {

                if (waccess(filename, X_OK) == 0)
                {
                    /*
                      Weird group permissions and other such issues
                      make it non-trivial to find out if we can
                      actually execute a file using the result from
                      stat. It is much safer to use the access
                      function, since it tells us exactly what we want
                      to know.
                    */
                    return COMPLETE_EXEC_DESC;
                }
            }
        }
    }

    suffix = wcsrchr(filename.c_str(), L'.');
    if (suffix != 0 && !wcsrchr(suffix, L'/'))
    {
        return complete_get_desc_suffix(suffix);
    }

    return COMPLETE_FILE_DESC ;
}

static int is_quotable(const wcstring &str) { return is_quotable(str.c_str()); }

/// Expand all environment variables in the string *ptr.
///
/// This function is slow, fragile and complicated. There are lots of little corner cases, like
/// $$foo should do a double expansion, $foo$bar should not double expand bar, etc. Also, it's easy
/// to accidentally leak memory on array out of bounds errors an various other situations. All in
/// all, this function should be rewritten, split out into multiple logical units and carefully
/// tested. After that, it can probably be optimized to do fewer memory allocations, fewer string
/// scans and overall just less work. But until that happens, don't edit it unless you know exactly
/// what you are doing, and do proper testing afterwards.
///
/// This function operates on strings backwards, starting at last_idx.
///
/// Note: last_idx is considered to be where it previously finished procesisng. This means it
/// actually starts operating on last_idx-1. As such, to process a string fully, pass string.size()
/// as last_idx instead of string.size()-1.
static bool expand_variables(const wcstring &instr, std::vector<completion_t> *out, size_t last_idx,
                             parse_error_list_t *errors) {
    const size_t insize = instr.size();

    // last_idx may be 1 past the end of the string, but no further.
    assert(last_idx <= insize && "Invalid last_idx");
    if (last_idx == 0) {
        append_completion(out, instr);
        return true;
    }

    // Locate the last VARIABLE_EXPAND or VARIABLE_EXPAND_SINGLE
    bool is_single = false;
    size_t varexp_char_idx = last_idx;
    while (varexp_char_idx--) {
        const wchar_t c = instr.at(varexp_char_idx);
        if (c == VARIABLE_EXPAND || c == VARIABLE_EXPAND_SINGLE) {
            is_single = (c == VARIABLE_EXPAND_SINGLE);
            break;
        }
    }
    if (varexp_char_idx >= instr.size()) {
        // No variable expand char, we're done.
        append_completion(out, instr);
        return true;
    }

    // Get the variable name.
    const size_t var_name_start = varexp_char_idx + 1;
    size_t var_name_stop = var_name_start;
    while (var_name_stop < insize) {
        const wchar_t nc = instr.at(var_name_stop);
        if (nc == VARIABLE_EXPAND_EMPTY) {
            var_name_stop++;
            break;
        }
        if (!valid_var_name_char(nc)) break;
        var_name_stop++;
    }
    assert(var_name_stop >= var_name_start && "Bogus variable name indexes");
    const size_t var_name_len = var_name_stop - var_name_start;

    // It's an error if the name is empty.
    if (var_name_len == 0) {
        if (errors) {
            parse_util_expand_variable_error(instr, 0 /* global_token_pos */, varexp_char_idx,
                                             errors);
        }
        return false;
    }

    // Get the variable name as a string, then try to get the variable from env.
    const wcstring var_name(instr, var_name_start, var_name_len);
    // Do a dirty hack to make sliced history fast (#4650). We expand from either a variable, or a
    // history_t. Note that "history" is read only in env.cpp so it's safe to special-case it in
    // this way (it cannot be shadowed, etc).
    history_t *history = nullptr;
    maybe_t<env_var_t> var{};
    if (var_name == L"history") {
        // We do this only on the main thread, matching env.cpp.
        if (is_main_thread()) {
            history = reader_get_history();
        }
    } else if (var_name != wcstring{VARIABLE_EXPAND_EMPTY}) {
        var = env_get(var_name);
    }

    // Parse out any following slice.
    // Record the end of the variable name and any following slice.
    size_t var_name_and_slice_stop = var_name_stop;
    bool all_values = true;
    const size_t slice_start = var_name_stop;
    // List of indexes, and parallel array of source positions of each index in the variable list.
    std::vector<long> var_idx_list;
    std::vector<size_t> var_pos_list;
    if (slice_start < insize && instr.at(slice_start) == L'[') {
        all_values = false;
        const wchar_t *in = instr.c_str();
        wchar_t *slice_end;
        // If a variable is missing, behave as though we have one value, so that $var[1] always
        // works.
        size_t effective_val_count = 1;
        if (var) {
            effective_val_count = var->as_list().size();
        } else if (history) {
//.........这里部分代码省略.........

