设置环境变量（pg_data等），获取系统配置文件的源文件路径（postgres.bki、postgresql.conf. sample等文件），并检查该路径下各文件的可用性。
一、设置环境变量
set_pglocale_pgservice函数设置应用指定的locale和service目录。对于第一个if判断，如果在后端postgres中，则不需要设置LC_ALL，目前在initdb中则执行setlocale(LC_ALL, "")。如果定义了ENABLE_NLS,则需要调用get_locale_path，如果getenv("PGLOCALEDIR")为NULL，需要将PGLOCALEDIR和路径放入extern char **environ所指向的内存，用于后续设置环境变量。如果getenv("PGSYSCONFDIR")为NULL，需要将PGSYSCONFDIR和路径放入extern char **environ所指向的内存，用于后续设置环境变量。
1 void set_pglocale_pgservice(const char *argv0, const char *app){
2 char path[MAXPGPATH];
3 char my_exec_path[MAXPGPATH];
4 char env_path[MAXPGPATH + sizeof("PGSYSCONFDIR=")]; /* longer than PGLOCALEDIR */
5 /* don't set LC_ALL in the backend */
6 if (strcmp(app, PG_TEXTDOMAIN("postgres")) != 0)
7 setlocale(LC_ALL, "");
8 if (find_my_exec(argv0, my_exec_path) < 0)
9 return;
10 #ifdef ENABLE_NLS
11 get_locale_path(my_exec_path, path);
12 bindtextdomain(app, path);
13 textdomain(app);
14 if (getenv("PGLOCALEDIR") == NULL){
15 /* set for libpq to use */
16 snprintf(env_path, sizeof(env_path), "PGLOCALEDIR=%s", path);
17 canonicalize_path(env_path + 12);
18 putenv(strdup(env_path));
19 }
20 #endif
21 if (getenv("PGSYSCONFDIR") == NULL){
22 get_etc_path(my_exec_path, path);
23 /* set for libpq to use */
24 snprintf(env_path, sizeof(env_path), "PGSYSCONFDIR=%s", path);
25 canonicalize_path(env_path + 13);
26 putenv(strdup(env_path));
27 }
28 }
如果pg_data为空的话，则需要设置pg_data，后续的程序就是用于处理这样的情况，从环境变量取出PGDATA。这里属于参数处理部分，因为可以不指定数据目录，通过指定环境变量PGDATA来指定数据目录。
1 if (strlen(pg_data) == 0){
2 pgdenv = getenv("PGDATA");
3 if (pgdenv && strlen(pgdenv)){
4 /* PGDATA found */
5 pg_data = xstrdup(pgdenv);
6 }else{
7 fprintf(stderr,
8 _("%s: no data directory specified\n"
9 "You must identify the directory where the data for this database system\n"
10 "will reside. Do this with either the invocation option -D or the\n"
11 "environment variable PGDATA.\n"),
12 progname);
13 exit(1);
14 }
15 }
通过设置PGDATA环境变量来传送数据目录给其他程序，而不通过命令行以避免windows的dumb quoting文件
1 /* we have to set PGDATA for postgres rather than pass it on the command 2 * line to avoid dumb quoting problems on Windows, and we would especially 3 * need quotes otherwise on Windows because paths there are most likely to 4 * have embedded spaces. */ 5 pgdenv = pg_malloc(8 + strlen(pg_data)); 6 sprintf(pgdenv, "PGDATA=%s", pg_data); 7 putenv(pgdenv);
二、获取系统配置文件的源文件路径
提取bin的路径存储到bin_path中，提取share的路径存储到share_path中（下面代码中没有列出），获取执行程序的用户id
1 if ((ret = find_other_exec(argv[0], "postgres", PG_BACKEND_VERSIONSTR, backend_exec)) < 0){
2 char full_path[MAXPGPATH];
3 if (find_my_exec(argv[0], full_path) < 0)
4 strlcpy(full_path, progname, sizeof(full_path));
5 if (ret == -1)
6 fprintf(stderr,
7 _("The program \"postgres\" is needed by %s "
8 "but was not found in the\n"
9 "same directory as \"%s\".\n"
10 "Check your installation.\n"),
11 progname, full_path);
12 else
13 fprintf(stderr,
14 _("The program \"postgres\" was found by \"%s\"\n"
15 "but was not the same version as %s.\n"
16 "Check your installation.\n"),
17 full_path, progname);
18 exit(1);
19 }
/* store binary directory */
strcpy(bin_path, backend_exec);
*last_dir_separator(bin_path) = '\0';
canonicalize_path(bin_path);
...
