#!/bin/perl
#
# Script:       global-replace.pl
# Description:  Ask user for key-pairs to replace in multiple files.
#
# Version:      2.0
# Last Update:  06 February 2002
# Written by:   Dusan U. Baljevic dusan.baljevic@ieee.org
#
# Copyright 2002-2014 Dusan Baljevic
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
#
# Make the script tight.
#
$ENV{'PATH'}  = '/bin:/usr/bin:/usr/local/sbin';
$ENV{'SHELL'} = '/bin/sh' if $ENV{'SHELL'} ne '';
$ENV{'IFS'}   = '' if $ENV{'IFS'} ne '';

$login = getlogin || getpwuid($<);

use strict;
use POSIX 'uname';
use POSIX qw(locale_h);
use Term::ReadKey;
use File::Basename;
use Getopt::Std;
require Mail::Send;
use File::Copy;

# Abort the execution if not interactive.
#
if ( !I_am_interactive() ) {
    exit(1);
}

use vars qw($Groupname $Groupowner $Username $Setpwuid
  $answer $DIRN @userinput @Extraarr $Oldstring $Newstring
  $fh $Oldfile $Newfile $cnt $LINE $Onerecord @Onerecord $RecipientX
  $opt_d $opt_a $opt_f $Findcomm $Arr $def $Commandname @find $msg $header @values
  @VALIDARRAY $login $LC_CTYPE $input $Root_check $Oner @Oner
  $Usage $Defext $Defdir $Extension $Olds $Fullsearch $News @Onemore);

setlocale( LC_CTYPE, "en_AU.ISO8859-1" );

# Flag to enforce that root cannot run the script.
#
$Root_check = 1;

# Effective UID
#
#if ($Root_check && $> == 0) {
#
# Real UID
#
#if ($Root_check && $< == 0) {
#
#if ($Root_check && ($login = "root")) {
#	print "ERROR: You should not be running this as root!\n";
#	exit(1);
#}

$Defext = "txt";
$Defdir = "/home/users1";

# Directory with files to replace.

$Commandname = basename($0);
$Usage       = "USAGE: $Commandname [-d /dir/path] [-f file-extension].
       $Commandname [-d /dir/path] -a
       OPTIONS
       -d search_directory (if not defined, default value is $Defdir)  
       -f file_extension (if not defined, default value is $Defext) 
       -a search all files in given directory\n";
getopts("d:f:a") or die "$Usage";

if ($opt_d) {
    if ( grep( /^\//, $opt_d ) && ( -d "$opt_d" ) ) {
        $DIRN = "$opt_d";
    }
    else {
        print "ERROR: Bad directory definition \"$opt_d\".\n";
        die "$Usage";
    }
}
else {
    $DIRN = "$Defdir";
}

if ($opt_f) {
    if ( $opt_f =~ /^([-\@:\w.]+)$/ ) {
        $Extension = "$opt_f";
    }
    else {
        print "ERROR: Bad file extension definition \"$opt_f\".\n";
        die "$Usage";
    }
}
else {
    $Extension = "$Defext";
}

if ($opt_a) {
    $Fullsearch = "$opt_a";
    $Extension  = "No extensions - full directory search!";
}

# Owner of files.
#
$Groupname  = "usergrp1";
$Username   = "user1";
$Groupowner = getgrnam($Groupname);
$Setpwuid   = getpwnam($Username);

# Who will receive warnings via email?
#
$RecipientX = "sysadmin";

sub Send_warn() {
    $msg = new Mail::Send;
    $msg->to("$RecipientX");
    $msg->subject("WARNING: Change permissions on $Oldfile failed!");
    $msg->set( $header, @values );
    $msg->add( $header, @values );
    $msg->delete($header);
    $fh = $msg->open;
    print $fh "Pathfind Admins/Operations: Check $Oldfile IMMEDIATELY.\n";
    print $fh "File $Oldfile should have:\n";
    print $fh "\t\tPermissions:     775\n";
    print $fh "\t\tOwnership:       $Setpwuid ($Username)\n";
    print $fh "\t\tGroupOwnership:  $Groupowner ($Groupname)\n";
    $fh->close;
}

# Default mode for script execution.
# "n" stands for "do not run".
#
$def = "n";
undef $answer;

print "\nNOTE: Welcome to global parameter replacement in $DIRN.\n";
print "NOTE: Do you want to proceed (Y|N) (default is N)?\n";

