I'm in TODO mood today ...

* Document/trigger/rule so changes to pg_shadow recreate pg_pwd

I did it with a trigger and it seems to work like a charm. The function
that already updates the file for create and alter user has been made a
built-in "SQL" function and a trigger is created at initdb time.

Comments around the pg_pwd updating function seem to be worried about
this
routine being called concurrently, but I really don't see a reason to
worry about this. Verify for yourself. I guess we never had a system
trigger before, so treat this with care, and feel free to adjust the
nomenclature as well.

--
Peter Eisentraut                  Sernanders väg 10:115

Author: bmomjian

doc/TODO

@@ -204,7 +204,7 @@ MISC
 * Do autocommit so always in a transaction block(?)
 * Show location of syntax error in query [yacc]
 * Redesign the function call interface to handle NULLs better [function]
-* Document/trigger/rule so changes to pg_shadow recreate pg_pwd [pg_shadow]
+* -Document/trigger/rule so changes to pg_shadow recreate pg_pwd [pg_shadow]
 * Missing optimizer selectivities for date, r-tree, etc. [optimizer]
 * -Overhaul mdmgr/smgr to fix double unlinking and double opens, cleanup
 * Overhaul bufmgr/lockmgr/transaction manager

src/backend/commands/user.c

@@ -5,7 +5,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: user.c,v 1.40 1999/11/30 04:29:56 momjian Exp $
+ * $Id: user.c,v 1.41 1999/12/12 05:57:28 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,8 +43,13 @@ static void CheckPgUserAclNotNull(void);
  * pg_shadow is the standard way to do that.
  *---------------------------------------------------------------------
  */
-static void
-UpdatePgPwdFile(void)
+
+/* This is the old name. Now uses a lower case name to be able to call this
+   from SQL. */
+#define UpdatePgPwdFile() update_pg_pwd()
+
+void
+update_pg_pwd()
 {
 	char	   *filename,
 			   *tempname;
@@ -71,7 +76,7 @@ UpdatePgPwdFile(void)
 		   false,				/* from */
 		   false,				/* pipe */
 		   tempname,			/* filename */
-		   CRYPT_PWD_FILE_SEPCHAR, /* delim */
+		   CRYPT_PWD_FILE_SEPSTR, /* delim */
 		   0077);				/* fileumask */
 	/*
 	 * And rename the temp file to its final name, deleting the old pg_pwd.

src/bin/initdb/initdb.sh

@@ -26,7 +26,7 @@
 #
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.63 1999/12/09 04:36:57 momjian Exp $
+#    $Header: /cvsroot/pgsql/src/bin/initdb/Attic/initdb.sh,v 1.64 1999/12/12 05:57:30 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -412,6 +412,10 @@ echo
 
 PGSQL_OPT="-o /dev/null -O -F -Q -D$PGDATA"
 
+# Create a trigger so that direct updates to pg_shadow will be written
+# to the flat password file pg_pwd
+echo "CREATE TRIGGER pg_sync_pg_pwd AFTER INSERT OR UPDATE OR DELETE ON pg_shadow FOR EACH ROW EXECUTE PROCEDURE update_pg_pwd()" | postgres $PGSQL_OPT template1 > /dev/null
+
 # Create the initial pg_pwd (flat-file copy of pg_shadow)
 echo "COPY pg_shadow TO '$PGDATA/pg_pwd' USING DELIMITERS '\\t'" | \
 	postgres $PGSQL_OPT template1 > /dev/null

src/include/catalog/pg_proc.h

@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: pg_proc.h,v 1.108 1999/12/01 18:03:26 momjian Exp $
+ * $Id: pg_proc.h,v 1.109 1999/12/12 05:57:36 momjian Exp $
  *
  * NOTES
  *	  The script catalog/genbki.sh reads this file and generates .bki
@@ -93,6 +93,8 @@ typedef FormData_pg_proc *Form_pg_proc;
 /* keep the following ordered by OID so that later changes can be made easier */
 
 /* OIDS 1 - 99 */
+DATA(insert OID = 12  (  update_pg_pwd     PGUID 11 f t f 0 f 0  ""  100 0 0 100  update_pg_pwd - ));
+DESCR("update pg_pwd file");
 
 DATA(insert OID = 1242 (  boolin		   PGUID 11 f t t 1 f 16 "0" 100 0 0  100  boolin - ));
 DESCR("(internal)");