PostgreSQL的initdb 源代码分析之五

接前面，继续分析： putenv("TZ=GMT") 设置了时区信息。

find_other_exec(argv[0], "postgres", PG_BACKEND_VERSIONSTR, backend_exec))

就是要找到同目录下、同版本的postgres备用。initdb 执行后期，很多事情要依赖 postgres来处理的。

/*
* Also ensure that TZ is set, so that we don't waste time identifying the
* system timezone each of the many times we start a standalone backend.
* It's okay to use a hard-wired value here because nothing done during
* initdb cares about the timezone setting.
*/
putenv("TZ=GMT");

if ((ret = find_other_exec(argv[0], "postgres", PG_BACKEND_VERSIONSTR,
backend_exec)) < 0)
{
char        full_path[MAXPGPATH];

if (find_my_exec(argv[0], full_path) < 0)
strlcpy(full_path, progname, sizeof(full_path));

if (ret == -1)
fprintf(stderr,
_("The program \"postgres\" is needed by %s "
"but was not found in the\n"
"same directory as \"%s\".\n"
"Check your installation.\n"),
progname, full_path);
else
fprintf(stderr,
_("The program \"postgres\" was found by \"%s\"\n"
"but was not the same version as %s.\n"
"Check your installation.\n"),
full_path, progname);
exit(1);
}

接下来，获得路径：

一个是 bin_path： 就是initdb执行的路径。我运行的结果是： /home/pgsql/project/bin

一个是 share_path： 就是一些共享用信息的路径。我运行的结果是： /home/pgsql/project/share

/* store binary directory */
strcpy(bin_path, backend_exec);
*last_dir_separator(bin_path) = '\0';
canonicalize_path(bin_path);

fprintf(stderr,"bin_path is: %s \n",bin_path);

if (!share_path)
{
share_path = pg_malloc(MAXPGPATH);
get_share_path(backend_exec, share_path);
}
else if (!is_absolute_path(share_path))
{
fprintf(stderr, _("%s: input file location must be an absolute path\n"), progname);
exit(1);
}

canonicalize_path(share_path);

fprintf(stderr,"share_path is: %s \n",share_path);