#!/usr/bin/perl
# replace Zenkaku space -> 2 spaces

## def
$Zspace = '(?:\xA1\xA1)'; #EUC-JP, 
#taken from http://www.din.or.jp/~ohzaki/perl.htm
$Zspace_sjis = '(?:\x81\x40)'; # SJIS 

## IO
print "Type extension of input files = ";
chop($suffix =<STDIN>);

## read current dir
@files = ();
opendir(DIR, ".");
@files = grep(/.$suffix/, readdir(DIR));
closedir(DIR);

print @files; # debug

## for each file
foreach $file (@files) {

#    `nkf -eLu $file > $file.euc`; ### if necessary
#open (DATA, "$file.euc"); ### when using the above line
open (DATA, "$file");
open (OUT, ">sp-$file");

# loop
while (<DATA>) {
    s/($Zspace)/  /g;
print;
print OUT;
}
}