MayaChemTools

   1 package FileIO::FileIO;
   2 #
   3 # File: FileIO.pm
   4 # Author: Manish Sud <msud@san.rr.com>
   5 #
   6 # Copyright (C) 2019 Manish Sud. All rights reserved.
   7 #
   8 # This file is part of MayaChemTools.
   9 #
  10 # MayaChemTools is free software; you can redistribute it and/or modify it under
  11 # the terms of the GNU Lesser General Public License as published by the Free
  12 # Software Foundation; either version 3 of the License, or (at your option) any
  13 # later version.
  14 #
  15 # MayaChemTools is distributed in the hope that it will be useful, but without
  16 # any warranty; without even the implied warranty of merchantability of fitness
  17 # for a particular purpose.  See the GNU Lesser General Public License for more
  18 # details.
  19 #
  20 # You should have received a copy of the GNU Lesser General Public License
  21 # along with MayaChemTools; if not, see <http://www.gnu.org/licenses/> or
  22 # write to the Free Software Foundation Inc., 59 Temple Place, Suite 330,
  23 # Boston, MA, 02111-1307, USA.
  24 #
  25 
  26 use strict;
  27 use Carp;
  28 use Exporter;
  29 use FileHandle;
  30 use ObjectProperty;
  31 
  32 use vars qw(@ISA @EXPORT @EXPORT_OK %EXPORT_TAGS);
  33 
  34 @ISA = qw(ObjectProperty Exporter);
  35 @EXPORT = qw();
  36 @EXPORT_OK = qw();
  37 
  38 %EXPORT_TAGS = (all  => [@EXPORT, @EXPORT_OK]);
  39 
  40 # Setup class variables...
  41 my($ClassName);
  42 _InitializeClass();
  43 
  44 # Class constructor...
  45 sub new {
  46   my($Class, %NamesAndValues) = @_;
  47 
  48   # Initialize object...
  49   my $This = {};
  50   bless $This, ref($Class) || $Class;
  51   $This->_InitializeFileIO();
  52 
  53   $This->_InitializeFileIOProperties(%NamesAndValues);
  54 
  55   return $This;
  56 }
  57 
  58 # Initialize object data...
  59 #
  60 sub _InitializeFileIO {
  61   my($This) = @_;
  62 
  63   # File name...
  64   $This->{Name} = '';
  65 
  66   # Read, write or append...
  67   $This->{Mode} = 'Read';
  68 
  69   # Open/close status...
  70   $This->{Status} = 0;
  71 
  72   # File handle returned by file open...
  73   $This->{FileHandle} = '';
  74 }
  75 
  76 # Initialize class ...
  77 sub _InitializeClass {
  78   #Class name...
  79   $ClassName = __PACKAGE__;
  80 
  81 }
  82 
  83 # Initialize object properties....
  84 sub _InitializeFileIOProperties {
  85   my($This, %NamesAndValues) = @_;
  86 
  87   my($Name, $Value, $MethodName);
  88   while (($Name, $Value) = each  %NamesAndValues) {
  89     $MethodName = "Set${Name}";
  90     $This->$MethodName($Value);
  91   }
  92 
  93   return $This;
  94 }
  95 
  96 # Close any open file...
  97 sub DESTROY {
  98   my($This) = @_;
  99 
 100   $This->Close();
 101 
 102   return $This;
 103 }
 104 
 105 # Set file name and make sure it's not already set...
 106 #
 107 sub SetName {
 108   my($This, $Name) = @_;
 109 
 110   if ($This->{Name}) {
 111     croak "Error: ${ClassName}->SetName: Can't set file name to $Name:  $This->{Name}...";
 112   }
 113 
 114   $This->{Name} = $Name;
 115 
 116   return $This;
 117 }
 118 
 119 # Open file using specified mode...
 120 #
 121 sub Open {
 122   my($This, $Mode) = @_;
 123 
 124   if ($This->{Status}) {
 125     croak "Error: ${ClassName}->Open: Can't open file $This->{Name}: It's already open...";
 126   }
 127 
 128   if (defined $Mode) {
 129     # Set mode...
 130     $This->SetMode($Mode);
 131   }
 132 
 133   # Get name and mode...
 134   my($Name);
 135   $Name = $This->{Name};
 136   $Mode = $This->_GetOpenMode();
 137 
 138   # Open the file using specified mode and store FileHandle...
 139   my($FileHandle);
 140   $FileHandle = new FileHandle("${Mode}${Name}");
 141   if (!defined $FileHandle) {
 142     croak "Error: ${ClassName}->Open: Can't open $Name:  $! ...";
 143   }
 144   $This->{FileHandle} = $FileHandle;
 145   $This->{Status} = 1;
 146 
 147   return $This;
 148 }
 149 
 150 # Close an open file...
 151 sub Close {
 152   my($This) = @_;
 153 
 154   if ($This->{Status}) {
 155     $This->{FileHandle}->close();
 156   }
 157   $This->{Status} = 0;
 158 
 159   return $This;
 160 }
 161 
 162 # Supported Mode values are: Read, Write, Append, <, >, >>, r, w, a
 163 #
 164 sub SetMode {
 165   my($This, $SpecifiedMode) = @_;
 166   my($Mode);
 167 
 168   if (!defined $SpecifiedMode) {
 169     $SpecifiedMode = 'Read';
 170   }
 171 
 172   MODE: {
 173     if ($SpecifiedMode =~ /^(Read|<|r)$/i) { $Mode = 'Read'; last MODE; }
 174     if ($SpecifiedMode =~ /^(Write|>|w)$/i) { $Mode = 'Write'; last MODE; }
 175     if ($SpecifiedMode =~ /^(Append|>>|a)$/i) { $Mode = 'Append'; last MODE; }
 176     croak "Error: ${ClassName}->SetMode: Specified mode value, $SpecifiedMode, is not valid: Supported values: Read, Write, Append, <, >, >>, r, w, a...";
 177   }
 178   $This->{Mode} = $Mode;
 179 
 180   return $This;
 181 }
 182 
 183 # Get mode values to be used for file open function: <, >, >>
 184 #
 185 sub _GetOpenMode {
 186   my($This) = @_;
 187   my($Mode);
 188 
 189   MODE: {
 190     if ($This->{Mode} =~ /^(Read|<|r)$/i) { $Mode = '<'; last MODE; }
 191     if ($This->{Mode} =~ /^(Write|>|w)$/i) { $Mode = '>'; last MODE; }
 192     if ($This->{Mode} =~ /^(Append|>>|a)$/i) { $Mode = '>>'; last MODE; }
 193     $Mode = '';
 194   }
 195   return $Mode;
 196 }
 197