!/usr/bin/perl -w use strict;  #print "please input a string/n"; #my $line = <STDIN>; #print $line;  #wirte a file open(FH, ">aa.txt") or die $!;  print FH "hello/n";#向文件寫入內容 print FH "OK/n";  close(FH);  #open a file open(FH, "aa.txt") or die $!; my @f = <FH>;#將文件內容讀出 print @f;  close(FH);