#!/usr/bin/perl -w
#################################################
# sarep 1.1 (991119) - Search and Replace tool  #
# (C)1999 Matthew Borowski <mkb@worldserve.net> #
# http://tarp.worldserve.net/software/          #
# ftp://ftp.worldserve.net/pub/sarep/           #
#################################################
# Package dependencies:
#   Text::CSV_XS used with the option -f to parse CSV files
# ftp://ftp.cpan.org/pub/CPAN/modules/by-category/11_String_Lang_Text_Proc/Text/Text-CSV_XS-0.20.tar.gz
#
# Reads files one line at a time and modifies the text, supports regular
# expressions. Works with wildcards, supports multiple files on command
# line. Run sarep with no arguments for help.
# 
# Changes from 1.0 to 1.1:
# Big thanks go once again to Andrey A. Chernov. Two patches by him:
# * sarep will now maintain file creation date on files it does not
#   modify. The previous code actually touched each file, thus resetting
#   the file date.
# * sarep now uses the perl locale support, so case insensitivity now 
#   works with non-english languages as well
#
# Changelog from 0.5 to 1.0:
#
# * Nice new version number!
# * New seperate -v (Verbose) and -vv (VeryVerbose) modes
# * SAREP now preserves file permissions when modifying files
# * TODO List: report number of changes made instead of number of 
#   lines changed.
#
# Many Thanks to the Contributors:
# Raphaël Rousseau <raph@alcove.fr>
# Andrey A. Chernov <ache@nagual.pp.ru>
# Doughnut <doughnut@doughnut.net>
# Thanks to Bert Vermeulen and the #LinuxOS guys
#
# Comments/questions appreciated. No flames, I'm a newbie programmer
# License: BSD License

use strict;
use locale;

my ($renametonormal, $option, $searchfor, $replacewith, $fromfile, $patterns, $verbose, $veryverbose,
$patternfile, $currentnum, $file, $occurrences, $line, $caseinsensitive, $escapemeta);
#START
#if no command-line argument, print usage info
&helpinfo if ($#ARGV eq -1);

# set defaults. If this gets any more complicated
# consider switching to Getopt::Std or Getopt::Long.
$renametonormal=1;    # Do we rename file to their initial name ?
$caseinsensitive = 0; # Is the search case sensitive ?
$escapemeta = 0;      # Do we escape metacharacters ?
$fromfile = 0;        # Do we take search and replace strings from a CSV file ?
$verbose = 0;         # Do we need verbosity ?
$veryverbose = 0;     # Do we want to be very verbose?

while (defined($ARGV[0]) && $ARGV[0] =~ /^-/) {
  $option = shift @ARGV;
  $renametonormal=0 if $option =~ /n/;
  $caseinsensitive = 1 if $option =~ /i/;
  $verbose = 1 if $option =~ /v/;
  #Very verbose mode implies standard verbose mode as well
  $verbose = 1 if $option =~ /vv/;
  $veryverbose = 1 if $option =~ /vv/;
  $escapemeta = 1 if $option =~ m#m#; 
  if ($option =~ /f/) {
  	$fromfile = 1;
	$patternfile = shift @ARGV;
	&helpinfo if (! -f $patternfile);
  }
  &helpinfo if ($option =~ /-[^vfinm]/) ;
}

if (!$fromfile) {
	#check if they included a search-string, if not exit
	&helpinfo if (!defined($searchfor = shift @ARGV));
	
	#check if they included a replace-string, if not exit
	&helpinfo if (!defined($replacewith = shift @ARGV));

	$patterns->{$searchfor} = $replacewith;
} else {
	require Text::CSV_XS;
	my $csv = Text::CSV_XS->new({'binary' => 1});
	my ($line);
	open (PATTERN, $patternfile) || die "Cannot open pattern file $patternfile : $!";
	while (defined ($line = <PATTERN>)) {
		if ($csv->parse($line)) {
			my @fields = $csv->fields;
			$patterns->{$fields[0]} = $fields[1];
		} else {
			my $err = $csv->error_input;
			die 'parse() failed in file '.$patternfile.' on argument: '.$err.'\n'; 
		}
	}
}

#check if they included at least ONE filename.
&helpinfo if !defined($ARGV[0]);

# Apply changes in each file
while (defined($file = shift @ARGV)) {
	&replace ($patterns, $file);
}


sub replace {
	my ($patterns, $file) = @_;
	my $fmode;
	my $ftime;
	my @st;
	
	
	# prepare to count number of changes made.
	$occurrences = 0;
	
	#print current file being sarep'ed.
	print "Processing file $file:" if $verbose;
	#open up the file, if it doesnt exist, print an error
	open(INFILE, "<$file") || die("Error: $file $!");
        if ($renametonormal) {
                if (@st = (stat(*INFILE))) {
                        $fmode = $st[2];
			$ftime = $st[9];
                } else {
                        die("Error: can't stat $file: $!");
                }
        }
	#now open up the filename with a .sarep extension.
	open(OUTFILE,">$file\.sarep") || die("Error: unable to create temporary .sarep file");
	
	#while INFILE still has lines, make $_ equal to the line, then 
	#search/replace it and write it to the OUTFILE. The $_ is removed from
	#INFILE, so when you go through the loop again, the next line is done.
	while(<INFILE>) {
		$line = $_;
		my ($searchfor, $replacewith);
		foreach $searchfor (keys %$patterns) {
			$replacewith = $patterns->{$searchfor};
			$searchfor = quotemeta($searchfor) if $escapemeta;
			$searchfor = '(?i)'.$searchfor if $caseinsensitive;
			#print current line being sarep'ed.
			print "\n \ts/$searchfor/$replacewith/g" if $veryverbose;
			#print out what string is being searched for and replaced with, and if
			#the results will be printed out to the filename, or to filename.sarep.
			if($renametonormal) { print ", output directly to file(s)." if $veryverbose; } 
			else { print ", output to .sarep file(s)." if $veryverbose; }
			$occurrences++ if $line =~ s/$searchfor/$replacewith/g;
		}
			print OUTFILE $line;
	}
    
	#close up the files...
	close OUTFILE;
	close INFILE;
	
	#if they didnt specify -n, then $renametonormal=1 (due to the if at the 
	#top_. so go ahead and rename the .sarep file to the normal filename.
	if($renametonormal){
		rename "$file\.sarep",$file;
                # chmod _after_ rename since rename clears s-bit on some system$
                if (chmod ($fmode, "$file") != 1) {
                        $fmode = sprintf "0%o", $fmode;
                        die("Error: can't chmod $fmode $file: $!");
                }
		if ($occurrences == 0) {
			if (utime (time, $ftime, "$file") != 1) {
				die("Error: can't set times for $file: $!");
			}
		}
	}

        print "\n" if $veryverbose;
	# I'd rather this said how many changes were made, but not tonight.
	print " $occurrences lines altered.\n" if $verbose;
}

#subroutine to print help
sub helpinfo {
  print STDERR "usage: $0 <options> search-string replace-string filename(s)\n";
  print STDERR "options:\n\t-n (create new files with .sarep extension)\n";
  print STDERR "\t-i (performs the search as case-insensitive)\n";
  print STDERR "\t-m (performs the search with metacharacters interpreted as normal ones)\n";
  print STDERR "\t-f <name of file>(takes search and replace strings from the file)\n";
  print STDERR "\t-v (verbose mode)\n";
  print STDERR "\t-vv (very verbose mode)\n";
  exit 1; # Exit with value different from 0 which means ERROR
}

#END