1）文件读取的3中方法
按行读，存入标量
while (<FILE>) { print; }
按行读，存入数组
@array = <FILE>;
读入整个文件 ，存入标量
$string = do { local $/; <FILE>; };
2）读文件实例
open (EP,"/etc/passwd");
while (<EP>) {
chomp;
print "I saw $_ in the password file!\n";
}
while (<EP>) {
chomp;
print "I saw $_ in the password file!\n";
}
3）读写文件实例
open(IN,$a) || die "cannot open $a for reading: $!";
open(OUT,">$b") || die "cannot create $b: $!";
while (<IN>) { # read a line from file $a into $_
print OUT $_; # print that line to file $b
}
close(IN) || die "can't close $a: $!";
close(OUT) || die "can't close $b: $!";
open(OUT,">$b") || die "cannot create $b: $!";
while (<IN>) { # read a line from file $a into $_
print OUT $_; # print that line to file $b
}
close(IN) || die "can't close $a: $!";
close(OUT) || die "can't close $b: $!";
来自：http://yixf.name/2011/04/26/perl%E8%AF%BB%E5%8F%96%E6%96%87%E4%BB%B6%E4%B8%89%E6%B3%95/