# Ask user to confirm or aborth the script execution.
# In CBREAK mode, no need to type in <RETURN> key.
# Wait three seconds for user input. If nothing comes,
# assume "N" and quit.
#
&Raw_Term_Mode;

if ( lc("$answer") eq "$def" ) {
    print "\nNOTE: Aborting global parameter replacement at your request.\n";
    exit(0);
}

print
  "\n\nNOTE: Type in space-separated key-pair values, one set per line.\n";
print "NOTE: Valid characters are: a-z A-Z 0-9 _ - : \@ \$ /\n";
print
"NOTE: Type in End-Of-File (Unix: CTRL-D) on a separate line when finished.\n";
print "EXAMPLE: newlove_2 newstring
attmtt aemt
l0ve376 \$BLAH_CURRENT
CTRL-D\n\n";

my @userinput;
chomp( @userinput = <STDIN> );

# Print all choices for user and ask to confirm.
#
local @Onemore = @userinput;
print "\n\nSUMMARY: You have chosen these values:

Directory: $DIRN\n
File Extension: $Extension\n";
while (@Onemore) {
    ($Oner) = splice( @Onemore, 0, 1 );
    ( $Olds, $News ) = split( /\s+/, $Oner );
    chomp($Olds);
    chomp($News);
    if (   ( $Olds =~ /^([-\/\@\$\:\w.]+)$/ )
        && ( $News =~ /^([-\/\@\$:\w.]+)$/ ) )
    {
        print "String \"$Olds\" to be replaced by \"$News\"\n";
        push( @VALIDARRAY, $Olds );
        push( @VALIDARRAY, $News );
    }
    else {
        print
"ERROR: Strings \"$Olds\" and/or \"$News\" contain invalid character.\n";
    }
}

print "NOTE: Do you want to proceed (Y|N) (default is N)?\n";

&Raw_Term_Mode;

if ( lc("$answer") eq "$def" ) {
    print "\nNOTE: Aborting global parameter replacement at your request.\n";
    exit(0);
}

die "ERROR: Cannot cd to: $!\n" unless chdir $DIRN;

# We are looking for scripts with names $Extension.
#
if ( defined($Fullsearch) ) {
    $Findcomm = "find $DIRN -type f -print";
}
else {
    $Findcomm = "find $DIRN -type f -name '\*$Extension' -print";
}

open( FIND, "$Findcomm |" ) or die "Cannot find *$Extension files: $!\n";
@find = <FIND>;
close FIND;

foreach $Oldfile (@find) {
    chomp($Oldfile);
    if ( !( -T $Oldfile ) ) {
        print "WARN: \"$Oldfile\" is not a text file. Skipping it...\n";
        next;
    }
    else {
        print "\nINFO: Processing file $Oldfile...\n";
    }
    chomp($Oldfile);
    $Newfile = "${Oldfile}-NEW";
    open( OLD, "<$Oldfile" ) or die "ERROR: Can't open $Oldfile: $!";
    open( NEW, ">$Newfile" ) or die "ERROR: Can't open $Newfile: $!";

    #
    # Enforce file locks:
    # Shared lock (1) for reading from an old file.
    # Advisory exclusive lock (2) for writing into a new file.
    #
    flock( OLD, 1 );
    flock( NEW, 2 );

    while (<OLD>) {
        $LINE     = $_;
        @Extraarr = @VALIDARRAY;
        while (@Extraarr) {
            @Oner = splice( @Extraarr, 0, 2 );
            if ( $#Oner != 1 ) {
                print
                  "ERROR: Record @Oner does not have two words [OLD, NEW]\n";
            }
            else {
                ( $Oldstring, $Newstring ) = ( @Oner[0], @Oner[1] );
                $Oldstring =~ s/([\$])/\\$1/g;
                $LINE      =~ s#$Oldstring#$Newstring#g;
            }
        }
        print NEW $LINE;
        print "\tNew Line $LINE\n";
    }
    close OLD;
    close NEW;
    if ( -T $Newfile && -s $Newfile ) {
        if ( move( "$Newfile", "$Oldfile" ) ) {
            chmod 00775, $Oldfile;
            $cnt = chown $Setpwuid, $Groupowner, $Oldfile;
            if ( int($cnt) != 1 ) {
                &Send_warn;
            }
        }
        else {
            warn "ERROR: Move $Oldfile to $Newfile failed: $!\n";
        }
    }
}

# POSIX system
#
#sub I_am_interactive {
#       local *TTY;
#       open(TTY, "/dev/tty") or die "Can't open /dev/tty: $!";
#       open(TTY, "/dev/tty");
#       my $tpgrp = tcgetpgrp(fileno(TTY));
#       my $pgrp = getpgrp();
#       close(TTY);
#       print "Woila: it is intercative\n";
#       return ($tpgrp == $pgrp);
#
# We do not want interactive sessions.
#
#       exit(3);
#}

# non-POSIX system
#
sub I_am_interactive {
    return -t STDIN && -t STDOUT;
}

sub Raw_Term_Mode {
    ReadMode('cbreak');
    $answer = ReadKey(3);
    ReadMode('normal');
    $answer ||= $def;
}

exit(0);