From 48634510f32551bb3dac3e211c8fcfcaa14fb35c Mon Sep 17 00:00:00 2001
From: Andrew Ruthven <andrew@etc.gen.nz>
Date: Thu, 27 Dec 2007 22:11:56 +1300
Subject: [PATCH] Fix up handling of commands that are executable and add lots
 more debugging.

Back when I was using Spong at a previous job years ago, and again now that
I'm playing with it at home I ran into problems with lots of spong-network
processes all claming to be checking the same server and check.

I finally decided to dig into it.  In the current case it is because the
program wasn't executable and SafeExec wasn't working that out.  The
forked child was continuing to run for whatever reason.

This appears to work correctly now, I don't have ghost spong-network
processes hanging around anymore.
---
 src/lib/Spong/SafeExec.pm | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/src/lib/Spong/SafeExec.pm b/src/lib/Spong/SafeExec.pm
index 86f1e6d..abee8b1 100755
--- a/src/lib/Spong/SafeExec.pm
+++ b/src/lib/Spong/SafeExec.pm
@@ -16,13 +16,14 @@ sub safe_exec {
 
     $timeout = 15 if  $timeout <= 0;
 
+    main::debug("Going to run $cmd, timeout of $timeout", 10);
     my $pid = open(CMD, "-|");
 
     if ($pid) { # I'm the parent
-
         $message = "";
         eval {
-            local $SIG{'ALRM'} = sub { die };
+            local $SIG{'ALRM'} = sub { die "alarm\n" };
+            local $SIG{'PIPE'} = sub { die "pipe closed\n" };
             alarm($timeout);
 
             @output = <CMD>;
@@ -30,11 +31,17 @@ sub safe_exec {
             alarm(0);
         };
 
+        main::debug("After eval for $cmd", 10);
+        if ($@) {
+            main::debug("Timeout for $cmd triggered: $@", 10);
+        }
+
         close CMD or !$! or croak "Error closing CMD fh: $!";
         alarm(0);
 
         # Handle child process is not gone
         if ( kill 0,$pid ) {
+            main::debug("Child process that was running '$cmd' hasn't finished, terminating", 10);
             kill "INTR",$pid;  # Try control+C
             sleep 1;           # Give it time to die
 
@@ -48,7 +55,23 @@ sub safe_exec {
         }
 
     } else {
-        exec($cmd) || croak "cannot exec program $cmd: $!";
+        $0 = "$0 - (SafeExec)";
+        main::debug("Child process running '$cmd'", 10);
+        system($cmd);
+
+        if ($? == -1) {
+            carp "cannot execute '$cmd': $!";
+            exit -1;
+        } elsif ($? & 127) {
+            carp "'$cmd' failed with signal " . ($? & 127);
+            exit -1;
+        } elsif ($? != 0) {
+            main::log("Command '$cmd' return error code: " . $? >> 8);
+        }
+
+        main::debug("Child process finished '$cmd'", 10);
+
+        exit;
     }
 
    wantarray ? @output : join '', @output;
-- 
2.30.2