proctitle patch (useful) - Mailing list pgsql-general

when trying to diagnose problems, it is sometimes difficult to identify which
backend process is connected to what client process.

here is a patch for src/backend/commands/variable.c

this patch adds a new variable PROCTITLE.

this allows client processes to set the backend proctitle to something useful:

$ ps auxww | grep post
11080 ??  Is     0:00.06 postmaster -S -i -d 3 -o -F (postgres)
11125 ??  I      0:00.42 (postgres)

$ psql database
database=> SET PROCTITLE = 'testing proctitle 123';
SET VARIABLE
database=>

$ ps ax | grep post
11080 ??  Is     0:00.06 postmaster -S -i -d 3 -o -F (postgres)
11125 ??  I      0:00.21 postmaster: testing proctitle 123 (postgres)


i'm not overly familiar with GNU configure, so i'll leave it up to the people
who manage the source to figure out a clean portable way of enabling the
feature.

also note: not all systems have setproctitle(), although there is usually
a way to do it.

--
[ Jim Mercer                 jim@reptiles.org              +1 416 506-0654 ]
[          Reptilian Research -- Longer Life through Colder Blood          ]
[  Don't be fooled by cheap Finnish imitations; BSD is the One True Code.  ]

*** variable.c.orig    Fri Dec 24 11:23:42 1999
--- variable.c    Fri Dec 24 11:23:10 1999
***************
*** 21,26 ****
--- 21,32 ----
  #include "mb/pg_wchar.h"
  #endif

+ #define PROCTITLE
+ #ifdef PROCTITLE
+ static bool show_title(void);
+ static bool reset_title(void);
+ static bool parse_title(const char *);
+ #endif
  static bool show_date(void);
  static bool reset_date(void);
  static bool parse_date(const char *);
***************
*** 304,309 ****
--- 310,370 ----
      return TRUE;
  }

+ #ifdef PROCTITLE
+ /*
+  *
+  * PROCTITLE
+  *
+  */
+ static char *ProcTitle = NULL;
+ static bool
+ parse_title(const char *value)
+ {
+     if (value == NULL)
+     {
+         reset_title();
+         return TRUE;
+     }
+
+     if (ProcTitle != NULL)
+         free(ProcTitle);
+
+     ProcTitle = strdup(value);
+     setproctitle(ProcTitle);
+
+     return TRUE;
+ }
+
+ static bool
+ show_title()
+ {
+     char        buf[64];
+
+     strcpy(buf, "DateStyle is ");
+     if (ProcTitle != NULL)
+         strcat(buf, ProcTitle);
+     else
+         strcat(buf, "NULL");
+
+     elog(NOTICE, buf, NULL);
+
+     return TRUE;
+ }
+
+ static bool
+ reset_title()
+ {
+     if (ProcTitle != NULL)
+         {
+         free(ProcTitle);
+         ProcTitle = NULL;
+         }
+
+     setproctitle(ProcTitle);
+     return TRUE;
+ }
+ #endif
+
  /*
   *
   * DATE_STYLE
***************
*** 539,544 ****
--- 600,610 ----
  }            VariableParsers[] =

  {
+ #ifdef PROCTITLE
+     {
+         "proctitle", parse_title, show_title, reset_title
+     },
+ #endif
      {
          "datestyle", parse_date, show_date, reset_date
      },