#!/usr/bin/tclsh
######################################################################
# Quick tcl script to pull pound entries for syslog files and strip  #
# any extra fluff from the start                                     #
# Mat Kovach mkovach at alal dot com                                 #
######################################################################

package require dns

proc err { reason } {

  puts stderr $reason

}

proc process_pound { line } {

  set split_line [split $line]
  if {[lindex $split_line 4] == "pound:"} {
    if {[regexp -nocase {^[a-z0-9]} [lindex $split_line 5] ]} {
      if { [regexp "(\[0-9]{1,3})\.(\[0-9]{1,3})\.(\[0-9]{1,3})\.(\[0-9]{1,3})" [lindex $split_line 6] all first second third fourth] } {
          set dns_tok [::dns::resolve $all -nameserver 127.0.0.1]
	  if {[::dns::status $dns_tok] == "ok"} {
              lset split_line 6 [::dns::name $dns_tok]
          }
          catch {::dns::cleanup $dns_tok}
      }
      puts [join [lrange $split_line 5 end]]
     }
  }

}

proc read_file { fp func } {

  while {[gets $fp line] >= 0} {
    $func $line
  }
  close $fp

}

proc check_file { filename } {

  set fp -1
  if {[catch {open $filename "r"} fp]} {
        err "Error reading $filename, $fp. Skipping file"
  }
  return $fp

}

proc file_list { files } {

  foreach file $files {
    if { [file isfile $file] && [file readable $file] } {
      set fp [ check_file $file ]
      if { $fp != -1 } {
        read_file $fp process_pound
      }
    } else {
      err "File is not readable or not a file, skipping $file"
    }
  } 

}

proc main { argv } {

  if { [llength $argv] == 0 } {
    read_file "stdin" process_pound
  } else {
    file_list $argv 
  }

}

main $argv