[20210920]bbed的assign命令.txt

--//在windows下使用bbed的assign,發現沒有linux下遇到的問題，做一個記錄。

D:\tools\bbed>ver
Microsoft Windows XP [版本 5.1.2600]

BBED> info all
File# Name                     Size(blks)
----- ----                     ----------
     7 d:\tools\bbed\tea01.dbf           0

BBED> set dba 7,140
        DBA             0x01c0008c (29360268 7,140)

BBED> x /rnccntnnn dba 7,140 *kdbr[0]
rowdata[529]                                @8150
------------
flag@8150: 0x2c (KDRHFL, KDRHFF, KDRHFH)
lock@8151: 0x00
cols@8152:    8

col    0[3] @8153: 7369
col    1[5] @8157: SMITH
col    2[5] @8163: CLERK
col    3[3] @8169: 7902
col    4[7] @8173: 1980-12-17 00:00:00
col    5[2] @8181: 800
col    6[0] @8184: *NULL*
col    7[2] @8185: 20

BBED> p dba 7,140 kcbh.bas_kcbh
ub4 bas_kcbh                                @8        0x15055972

BBED> assign 8=0xf5055972
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
ub4 bas_kcbh                                @8        0xf5055972
--//第1位大於0x8.

BBED> p dba 7,140 kcbh.bas_kcbh
ub4 bas_kcbh                                @8        0xf5055972
--//可以發現windows下的bbed使用assign沒有任何問題，難道當時在linux測試有什麼細節我沒有注意嗎？
--//重複在linux下的測試如下：

SCOTT@book> @ ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

SCOTT@book> create table empx as select * from emp;
Table created.

SCOTT@book> select rowid from empx where rownum=1;
ROWID
------------------
AAAW4gAAEAAAAmjAAA

SCOTT@book> @ rowid AAAW4gAAEAAAAmjAAA
    OBJECT       FILE      BLOCK        ROW ROWID_DBA            DBA                  TEXT
---------- ---------- ---------- ---------- -------------------- -------------------- ----------------------------------------
     93728          4       2467          0 0x10009A3           4,2467               alter system dump datafile 4 block 2467

SCOTT@book> alter system checkpoint ;
System altered.

--//使用bbed修改:
BBED> set dba 4,2467
        DBA             0x010009a3 (16779683 4,2467)

BBED> p /x dba 4,2467 kcbh.wrp_kcbh
ub2 wrp_kcbh                                @12       0x0003

BBED> p /x dba 4,2467 kcbh.bas_kcbh
ub4 bas_kcbh                                @8        0x7fa46d5f

BBED> assign 12=2;
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
ub2 wrp_kcbh                                @12       0x0002

BBED> p /x dba 4,2467 kcbh.wrp_kcbh
ub2 wrp_kcbh                                @12       0x0002

BBED> assign 8=0x8fa46d5f
BBED-00207: invalid offset specifier (8fa46d5f)

BBED> assign 8=0x6fa46d5f
ub4 bas_kcbh                                @8        0x6fa46d5f

--//可以發現修改第1位是大於0x8,就出現問題.提示BBED-00207.換另外的方式:
BBED> assign kcbh.bas_kcbh=0x7fa46d5f
ub4 bas_kcbh                                @8        0x7fa46d5f

BBED> assign kcbh.bas_kcbh=0x8fa46d5f
BBED-00207: invalid offset specifier (8fa46d5f)

--//同樣報錯.
--//0x8fa46d5f = 2409917791

BBED> assign kcbh.bas_kcbh=2409917791
BBED-00207: invalid offset specifier (2409917791)

BBED> assign kcbh.bas_kcbh=409917791
ub4 bas_kcbh                                @8        0x186ed95f

BBED> assign kcbh.bas_kcbh=0x87146111
BBED-00206: out of range offset (87146111)

BBED> assign kcbh.bas_kcbh=0x8714611a
BBED-00207: invalid offset specifier (8714611a)

--//還可以發現一個奇怪的現象,如果16進位制全部數字不包括a-f,提示是BBED-00206.不是BBED-00207.