/**
    Set the current bind mode
*/
void input_set_bind_mode(const wcstring &bm)
{
    env_set(FISH_BIND_MODE_VAR, bm.c_str(), ENV_GLOBAL);
}

//.........这里部分代码省略.........

    }
    else
    {
        /*
          Second or first mode. These suck, but we need to support
          them for backwards compatibility. At least for some
          time.

          Third mode was implemented in January 2007, and previous
          modes should be considered deprecated from that point
          forward. A reasonable time frame for removal of the code
          below has yet to be determined.
        */

        if (argc < 3)
        {
            print_help(argv[0], 1);
            exit(0);
        }
        else
        {
            mangle_descriptors = 1;

            prefix = str2wcstring(argv[2]);
            is_quoted = strcmp("1", argv[1])==0;

            if (argc > 3)
            {
                /*
                  First mode
                */
                for (i=3; i<argc; i++)
                {
                    wcstring wcs = str2wcstring(argv[i]);
                    comp.push_back(wcs);
                }
            }
            else
            {
                /*
                  Second mode
                */
                read_array(stdin, comp);
            }
        }

    }

//    debug( 3, L"prefix is '%ls'", prefix );

    init(mangle_descriptors, result_fd);

    mangle_descriptions(comp);

    if (prefix == L"-")
        join_completions(comp);

    std::vector<comp_t *> completions = mangle_completions(comp, prefix.c_str());

    /**
       Try to print the completions. Start by trying to print the
       list in PAGER_MAX_COLS columns, if the completions won't
       fit, reduce the number of columns by one. Printing a single
       column never fails.
    */
    for (i = PAGER_MAX_COLS; i>0; i--)
    {
        switch (completion_try_print(i, prefix.c_str(), is_quoted, completions))
        {

            case PAGER_RETRY:
                break;

            case PAGER_DONE:
                i=0;
                break;

            case PAGER_RESIZE:
                /*
                  This means we got a resize event, so we start
                  over from the beginning. Since it the screen got
                  bigger, we might be able to fit all completions
                  on-screen.
                */
                i=PAGER_MAX_COLS+1;
                break;

        }
    }

    fwprintf(out_file, L"%ls", out_buff.c_str());
    if (is_ca_mode)
    {
        writembs(exit_ca_mode);
        pager_flush();
    }
    destroy();

}

    bool replace_matches(const wchar_t *arg)
    {
        // A return value of true means all is well (even if no replacements
        // were performed), false indicates an unrecoverable error.
        if (regex.code == 0)
        {
            // pcre2_compile() failed
            return false;
        }

        uint32_t options = opts.all ? PCRE2_SUBSTITUTE_GLOBAL : 0;
        size_t arglen = wcslen(arg);
        PCRE2_SIZE bufsize = (arglen == 0) ? 16 : 2 * arglen;
        wchar_t *output = (wchar_t *)malloc(sizeof(wchar_t) * bufsize);
        if (output == 0)
        {
            DIE_MEM();
        }
        int pcre2_rc = 0;
        for (;;)
        {
            PCRE2_SIZE outlen = bufsize;
            pcre2_rc = pcre2_substitute(
                            regex.code,
                            PCRE2_SPTR(arg),
                            arglen,
                            0,  // start offset
                            options,
                            regex.match,
                            0,  // match context
                            PCRE2_SPTR(replacement.c_str()),
                            PCRE2_ZERO_TERMINATED,
                            (PCRE2_UCHAR *)output,
                            &outlen);

            if (pcre2_rc == PCRE2_ERROR_NOMEMORY)
            {
                if (bufsize < MAX_REPLACE_SIZE)
                {
                    bufsize = std::min(2 * bufsize, MAX_REPLACE_SIZE);
                    output = (wchar_t *)realloc(output, sizeof(wchar_t) * bufsize);
                    if (output == 0)
                    {
                        DIE_MEM();
                    }
                    continue;
                }
                string_error(streams, _(L"%ls: Replacement string too large\n"), argv0);
                free(output);
                return false;
            }
            break;
        }

        bool rc = true;
        if (pcre2_rc < 0)
        {
            string_error(streams, _(L"%ls: Regular expression substitute error: %ls\n"),
                    argv0, pcre2_strerror(pcre2_rc).c_str());
            rc = false;
        }
        else
        {
            if (!opts.quiet)
            {
                streams.out.append(output);
                streams.out.append(L'\n');
            }
            total_replaced += pcre2_rc;
        }

        free(output);
        return rc;
    }

/**
   This internal helper function does all the real work. By using two
   functions, the internal function can return on various places in
   the code, and the caller can take care of various cleanup work.

