[PerlChina] Re: 16进制文件操作

感谢！
这种方法我有想过
但是 想知道 有没有 根据文件位置 s/$aims//的办法
或者其他办法 比如说 print一个空数据？
业余初学 望见谅

On 8月8日, 下午7时24分, Anthony WU <anthonywu...@gmail.com> wrote:
> 我把 seek 第二 及第三個參數寫反了，刪除是不能的，但你可以通過 先讀
> 0x00-0x8f 跳到0xb0再讀到EOF並把所取得的BYTES寫到新檔案
>
>
>
> -------- Original Message --------
> Subject: [PerlChina] Re: 16进制文件操作
> From: perlw01f <p3r1w...@gmail.com>
> To: PerlChina Mongers 讨论组 <perlchina@googlegroups.com>
> Date: 8/8/2009 10:42
> > 谢谢
> > perldoc -f seek的结论貌似跟这个不一样 ？
>
> > seek FILEHANDLE,POSITION,WHENCE
> > Sets FILEHANDLE's position, just like the "fseek" call of
> > "stdio". FILEHANDLE may be an expression whose value gives
> > the
> > name of the filehandle. The values for WHENCE are 0 to set
> > the
> > new position *in bytes* to POSITION, 1 to set it to the
> > current
> > position plus POSITION, and 2 to set it to EOF plus POSITION
> > (typically negative). For WHENCE you may use the constants
> > "SEEK_SET", "SEEK_CUR", and "SEEK_END" (start of the file,
> > current position, end of the file) from the Fcntl module.
> > Returns 1 upon success, 0 otherwise.
>
> > Note the *in bytes*: even if the filehandle has been set to
> > operate on characters (for example by using the ":utf8" open
> > layer), tell() will return byte offsets, not character
> > offsets
> > (because implementing that would render seek() and tell()
> > rather
> > slow).
>
> > If you want to position file for "sysread" or "syswrite",
> > don't
> > use "seek"--buffering makes its effect on the file's system
> > position unpredictable and non-portable. Use "sysseek"
> > instead.
>
> > Due to the rules and rigors of ANSI C, on some systems you
> > have
> > to do a seek whenever you switch between reading and
> > writing.
> > Amongst other things, this may have the effect of calling
> > stdio's clearerr(3). A WHENCE of 1 ("SEEK_CUR") is useful
> > for
> > not moving the file position:
>
> > seek(TEST,0,1);
>
> > This is also useful for applications emulating "tail -f".
> > Once
> > you hit EOF on your read, and then sleep for a while, you
> > might
> > have to stick in a seek() to reset things. The "seek"
> > doesn't
> > change the current position, but it *does* clear the end-of-
> > file
> > condition on the handle, so that the next "<FILE>" makes
> > Perl
> > try again to read something. We hope.
>
> > If that doesn't work (some IO implementations are
> > particularly
> > cantankerous), then you may need something more like this:
>
> > for (;;) {
> > for ($curpos = tell(FILE); $_ = <FILE>;
> > $curpos = tell(FILE)) {
> > # search for some stuff and put it into files
> > }
> > sleep($for_a_while);
> > seek(FILE, $curpos, 0);
> > }
>
> > 另外，您的code 我尝试了一下
> > seek ($fp, 0, 0x80);
> > print $fp "\x0";
> > 实际的效果是 00000000h这一行 第1和2字节变成了0 没有偏移？
> > 我自己尝试
> > seek ($fp, 16*8, 0x00);
> > print $fp "\x0";
> > 可以达到目的
>
> > 另外 我想请教 如何删除掉一部分内容呢 比如 0x90-0xb0
> > 谢谢
> > On 8月8日, 上午12时48分, Anthony WU <anthonywu...@gmail.com> wrote:
>
> >> 以你所說的操作大約是
> >> open (my $fp, '+<', 'x.dat');
> >> binmode ($fp);
> >> seek ($fp, 0, 0x80);
> >> print $fp "\x0";
> >> seek ($fp, 0, 0x82);
> >> print $fp "\x0";
> >> seek ($fp, 0, 0x84);
> >> print $fp "\x0";
> >> seek ($fp, 0, 0x86);
> >> print $fp "\x8B";
> >> seek ($fp, 0, 0x87);
> >> print $fp "\x8B";
> >> seek ($fp, 0, 0x88);
> >> print $fp "\x0A";
> >> seek ($fp, 0, 0x89);
> >> print $fp "\x0A";
> >> ....
> >> ....
> >> ....
> >> close ($fp);
>
> >> -------- Original Message --------
> >> Subject: [PerlChina] Re: 16进制文件操作
> >> From: perlw01f <p3r1w...@gmail.com>
> >> To: PerlChina Mongers 讨论组 <perlchina@googlegroups.com>
> >> Date: 7/8/2009 21:16
>
> >>> 都是在确定的位置
>
> >>> 如 00000080h 这一栏 第1 3 5 字节换为0 78换为8B 9 10 换为0A 还有一些其他的
>
> >>> On 8月7日, 下午9时04分, Anthony WU <anthonywu...@gmail.com> wrote:
>
> >>>> 你的字節是定位修改的嗎？有什麼規律的？
>
> >>>> -------- Original Message --------
> >>>> Subject: [PerlChina] Re: 16进制文件操作
> >>>> From: perlw01f <p3r1w...@gmail.com>
> >>>> To: PerlChina Mongers 讨论组 <perlchina@googlegroups.com>
> >>>> Date: 7/8/2009 20:56
>
> >>>>> 我有一个文件 x.dat，由x.rar.gz压缩而成 但是其中某些字节做了修改处理 现在的文件名是 a.dat
> >>>>> 现在 我想逆行操作，即
> >>>>> 先将a.date rename成x.rar.gz 然后利用ue修改某些字节 之后才能解压缩成x.date
>
> >>>>> 由于文件数量较多 且ue 16进制 修改也不是很方便
> >>>>> 所以想 用 perl实现
> >>>>> 谢谢
>
> >>>>> On 8月7日, 下午5时17分, cnhack TNT <cnhack...@gmail.com> wrote:
>
> >>>>>> 能举例说明你要做的事情么？
>
> >>>>>> 2009/8/7 perlw01f <p3r1w...@gmail.com>
>
> >>>>>>> perl中 有没有类似ultredit中那种直接转换成16进制进行操作的方法或者module
>
> >>>>>>> unpack是不是太费事了
>
> >>>> --
> >>>> Best Regards,
> >>>> Anthony WU
>
> >> --
> >> Best Regards,
> >> Anthony WU
>
> --
> Best Regards,
> Anthony WU
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