open( FH, "echo @args | myproc |" ) || die "flaming death $!"

  
 
  
 
User requests search by filling out web based form. 
Main CGI processes/validates request.  
If no errors: 
    Prepares HTML to state search in progress 
    Puts hidden variable in HTML form for timeout if process takes  
        too long 
    Sends HTML to User 
    Forks after HTML output to start search. 
    Form auto submits every 6 seconds to see if search is done 
      or process is taking longer than timeout setting in config 
      file. 
 
  
    Forked Search does this with passed parameters: 
        Queries LDAP server 
        Finds all Records matching search criteria 
        Parses each entry's x509 certificate entry (.cer format) 
        Evaluates if certificate will expire in month specified 
            in search criteria 
        Writes a .csv file on success 
        Any fatal error (can't open file, etc.) is written to 
           error file. 
 
  
    When Main CGI finds the existence of either the .csv or error 
    files, it processes them for display back to the browser. 
 
  
    Process is finished. 
 

   
# main thread would execute 
 
# Following is some pseudo code ... 
if (search is not in progress){ 
    get search criteria; 
    print 'waiting' html with flag set to indicate search has started 
    startSearch();  # once this runs, new thread is spawned and this one exits 12 lines down 
 
} 
else { 
    if (process output does not exist){ 
        redisplay some waiting html to user 
        that auto submits form again to check after 6 second wait 
    } 
    else { 
        process search results based on process output 
    } 
} 
 
  
exit; 
  
 
 
sub startSearch { 
 local $SIG{CHLD} = 'IGNORE'; 
 open( STDIN, "</dev/null"); 
 open( STDOUT, ">>/dev/null"); 
 open( STDERR, ">>../logs/daemon_logfile"); 
  
 fork and exit;   # main thread stops here and new thread resumes from this point 
 
  
 my @args = ("perl", "expSearch.pl"); 
 exec @args or print STDERR "[ ".localtime()." ] PID: $$ Can't perform search. Error: $!\n"; 
 
}