分享程序员开发的那些事...
更新时间：2022-09-22 23:02:18
继续分析
下面的是获取运行此程序的用户名称，主要还是为了防止在linux下用root来运行的情形。
effective_user = get_id(); if (strlen(username) == 0) username = effective_user;
接下来，是准备好一写预备生成的文件的名称变量：
set_input(&bki_file, "postgres.bki"); set_input(&desc_file, "postgres.description"); set_input(&shdesc_file, "postgres.shdescription"); set_input(&hba_file, "pg_hba.conf.sample"); set_input(&ident_file, "pg_ident.conf.sample"); set_input(&conf_file, "postgresql.conf.sample"); set_input(&conversion_file, "conversion_create.sql"); set_input(&dictionary_file, "snowball_create.sql"); set_input(&info_schema_file, "information_schema.sql"); set_input(&features_file, "sql_features.txt"); set_input(&system_views_file, "system_views.sql");
接下来，这个函数很有趣，是为了information_schema的版本信息的：
set_info_version();
展开后可以看到：
调试其代码，可以得到 infoversion 的信息是：09.01.0002
/* * extract the strange version of version required for information schema * (09.08.0007abc) */ static void set_info_version(void) { char *letterversion; long major = 0, minor = 0, micro = 0; char *endptr; char *vstr = xstrdup(PG_VERSION); char *ptr; ptr = vstr + (strlen(vstr) - 1); while (ptr != vstr && (*ptr < '0' || *ptr > '9')) ptr--; letterversion = ptr + 1; major = strtol(vstr, &endptr, 10); if (*endptr) minor = strtol(endptr + 1, &endptr, 10); if (*endptr) micro = strtol(endptr + 1, &endptr, 10); snprintf(infoversion, sizeof(infoversion), "%02ld.%02ld.%04ld%s", major, minor, micro, letterversion); }
接下来，看这个，因为没设置debug状态之类的，所以可以跳过：
if (show_setting || debug) { fprintf(stderr, "VERSION=%s\n" "PGDATA=%s\nshare_path=%s\nPGPATH=%s\n" "POSTGRES_SUPERUSERNAME=%s\nPOSTGRES_BKI=%s\n" "POSTGRES_DESCR=%s\nPOSTGRES_SHDESCR=%s\n" "POSTGRESQL_CONF_SAMPLE=%s\n" "PG_HBA_SAMPLE=%s\nPG_IDENT_SAMPLE=%s\n", PG_VERSION, pg_data, share_path, bin_path, username, bki_file, desc_file, shdesc_file, conf_file, hba_file, ident_file); if (show_setting) exit(0); }
再往下看：
check_input(bki_file);
check_input(desc_file);
check_input(shdesc_file);
check_input(hba_file);
check_input(ident_file);
check_input(conf_file);
check_input(conversion_file);
check_input(dictionary_file);
check_input(info_schema_file);
check_input(features_file);
check_input(system_views_file);
check_input，在这里是检查文件是否存在。
其实，postgres.bki等文件，都位于 src/backend/catalog目录下......
接下来：
setlocales();
展开后看：发现得到的 locale 变量是个空值。
/* * set up the locale variables * * assumes we have called setlocale(LC_ALL,"") */ static void setlocales(void) { /* set empty lc_* values to locale config if set */ if (strlen(locale) > 0) { if (strlen(lc_ctype) == 0) lc_ctype = locale; if (strlen(lc_collate) == 0) lc_collate = locale; if (strlen(lc_numeric) == 0) lc_numeric = locale; if (strlen(lc_time) == 0) lc_time = locale; if (strlen(lc_monetary) == 0) lc_monetary = locale; if (strlen(lc_messages) == 0) lc_messages = locale; } /* * override absent/invalid config settings from initdb's locale settings */ if (strlen(lc_ctype) == 0 || !check_locale_name(lc_ctype)) lc_ctype = xstrdup(setlocale(LC_CTYPE, NULL)); if (strlen(lc_collate) == 0 || !check_locale_name(lc_collate)) lc_collate = xstrdup(setlocale(LC_COLLATE, NULL)); if (strlen(lc_numeric) == 0 || !check_locale_name(lc_numeric)) lc_numeric = xstrdup(setlocale(LC_NUMERIC, NULL)); if (strlen(lc_time) == 0 || !check_locale_name(lc_time)) lc_time = xstrdup(setlocale(LC_TIME, NULL)); if (strlen(lc_monetary) == 0 || !check_locale_name(lc_monetary)) lc_monetary = xstrdup(setlocale(LC_MONETARY, NULL)); if (strlen(lc_messages) == 0 || !check_locale_name(lc_messages)) #if defined(LC_MESSAGES) && !defined(WIN32) { /* when available get the current locale setting */ lc_messages = xstrdup(setlocale(LC_MESSAGES, NULL)); } #else { /* when not available, get the CTYPE setting */ lc_messages = xstrdup(setlocale(LC_CTYPE, NULL)); } #endif}