BBED> assign kcbh.bas_kcbh=0x7fa46d5f
ub4 bas_kcbh                                @8        0x7fa46d5f

BBED> assign 8=0x7fa46d5f
ub4 bas_kcbh                                @8        0x7fa46d5f

--//只要第一位不是0x8,兩種方式都可以正常執行.很明顯這個是bbed的bug.
BBED> assign kcbh.bas_kcbh=-1
BBED-00217: unable to assign: (-1) is out of range (0, 4294967295)

BBED> assign 8=-1
BBED-00217: unable to assign: (-1) is out of range (0, 4294967295)

--//最大值可以是4294967295,4294967295 = 0xffffffff,很明顯前面的值沒有操作這個範圍.

BBED> assign 8=4294967295
BBED-00207: invalid offset specifier (4294967295)

BBED> assign kcbh.bas_kcbh=4294967295
BBED-00207: invalid offset specifier (4294967295)

BBED> assign kcbh.bas_kcbh=0x7fffffff
ub4 bas_kcbh                                @8        0x7fffffff

BBED> assign 8=0x7ffffffe
ub4 bas_kcbh                                @8        0x7ffffffe

--//看來是bug確定無疑,如果出現這種情況,修改只能使用modify,而modify必須考慮大小頭問題,這樣就比較麻煩了.
--//比如要修改為0x8fa46d5f,顛倒過來就是 5f6da48f.

BBED> modify /x 5f6da48f offset 8
Warning: contents of previous BIFILE will be lost. Proceed? (Y/N) y
File: /mnt/ramdisk/book/users01.dbf (4)
Block: 2467     Offsets:    8 to   11    Dba:0x010009a3
--------------------------------
5f6da48f

<128 bytes per line>

BBED> p /x dba 4,2467 kcbh.wrp_kcbh
ub2 wrp_kcbh                                @12       0x0002

BBED> p /x dba 4,2467 kcbh.bas_kcbh
ub4 bas_kcbh                                @8        0x8fa46d5f

--//modify也有1個缺點.比如修改為0x8fa46d8f,顛倒過來就是 8f6da48f.

BBED> modify /x 8f6da48f offset 8
BBED-00209: invalid number (8f6da48f)

--//如果4位修改第一位也是不能大於0x8,不然也報錯,必須分開修改,

BBED> modify /x 8f6d offset 8
File: /mnt/ramdisk/book/users01.dbf (4)
Block: 2467    Offsets:    8 to   11    Dba:0x010009a3
--------------------------------
8f6da48f

<128 bytes per line>

BBED> modify /x a48f offset 10
File: /mnt/ramdisk/book/users01.dbf (4)
Block: 2467     Offsets:   10 to   13   Dba:0x010009a3
--------------------------------
a48f0200

<128 bytes per line>

BBED> p /x dba 4,2467 kcbh.bas_kcbh
ub4 bas_kcbh                                @8        0x8fa46d8f

--//或者這樣修改:
BBED> modify /x 8f6da4 offset 8
File: /mnt/ramdisk/book/users01.dbf (4)
Block: 2467      Offsets:    8 to   11     Dba:0x010009a3
--------------------------------
8f6da48f

<128 bytes per line>

BBED> modify /x 8f offset 11
File: /mnt/ramdisk/book/users01.dbf (4)
Block: 2467       Offsets:   11 to   14    Dba:0x010009a3
--------------------------------
8f020002
<128 bytes per line>

BBED> p /x dba 4,2467 kcbh.bas_kcbh
ub4 bas_kcbh                                @8        0x8fa46d8f

--//總之如果真正遇到這樣的情況處理起來在linux下相對麻煩.
--//收尾還原;

BBED> assign 8=0x7fa46d5f
ub4 bas_kcbh                                @8        0x7fa46d5f

BBED> assign 12=2
ub2 wrp_kcbh                                @12       0x0002

BBED> sum
Check value for File 4, Block 2467:
current = 0xfb68, required = 0xfb69
--//嗯,檢查和不對.噢改錯了.
BBED> assign 12=3
ub2 wrp_kcbh                                @12       0x0003

BBED> sum
Check value for File 4, Block 2467:
current = 0xfb68, required = 0xfb68

--//OK沒有問題.

[20210920]bbed的assign命令.txt

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