Make pg_ctl status do a kill() test to verify that the PID found in

postmaster.pid still represents a live postmaster.

diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index a73ddffd323d3f6f56ea32c3cd4a97910cc7abd6..3fc0883678333d6ecbdecf6b2757d3b583fa8f17 100644 (file)
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -4,7 +4,7 @@
  *
  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.55 2005/03/11 17:20:33 momjian Exp $
+ * $PostgreSQL: pgsql/src/bin/pg_ctl/pg_ctl.c,v 1.56 2005/04/20 23:10:16 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -236,7 +236,7 @@ static pgpid_t
 get_pgpid(void)
 {
    FILE       *pidf;
-   pgpid_t     pid;
+   long        pid;
 
    pidf = fopen(pid_file, "r");
    if (pidf == NULL)
@@ -246,14 +246,19 @@ get_pgpid(void)
            return 0;
        else
        {
-           write_stderr(_("%s: could not open PID file \"%s\": %s"),
+           write_stderr(_("%s: could not open PID file \"%s\": %s\n"),
                         progname, pid_file, strerror(errno));
            exit(1);
        }
    }
-   fscanf(pidf, "%ld", &pid);
+   if (fscanf(pidf, "%ld", &pid) != 1)
+   {
+       write_stderr(_("%s: invalid data in PID file \"%s\"\n"),
+                    progname, pid_file);
+       exit(1);
+   }
    fclose(pidf);
-   return pid;
+   return (pgpid_t) pid;
 }
 
 
@@ -766,34 +771,67 @@ do_reload(void)
  * utility routines
  */
 
+static bool
+postmaster_is_alive(pid_t pid)
+{
+   /*
+    * Test to see if the process is still there.  Note that we do not
+    * consider an EPERM failure to mean that the process is still there;
+    * EPERM must mean that the given PID belongs to some other userid,
+    * and considering the permissions on $PGDATA, that means it's not
+    * the postmaster we are after.
+    *
+    * Don't believe that our own PID or parent shell's PID is the postmaster,
+    * either.  (Windows hasn't got getppid(), though.)
+    */
+   if (pid == getpid())
+       return false;
+#ifndef WIN32
+   if (pid == getppid())
+       return false;
+#endif
+   if (kill(pid, 0) == 0)
+       return true;
+   return false;
+}
+
 static void
 do_status(void)
 {
    pgpid_t     pid;
 
    pid = get_pgpid();
-   if (pid == 0)               /* no pid file */
-   {
-       printf(_("%s: neither postmaster nor postgres running\n"), progname);
-       exit(1);
-   }
-   else if (pid < 0)           /* standalone backend */
-   {
-       pid = -pid;
-       printf(_("%s: a standalone backend \"postgres\" is running (PID: %ld)\n"), progname, pid);
-   }
-   else
-   /* postmaster */
+   if (pid != 0)               /* 0 means no pid file */
    {
-       char      **optlines;
+       if (pid < 0)            /* standalone backend */
+       {
+           pid = -pid;
+           if (postmaster_is_alive((pid_t) pid))
+           {
+               printf(_("%s: a standalone backend \"postgres\" is running (PID: %ld)\n"),
+                      progname, pid);
+               return;
+           }
+       }
+       else                    /* postmaster */
+       {
+           if (postmaster_is_alive((pid_t) pid))
+           {
+               char      **optlines;
 
-       printf(_("%s: postmaster is running (PID: %ld)\n"), progname, pid);
+               printf(_("%s: postmaster is running (PID: %ld)\n"),
+                      progname, pid);
 
-       optlines = readfile(postopts_file);
-       if (optlines != NULL)
-           for (; *optlines != NULL; optlines++)
-               fputs(*optlines, stdout);
+               optlines = readfile(postopts_file);
+               if (optlines != NULL)
+                   for (; *optlines != NULL; optlines++)
+                       fputs(*optlines, stdout);
+               return;
+           }
+       }
    }
+   printf(_("%s: neither postmaster nor postgres running\n"), progname);
+   exit(1);
 }