effective_user = get_id();
if (strlen(username) == 0)
username = effective_user;
设置初始化过程中的需要使用的一些文件，将这些文件的文件名设置到程序变量中。
1 set_input(&bki_file, "postgres.bki"); 2 set_input(&desc_file, "postgres.description"); 3 set_input(&shdesc_file, "postgres.shdescription"); 4 set_input(&hba_file, "pg_hba.conf.sample"); 5 set_input(&ident_file, "pg_ident.conf.sample"); 6 set_input(&conf_file, "postgresql.conf.sample"); 7 set_input(&conversion_file, "conversion_create.sql"); 8 set_input(&dictionary_file, "snowball_create.sql"); 9 set_input(&info_schema_file, "information_schema.sql"); 10 set_input(&features_file, "sql_features.txt"); 11 set_input(&system_views_file, "system_views.sql"); 12 ... 13 check_input(bki_file); 14 check_input(desc_file); 15 check_input(shdesc_file); 16 check_input(hba_file); 17 check_input(ident_file); 18 check_input(conf_file); 19 check_input(conversion_file); 20 check_input(dictionary_file); 21 check_input(info_schema_file); 22 check_input(features_file); 23 check_input(system_views_file);
三、设置本地化locale
先需要执行setlocale(LC_ALL,"")，调用setlocales()函数
1 static void setlocales(void){
2 /* set empty lc_* values to locale config if set */
3 if (strlen(locale) > 0) {
4 if (strlen(lc_ctype) == 0)
5 lc_ctype = locale;
6 if (strlen(lc_collate) == 0)
7 lc_collate = locale;
8 if (strlen(lc_numeric) == 0)
9 lc_numeric = locale;
10 if (strlen(lc_time) == 0)
11 lc_time = locale;
12 if (strlen(lc_monetary) == 0)
13 lc_monetary = locale;
14 if (strlen(lc_messages) == 0)
15 lc_messages = locale;
16 }
17 /* override absent/invalid config settings from initdb's locale settings */
18 if (strlen(lc_ctype) == 0 || !check_locale_name(lc_ctype))
19 lc_ctype = xstrdup(setlocale(LC_CTYPE, NULL));
20 if (strlen(lc_collate) == 0 || !check_locale_name(lc_collate))
21 lc_collate = xstrdup(setlocale(LC_COLLATE, NULL));
22 if (strlen(lc_numeric) == 0 || !check_locale_name(lc_numeric))
23 lc_numeric = xstrdup(setlocale(LC_NUMERIC, NULL));
24 if (strlen(lc_time) == 0 || !check_locale_name(lc_time))
25 lc_time = xstrdup(setlocale(LC_TIME, NULL));
26 if (strlen(lc_monetary) == 0 || !check_locale_name(lc_monetary))
27 lc_monetary = xstrdup(setlocale(LC_MONETARY, NULL));
28 if (strlen(lc_messages) == 0 || !check_locale_name(lc_messages))
29 #if defined(LC_MESSAGES) && !defined(WIN32)
30 {
31 /* when available get the current locale setting */
32 lc_messages = xstrdup(setlocale(LC_MESSAGES, NULL));
33 }
34 #else
35 {
36 /* when not available, get the CTYPE setting */
37 lc_messages = xstrdup(setlocale(LC_CTYPE, NULL));
38 }
39 #endif
40 }
检查encoding设置，如果没有设置，就进行设置
1 if (strlen(encoding) == 0){
2 int ctype_enc;
3 ctype_enc = pg_get_encoding_from_locale(lc_ctype);
4 if (ctype_enc == PG_SQL_ASCII &&
5 !(pg_strcasecmp(lc_ctype, "C") == 0 ||
6 pg_strcasecmp(lc_ctype, "POSIX") == 0)){
7 /* Hmm, couldn't recognize the locale's codeset */
8 fprintf(stderr, _("%s: could not find suitable encoding for locale %s\n"),
9 progname, lc_ctype);
10 fprintf(stderr, _("Rerun %s with the -E option.\n"), progname);
11 fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
12 progname);
13 exit(1);
14 }
15 else if (!pg_valid_server_encoding_id(ctype_enc)){
16 /* We recognized it, but it's not a legal server encoding */
17 fprintf(stderr,
18 _("%s: locale %s requires unsupported encoding %s\n"),
19 progname, lc_ctype, pg_encoding_to_char(ctype_enc));
20 fprintf(stderr,
21 _("Encoding %s is not allowed as a server-side encoding.\n"
22 "Rerun %s with a different locale selection.\n"),
23 pg_encoding_to_char(ctype_enc), progname);
24 exit(1);
25 }else{
26 encodingid = encodingid_to_string(ctype_enc);
27 printf(_("The default database encoding has accordingly been set to %s.\n"),
28 pg_encoding_to_char(ctype_enc));
29 }
30 }
31 else
32 encodingid = get_encoding_id(encoding);
33 user_enc = atoi(encodingid);
34 if (!check_locale_encoding(lc_ctype, user_enc) ||
35 !check_locale_encoding(lc_collate, user_enc))
36 exit(1); /* check_locale_encoding printed the error */
37 if (strlen(default_text_search_config) == 0)
38 {
39 default_text_search_config = find_matching_ts_config(lc_ctype);
40 if (default_text_search_config == NULL)
41 {
42 printf(_("%s: could not find suitable text search configuration for locale %s\n"),
43 progname, lc_ctype);
44 default_text_search_config = "simple";
45 }
46 }
47 else
48 {
49 const char *checkmatch = find_matching_ts_config(lc_ctype);
50
51 if (checkmatch == NULL)
52 {
53 printf(_("%s: warning: suitable text search configuration for locale %s is unknown\n"),
54 progname, lc_ctype);
55 }
56 else if (strcmp(checkmatch, default_text_search_config) != 0)
57 {
58 printf(_("%s: warning: specified text search configuration \"%s\" might not match locale %s\n"),
59 progname, default_text_search_config, lc_ctype);
60 }
61 }