/* Create transaction log symlink, if required */if (strcmp(xlog_dir, "") != 0){fprintf(stderr,"In main function -----------------190\n");char       *linkloc;/* clean up xlog directory name, check it's absolute */canonicalize_path(xlog_dir);if (!is_absolute_path(xlog_dir)){fprintf(stderr, _("%s: transaction log directory location must be an absolute path\n"), progname);exit_nicely();}/* check if the specified xlog directory exists/is empty */switch (pg_check_dir(xlog_dir)){case 0:/* xlog directory not there, must create it */printf(_("creating directory %s ... "),xlog_dir);fflush(stdout);if (pg_mkdir_p(xlog_dir, S_IRWXU) != 0){fprintf(stderr, _("%s: could not create directory \"%s\": %s\n"),progname, xlog_dir, strerror(errno));exit_nicely();}elsecheck_ok();made_new_xlogdir = true;break;case 1:/* Present but empty, fix permissions and use it */printf(_("fixing permissions on existing directory %s ... "),xlog_dir);fflush(stdout);if (chmod(xlog_dir, S_IRWXU) != 0){fprintf(stderr, _("%s: could not change permissions of directory \"%s\": %s\n"),progname, xlog_dir, strerror(errno));exit_nicely();}elsecheck_ok();found_existing_xlogdir = true;break;case 2:/* Present and not empty */fprintf(stderr,_("%s: directory \"%s\" exists but is not empty\n"),progname, xlog_dir);fprintf(stderr,_("If you want to store the transaction log there, either\n""remove or empty the directory \"%s\".\n"),xlog_dir);exit_nicely();default:/* Trouble accessing directory */fprintf(stderr, _("%s: could not access directory \"%s\": %s\n"),progname, xlog_dir, strerror(errno));exit_nicely();}/* form name of the place where the symlink must go */linkloc = (char *) pg_malloc(strlen(pg_data) + 8 + 1);sprintf(linkloc, "%s/pg_xlog", pg_data);#ifdef HAVE_SYMLINKif (symlink(xlog_dir, linkloc) != 0){fprintf(stderr, _("%s: could not create symbolic link \"%s\": %s\n"),progname, linkloc, strerror(errno));exit_nicely();}
#elsefprintf(stderr, _("%s: symlinks are not supported on this platform"));exit_nicely();
#endif}

    /* Create required subdirectories */printf(_("creating subdirectories ... "));fflush(stdout);for (i = 0; i < (sizeof(subdirs) / sizeof(char *)); i++){if (!mkdatadir(subdirs[i]))exit_nicely();}

subdirs[0] is: global

subdirs[1] is: pg_xlog

subdirs[2] is: pg_xlog/archive_status

subdirs[3] is: pg_clog

subdirs[4] is: pg_notify

subdirs[5] is: pg_serial

subdirs[6] is: pg_subtrans

subdirs[7] is: pg_twophase

subdirs[8] is: pg_multixact/members

subdirs[9] is: pg_multixact/offsets

subdirs[10] is: base

subdirs[11] is: base/1

subdirs[12] is: pg_tblspc

subdirs[13] is: pg_stat_tmp

    static const char *subdirs[] = {"global","pg_xlog","pg_xlog/archive_status","pg_clog","pg_notify","pg_serial","pg_subtrans","pg_twophase","pg_multixact/members","pg_multixact/offsets","base","base/1","pg_tblspc","pg_stat_tmp"};

    check_ok();

/** call exit_nicely() if we got a signal, or else output "ok".*/
static void
check_ok(void)
{if (caught_signal){printf(_("caught signal\n"));fflush(stdout);exit_nicely();}else if (output_failed){printf(_("could not write to child process: %s\n"),strerror(output_errno));fflush(stdout);exit_nicely();}else{/* all seems well */printf(_("ok\n"));fflush(stdout);}
}