     cmd: the command name ('grep')
     really_load: whether to actually parse it as a function, or just check it it exists
     reload: whether to reload it if it's already loaded
     path_list: the set of paths to check

     Result: if really_load is true, returns whether the function was loaded. Otherwise returns whether the function existed.
*/
bool autoload_t::locate_file_and_maybe_load_it( const wcstring &cmd, bool really_load, bool reload, const wcstring_list_t &path_list )
{
    /* Note that we are NOT locked in this function! */
    size_t i;
    bool reloaded = 0;

    /* Try using a cached function. If we really want the function to be loaded, require that it be really loaded. If we're not reloading, allow stale functions. */
    {
        bool allow_stale_functions = ! reload;

        /* Take a lock */
        scoped_lock locker(lock);

        /* Get the function */
        autoload_function_t * func = this->get_node(cmd);

        /* Determine if we can use this cached function */
        bool use_cached;
        if (! func) {
            /* Can't use a function that doesn't exist */
            use_cached = false;
        } else if (really_load && ! func->is_placeholder && ! func->is_loaded) {
            /* Can't use an unloaded function */
            use_cached = false;
        } else if ( ! allow_stale_functions && is_stale(func)) {
            /* Can't use a stale function */
            use_cached = false;
        } else {
            /* I guess we can use it */
            use_cached = true;
        }

        /* If we can use this function, return whether we were able to access it */
        if (use_cached) {
            return func->is_internalized || func->access.accessible;
        }
    }
    /* The source of the script will end up here */
    wcstring script_source;
    bool has_script_source = false;

    /* Whether we found an accessible file */
    bool found_file = false;

    /* Look for built-in scripts via a binary search */
    const builtin_script_t *matching_builtin_script = NULL;
    if (builtin_script_count > 0)
    {
        const builtin_script_t test_script = {cmd.c_str(), NULL};
        const builtin_script_t *array_end = builtin_scripts + builtin_script_count;
        const builtin_script_t *found = std::lower_bound(builtin_scripts, array_end, test_script, script_name_precedes_script_name);
        if (found != array_end && ! wcscmp(found->name, test_script.name))
        {
            /* We found it */
            matching_builtin_script = found;
        }
    }
    if (matching_builtin_script) {
        has_script_source = true;
        script_source = str2wcstring(matching_builtin_script->def);

        /* Make a node representing this function */
        scoped_lock locker(lock);
        autoload_function_t *func = this->get_autoloaded_function_with_creation(cmd, really_load);

        /* This function is internalized */
        func->is_internalized = true;

        /* It's a fiction to say the script is loaded at this point, but we're definitely going to load it down below. */
        if (really_load) func->is_loaded = true;
    }

    if (! has_script_source)
    {
        /* Iterate over path searching for suitable completion files */
        for( i=0; i<path_list.size(); i++ )
        {
            wcstring next = path_list.at(i);
            wcstring path = next + L"/" + cmd + L".fish";

            const file_access_attempt_t access = access_file(path, R_OK);
            if (access.accessible) {
                /* Found it! */
                found_file = true;

                /* Now we're actually going to take the lock. */
                scoped_lock locker(lock);
                autoload_function_t *func = this->get_node(cmd);
//.........这里部分代码省略.........

/// Perform brace expansion.
static expand_error_t expand_braces(const wcstring &instr, expand_flags_t flags,
                                      std::vector<completion_t> *out, parse_error_list_t *errors) {
    bool syntax_error = false;
    int brace_count = 0;

    const wchar_t *brace_begin = NULL, *brace_end = NULL;
    const wchar_t *last_sep = NULL;

    const wchar_t *item_begin;
    size_t length_preceding_braces, length_following_braces, tot_len;

    const wchar_t *const in = instr.c_str();

