继续分析

下面这一段,当 initdb --version 或者  initdb --help 才有意义。

    if (argc > 1)
    {

        if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
        {
            usage(progname);
            exit(0);
        }
        if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
        {
            puts("initdb (PostgreSQL) " PG_VERSION);
            exit(0);
        }
    }

再看下一段:

实际上就是 initdb 运行时候,后面可以跟各种参数。我这里只考虑 -D那种就好了

    /* process command-line options */
    while ((c = getopt_long(argc, argv, "dD:E:L:nU:WA:sT:X:", long_options, &option_index)) != -1)
    {
        switch (c)
        {
            case 'A':
                authmethod = xstrdup(optarg);
                break;
            case 'D':
                pg_data = xstrdup(optarg);
                break;
            case 'E':
                encoding = xstrdup(optarg);
                break;
            case 'W':
                pwprompt = true;
                break;
            case 'U':
                username = xstrdup(optarg);
                break;
            case 'd':
                debug = true;
                printf(_("Running in debug mode.\n"));
                break;
            case 'n':
                noclean = true;
                printf(_("Running in noclean mode.  Mistakes will not be cleaned up.\n"));
                break;
            case 'L':
                share_path = xstrdup(optarg);
                break;
            case 1:
                locale = xstrdup(optarg);
                break;
            case 2:
                lc_collate = xstrdup(optarg);
                break;
            case 3:
                lc_ctype = xstrdup(optarg);
                break;
            case 4:
                lc_monetary = xstrdup(optarg);
                break;
            case 5:
                lc_numeric = xstrdup(optarg);
                break;
            case 6:
                lc_time = xstrdup(optarg);
                break;
            case 7:
                lc_messages = xstrdup(optarg);
                break;
            case 8:
                locale = "C";
                break;
            case 9:
                pwfilename = xstrdup(optarg);
                break;
            case 's':
                show_setting = true;
                break;
            case 'T':
                default_text_search_config = xstrdup(optarg);
                break;
            case 'X':
                xlog_dir = xstrdup(optarg);
                break;
            default:
                /* getopt_long already emitted a complaint */
                fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
                        progname);
                exit(1);
        }
    }

也就是这段:

            case 'D':
                pg_data = xstrdup(optarg);
                break;