start of an admin tool for FreeBSD to help configure shared memory for

that machine

I kept the name as generic as possible though, as other OS should have
similar methods, so this can be extended "as appropriate" ...

contrib/ipc_check/README

+
+This simple perl script was designed under FreeBSD, and, right now, is
+limited to it.  It provides a simple way of determining and directing
+administrators in what has to be done to get IPC working, and configured.
+
+Usage:
+
+ipc_check.pl 
+
+	- simply checks for semaphores and shared memory being enabled
+	- if one or other is not enabled, appropriate "options" are provided
+	  to get it compiled into the kernel
+
+ipc_check.pl -B <# of buffers>
+
+	- checks to see if there are sufficient shared memory buffers to
+	  run the postmaster with a -B option as provided
+	- if insufficient buffers are provided, appropriate 'sysctl' commands,
+	  and instructions, are provided to the administrator to increase
+          them
+
+

contrib/ipc_check/ipc_check.pl

+#!/usr/bin/perl
+
+# Notes ... -B 1 == 8k
+
+if(@ARGV > 1) {
+  if($ARGV[0] eq "-B") {
+    $buffers = $ARGV[1];
+  }
+}
+
+if($buffers > 0) {
+  $kb_memory_required = $buffers * 8;
+}
+
+$shm = `sysctl kern.ipc | grep shmall`;
+( $junk, $shm_amt ) = split(/ /, $shm);
+chomp($shm_amt);
+$sem = `sysctl kern.ipc | grep semmap`;
+
+print "\n\n";
+if(length($shm) > 0) {
+  printf "shared memory enabled: %d kB available\n", $shm_amt * 4;
+  if($buffers > 0) {
+    if($kb_memory_required / 4 > $shm_amt) {
+      print "\n";
+      print "to provide enough shared memory for a \"-B $buffers\" setting\n";
+      print "issue the following command\n\n";
+      printf "\tsysctl -w kern.ipc.shmall=%d\n", $kb_memory_required / 4;
+      print "\nand add the following to your /etc/sysctl.conf file:\n\n";
+      printf "\tkern.ipc.shmall=%d\n", $kb_memory_required / 4;
+    } else {
+      print "\n";
+      print "no changes to kernel required for a \"-B $buffers\" setting\n";
+    }
+  }
+} else {
+  print "no shared memory support available\n";
+  print "add the following option to your kernel config:\n\n";
+  print "\toptions        SYSVSHM\n\n";
+}
+
+print "\n==========================\n\n";
+if(length($sem) > 0) {
+  print "semaphores enabled\n";
+} else {
+  print "no semaphore support available\n";
+  print "add the following option to your kernel config:\n\n";
+  print "\toptions        SYSVSEM\n\n";
+}
+
+