    // Locate the first non-nested brace pair.
    for (const wchar_t *pos = in; (*pos) && !syntax_error; pos++) {
        switch (*pos) {
            case BRACE_BEGIN: {
                if (brace_count == 0) brace_begin = pos;
                brace_count++;
                break;
            }
            case BRACE_END: {
                brace_count--;
                if (brace_count < 0) {
                    syntax_error = true;
                } else if (brace_count == 0) {
                    brace_end = pos;
                }
                break;
            }
            case BRACE_SEP: {
                if (brace_count == 1) last_sep = pos;
                break;
            }
            default: {
                break;  // we ignore all other characters here
            }
        }
    }

    if (brace_count > 0) {
        if (!(flags & EXPAND_FOR_COMPLETIONS)) {
            syntax_error = true;
        } else {
            // The user hasn't typed an end brace yet; make one up and append it, then expand
            // that.
            wcstring mod;
            if (last_sep) {
                mod.append(in, brace_begin - in + 1);
                mod.append(last_sep + 1);
                mod.push_back(BRACE_END);
            } else {
                mod.append(in);
                mod.push_back(BRACE_END);
            }

            // Note: this code looks very fishy, apparently it has never worked.
            return expand_braces(mod, 1, out, errors);
        }
    }

    // Expand a literal "{}" to itself because it is useless otherwise,
    // and this eases e.g. `find -exec {}`. See #1109.
    if (brace_begin + 1 == brace_end) {
        wcstring newstr = instr;
        newstr.at(brace_begin - in) = L'{';
        newstr.at(brace_end - in) = L'}';
        return expand_braces(newstr, flags, out, errors);
    }

    if (syntax_error) {
        append_syntax_error(errors, SOURCE_LOCATION_UNKNOWN, _(L"Mismatched braces"));
        return EXPAND_ERROR;
    }

    if (brace_begin == NULL) {
        append_completion(out, instr);
        return EXPAND_OK;
    }

    length_preceding_braces = (brace_begin - in);
    length_following_braces = wcslen(brace_end) - 1;
    tot_len = length_preceding_braces + length_following_braces;
    item_begin = brace_begin + 1;
    for (const wchar_t *pos = (brace_begin + 1); true; pos++) {
        if (brace_count == 0 && ((*pos == BRACE_SEP) || (pos == brace_end))) {
            assert(pos >= item_begin);
            size_t item_len = pos - item_begin;
            wcstring item = wcstring(item_begin, item_len);
            item = trim(item, (const wchar_t[]) { BRACE_SPACE, L'\0' });
            for (auto &c : item) {
                if (c == BRACE_SPACE) {
                    c = ' ';
                }
            }

            wcstring whole_item;
            whole_item.reserve(tot_len + item_len + 2);
            whole_item.append(in, length_preceding_braces);
//.........这里部分代码省略.........

static bool path_get_path_core(const wcstring &cmd, wcstring *out_path, const env_var_t &bin_path_var)
{
    int err = ENOENT;

    debug(3, L"path_get_path( '%ls' )", cmd.c_str());

    /* If the command has a slash, it must be a full path */
    if (cmd.find(L'/') != wcstring::npos)
    {
        if (waccess(cmd, X_OK)==0)
        {
            struct stat buff;
            if (wstat(cmd, &buff))
            {
                return false;
            }

            if (S_ISREG(buff.st_mode))
            {
                if (out_path)
                    out_path->assign(cmd);
                return true;
            }
            else
            {
                errno = EACCES;
                return false;
            }
        }
        else
        {
            return false;
        }

    }
    else
    {
        wcstring bin_path;
        if (! bin_path_var.missing())
        {
            bin_path = bin_path_var;
        }
        else
        {
            if (contains(PREFIX L"/bin", L"/bin", L"/usr/bin"))
            {
                bin_path = L"/bin" ARRAY_SEP_STR L"/usr/bin";
            }
            else
            {
                bin_path = L"/bin" ARRAY_SEP_STR L"/usr/bin" ARRAY_SEP_STR PREFIX L"/bin";
            }
        }

        wcstring nxt_path;
        wcstokenizer tokenizer(bin_path, ARRAY_SEP_STR);
        while (tokenizer.next(nxt_path))
        {
            if (nxt_path.empty())
                continue;
            append_path_component(nxt_path, cmd);
            if (waccess(nxt_path, X_OK)==0)
            {
                struct stat buff;
                if (wstat(nxt_path, &buff)==-1)
                {
                    if (errno != EACCES)
                    {
                        wperror(L"stat");
                    }
                    continue;
                }
                if (S_ISREG(buff.st_mode))
                {
                    if (out_path)
                        out_path->swap(nxt_path);
                    return true;
                }
                err = EACCES;

            }
            else
            {
                switch (errno)
                {
                    case ENOENT:
                    case ENAMETOOLONG:
                    case EACCES:
                    case ENOTDIR:
                        break;
                    default:
                    {
                        debug(1,
                              MISSING_COMMAND_ERR_MSG,
                              nxt_path.c_str());
                        wperror(L"access");
                    }
                }
            }
        }
//.........这里部分代码省略.........