fig11_05.pl

来自「PERL语言资料 可以用于PERL程序设计」· PL 代码 · 共 33 行

#!/usr/bin/perl
# Fig. 11.5: fig11_05.pl
# Renaming a file before accidental deletion

use warnings;
use strict;

if ( -e 'file.txt' ) {
   print( "Do you want to write over file.txt? (yes or no): " );
   chomp( my $response = <STDIN> );
   rename( 'file.txt', 'file.old' )
      or die( "Error renaming : $!" )
         if ( $response eq 'no' );
}

open( FILE, ">file.txt" ) or die( "Error opening: $!" );
print( FILE "A copy of file.txt is saved in file.old.\n" );
close( FILE ) or die( "Cannot close: $!" );

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