This is working fine for me. 

#!/bin/Perl

use warnings;

if (@ARGV < 4) {
    print ("you need to provide 4 arguments\n\t4th argument is file to
+ parse");
    exit;
}

openfile(@ARGV);

sub openfile {
    print $_[3],"\n";
    open FILE1,">$_[0]" || die "could not open $_[1]\n";
    open FILE2,">$_[1]" || die "could not open $_[2]\n";
    open FILE3,">$_[2]" || die "could not open $_[3]\n";
    open FILE4,"<$_[3]" || die "could not open $_[4]\n";
    
    while (<FILE4>) {
        print $_;    
    }
}

[download]

Result: 

perl "E:\perl_TK\OpenFiles1.pl" a b c "e:\\territory20100713.sql"
Process started >>>
Name "main::FILE3" used only once: possible typo at E:\perl_TK\OpenFil
+es1.pl line 16.
Name "main::FILE1" used only once: possible typo at E:\perl_TK\OpenFil
+es1.pl line 14.
Name "main::FILE2" used only once: possible typo at E:\perl_TK\OpenFil
+es1.pl line 15.
e:\\territory20100713.sql
-- MySQL dump 10.13  Distrib 5.1.37, for Win32 (ia32)
--
-- Host: localhost    Database: territory
-- ------------------------------------------------------
-- Server version    5.1.37-community

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY
+_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO
+' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

--
-- Table structure for table `address`
--

DROP TABLE IF EXISTS `address`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `address` (
  `ID` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `Territory` varchar(45) NOT NULL,
  `Colonia` varchar(45) NOT NULL,
  `Street` varchar(60) NOT NULL,
  `Number` varchar(20) NOT NULL,
  `Lang` varchar(10) NOT NULL,
  `Notes` varchar(100) NOT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=2302 DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Dumping data for table `address`
--

LOCK TABLES `address` WRITE;
/*!40000 ALTER TABLE `address` DISABLE KEYS */;
INSERT INTO `address` VALUES (1,'','1-¦ de Mayo','Av. 1-¦ de Mayo','23
+9','Eng',''),(2,'','1-¦ de /*!40000 ALTER TABLE `address1` ENABLE KEY
+S */;
UNLOCK TABLES;

--
-- Table structure for table `streets`
--

DROP TABLE IF EXISTS `streets`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `streets` (
  `ID` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `Territory` varchar(45) NOT NULL,
  `Colonia` varchar(45) NOT NULL,
  `Street` varchar(60) NOT NULL,
  PRIMARY KEY (`ID`)
) ENGINE=InnoDB AUTO_INCREMENT=850 DEFAULT CHARSET=latin1;
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Dumping data for table `streets`
--

LOCK TABLES `streets` WRITE;
/*!40000 ALTER TABLE `streets` DISABLE KEYS */;
/*!40000 ALTER TABLE `streets` ENABLE KEYS */;
UNLOCK TABLES;

--
-- Temporary table structure for view `territoy_list`
--

DROP TABLE IF EXISTS `territoy_list`;
/*!50001 DROP VIEW IF EXISTS `territoy_list`*/;
SET @saved_cs_client     = @@character_set_client;
SET character_set_client = utf8;
/*!50001 CREATE TABLE `territoy_list` (
  `Territory` varchar(45),
  `Colonia` varchar(45),
  `Street` varchar(60),
  `Number` varchar(20),
  `Name` varchar(100),
  `Notes` varchar(100),
  `Lang` varchar(10),
  `Pub` varchar(5),
  `S_ID` varchar(45)
) ENGINE=MyISAM */;
SET character_set_client = @saved_cs_client;

--
-- Dumping routines for database 'territory'
--
/*!50003 CREATE*/ /*!50020 DEFINER=`gene`@`%`*/ /*!50003 FUNCTION `act
+uliza`(te CHAR(64), co CHAR
-- Dump completed on 2010-07-13 16:17:07
<<< Process finished.

[download]

In reply to Re: opened file being overwritten by Generoso
in thread opened file being overwritten by perishowl

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