#!/usr/bin/perl -w
#---------------------------------------------------------------------
# Description: Improvied script to search for non-existent commands
# references in Upstart jobs. See:
#
#   https://bugs.launchpad.net/ubuntu/+source/upstart/+bug/912558
#
# Usage: Run the command as a non-root user. If it produces any output,
# you will be affected by the bug referenced above.
#
# Author: James Hunt <james.hunt@ubuntu.com>
# Date: 7 January 2012
#---------------------------------------------------------------------

use strict;

sub escape_shell_chars
{
  my $str = shift;
  $str =~ s/([;<>\*\|`&\$!#\(\)\[\]\{\}:'"])/\\$1/g;
  return $str;
}

sub contains_shell_meta_chars
{
  my $str = shift;
  my $copy = escape_shell_chars ($str);

  return $copy eq $str ? 0 : 1;
}

# use Upstarts default PATH
$ENV{PATH} = "/usr/local/sbin:/usr/local/bin:/usr/bin:/usr/sbin:/sbin:/bin";

foreach my $conf (`ls /etc/init/*`)
{
  my $file;
  my $cmd = undef;
  my $meta = 0;

  chomp ($conf);

  open (FILE, $conf) or die "failed to open file $conf, ";

  while (<FILE>)
  {
    chomp;
    if ($_ =~ /^(\s*exec\s*|\s*(pre|post)-(start|stop)\s*exec\s*)([^\s]*)/ )
    {
      $cmd = $4;

      if (contains_shell_meta_chars ($cmd))
      {
        $meta = 1;
        last;
      }
    }
  }

  next unless defined $cmd;
  next if $meta;

  my @a = split //, $cmd;
  my $first = (split //, $cmd)[0];

  if (($first eq q(/) or $first eq q(.)) and not `ls $cmd 2>/dev/null` )
  {
    print "absolute command $cmd not found\n";
  } elsif (not `which $cmd`)
  {
    print "relative command $cmd not found\n";
  }

  close (FILE);
}