In pg_upgrade, add various logging improvements:

add ability to control permissions of created files
	have psql echo its queries for easier debugging
	output four separate log files, and delete them on success
	add -r/--retain option to keep log files after success
	make logs file append-only
	remove -g/-G/-l logging options
	sugggest tailing appropriate log file on failure
	enhance -v/--verbose behavior

contrib/pg_upgrade/pg_upgrade.h

@@ -35,6 +35,34 @@
 #define GLOBALS_DUMP_FILE	"pg_upgrade_dump_globals.sql"
 #define DB_DUMP_FILE		"pg_upgrade_dump_db.sql"
 
+#define SERVER_LOG_FILE		"pg_upgrade_server.log"
+#define RESTORE_LOG_FILE	"pg_upgrade_restore.log"
+#define UTILITY_LOG_FILE	"pg_upgrade_utility.log"
+#define INTERNAL_LOG_FILE	"pg_upgrade_internal.log"
+
+#define NUM_LOG_FILES		4
+extern char *output_files[];
+
+/*
+ * WIN32 files do not accept writes from multiple processes
+ *
+ * On Win32, we can't send both pg_upgrade output and command output to the
+ * same file because we get the error: "The process cannot access the file
+ * because it is being used by another process." so send the pg_ctl
+ * command-line output to the utility log file on Windows, rather than
+ * into the server log file.
+ *
+ * We could use the Windows pgwin32_open() flags to allow shared file
+ * writes but is unclear how all other tools would use those flags, so
+ * we just avoid it and log a little differently on Windows;  we adjust
+ * the error message appropriately.
+ */
+#ifndef WIN32
+#define SERVER_LOG_FILE2	SERVER_LOG_FILE
+#else
+#define SERVER_LOG_FILE2	UTILITY_LOG_FILE
+#endif
+
 #ifndef WIN32
 #define pg_copy_file		copy_file
 #define pg_mv_file			rename
@@ -166,11 +194,10 @@ typedef enum
  */
 typedef enum
 {
-	PG_INFO,
+	PG_VERBOSE,
 	PG_REPORT,
 	PG_WARNING,
-	PG_FATAL,
-	PG_DEBUG
+	PG_FATAL
 } eLogType;
 
 
@@ -204,25 +231,9 @@ typedef struct
 */
 typedef struct
 {
-	char	   *filename;		/* name of log file (may be /dev/null) */
-	/*
-	 * WIN32 files do not accept writes from multiple processes
-	 *
-	 * On Win32, we can't send both pg_upgrade output and command output to the
-	 * same file because we get the error: "The process cannot access the file
-	 * because it is being used by another process." so we have to send all
-	 * other output to 'nul'.  Therefore, we set this to DEVNULL on Win32, and
-	 * it equals 'filename' on all other platforms.
-	 *
-	 * We could use the Windows pgwin32_open() flags to allow shared file
-	 * writes but is unclear how all other tools would use those flags, so
-	 * we just avoid it and log a little less on Windows.
-	 */
-	char	   *filename2;
-	FILE	   *fd;				/* log FILE */
-	bool		debug;			/* TRUE -> log more information */
-	FILE	   *debug_fd;		/* debug-level log FILE */
+	FILE	   *internal;		/* internal log FILE */
 	bool		verbose;		/* TRUE -> be verbose in messages */
+	bool		retain;			/* retain log files on success */
 } LogOpts;
 
 
@@ -245,7 +256,6 @@ typedef struct
 	const char *progname;		/* complete pathname for this program */
 	char	   *exec_path;		/* full path to my executable */
 	char	   *user;			/* username for clusters */
-	char		cwd[MAXPGPATH]; /* current working directory, used for output */
 	char	  **tablespaces;	/* tablespaces */
 	int			num_tablespaces;
 	char	  **libraries;		/* loadable libraries */
@@ -294,8 +304,9 @@ void		split_old_dump(void);
 
 /* exec.c */
 
-int exec_prog(bool throw_error, const char *cmd, ...)
-	__attribute__((format(PG_PRINTF_ATTRIBUTE, 2, 3)));
+int exec_prog(bool throw_error, bool is_priv,
+	const char *log_file, const char *cmd, ...)
+	__attribute__((format(PG_PRINTF_ATTRIBUTE, 4, 5)));
 void		verify_directories(void);
 bool		is_server_running(const char *datadir);
 
@@ -339,6 +350,7 @@ const char *linkAndUpdateFile(pageCnvCtx *pageConverter, const char *src,
 				  const char *dst);
 
 void		check_hard_link(void);
+FILE 	   *fopen_priv(const char *path, const char *mode);
 
 /* function.c */