作者sqrt1089 (李崩子)
看板Perl
标题[问题] binary file 读取问题
时间Wed Feb 8 17:36:55 2012
有个binary file
以下是我code
#!/usr/bin/perl -w
use strict;
my $fn = shift;
my $n = shift;
my $v;
open FH, $fn or die;
seek FH, 8*($n-1), 0 or die; # since a double requires 8 bytes
read FH, $v, 8;
$v = unpack( 'd', $v );
print "$v\n";
执行 ./paly.pl file 50000
输出结果 0.227
改良成为一串的读取
use strict;
my $fn = shift;
my $n = shift;
my $end =shift;
my $v;
my @out;
open FH, $fn or die;
for ($n .. $end){
seek FH, 8*($_-1), 0 or die; # since a double requires 8 bytes
read FH, $v, 8;
$v = unpack( 'd', $v );
push (@out, $v);
}
print "@out\n";
执行 ./paly.pl file 50000 50010
输出结果 0.227 0.239 0.264 0.275 0.286 0.308 0.319 0.329 0.329 0.341 0.35
我想请问有没有其他方法一口气读 50000~50010 的字串
谢谢！
===============================================
上网查 有一个作法，但是try了後还是不行
是改写成 $v = unpack('d16',$v);
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