OPM RPG 中的示例: 访问字段值 (初始库列表)
此 OPM RPG 程序访问可变长度数组。 可变长度数组是作业描述的初始库列表。
作业描述格式 JOBD0100 格式的初始库列表字段的讨论指示初始库列表字段是每个条目 11 个字节，其中每个条目都是后跟空白的库名。 根据为初始库列表命名的库数，实际使用的空间量会有所不同 (按 11 的倍数)。
格式在初始库列表的 Offset 列中没有条目。 它可能以偏移量 390 开始，但不依赖于此偏移量值。 例如，如果将新字段添加到作业描述格式，那么可能将其放置在偏移量 390 处，并且将转移初始库列表信息。
要访问初始库列表字段，请使用以下格式的字段:
如果您以格式使用这些字段值，而不是静态地编码偏移量和多个库，那么即使在格式中定义了更多作业描述属性，您的程序也可以在业务计算系统的任何未来发行版上工作。 这是确保与未来发行版兼容的重要方法。 每当您为条目列表编写代码时，请使用此方法。
以下 RPG 代码为在初始库列表字段中找到的每个库发送一条消息。 异常由 RPG 程序处理。 虽然库名不能超过 10 个字节，但每个条目的长度为 11 个字节。
注: 通过使用代码示例，您同意 代码许可证和免责声明信息的条款。
I*****************************************************************
I*****************************************************************
I*
I*Program Name: JOBDAPI
I*
I*Language: OPM RPG
I*
I*Descriptive Name: Get Job Description
I*
I*Description: This sample program shows the correct
I* way of using the offset in a user space in RPG.
I*
I*Header Files Included: QUSEC - Error Code Parameter
I* (Copied into Program)
I* QWDRJOBD - Retrieve Job Description API
I* (Copied into Program)
I*
I*****************************************************************
I*****************************************************************
I*
I* Error Code Parameter Include for the APIs
I*
I* The following QUSEC include is copied into this program
I* so that the variable-length field can be defined as
I* fixed length.
I*
I*
I*** START HEADER FILE SPECIFICATIONS ****************************
I*
I*Header File Name: H/QUSEC
I*
I*Descriptive Name: Error Code Parameter.
I*
I*5763-SS1, 5722-SS1 (C) Copyright IBM Corp. 1994, 2001
I*All rights reserved.
I*US Government Users Restricted Rights -
I*Use, duplication or disclosure restricted
I*by GSA ADP Schedule Contract with IBM Corp.
I*
I*Licensed Materials-Property of IBM
I*
I*
I*Description: Include header file for the error code parameter.
I*
I*Header Files Included: None.
I*
I*Macros List: None.
I*
I*Structure List: Qus_EC_t
I*
I*Function Prototype List: None.
I*
I*Change Activity:
I*
I*CFD List:
I*
I*FLAG REASON LEVEL DATE PGMR CHANGE DESCRIPTION
I*---- ------------ ----- ------ --------- ----------------------
I*$A0= D2862000 3D10 931201 DPOHLSON: New Include
I*
I*End CFD List.
I*
I*Additional notes about the Change Activity
I*End Change Activity.
I*** END HEADER FILE SPECIFICATIONS ******************************
I*****************************************************************
I*Record structure for Error Code Parameter
I**** ***
I*NOTE: The following type definition defines only the fixed
I* portion of the format. Varying-length field exception
I* data is not defined here.
I*****************************************************************
IQUSBN DS
I* Qus EC
I B 1 40QUSBNB
I* Bytes Provided
I B 5 80QUSBNC
I* Bytes Available
I 9 15 QUSBND
I* Exception Id
I 16 16 QUSBNF
I* Reserved
I* Varying length, had to define len
I 17 100 QUSBNG
I*
I* Retrieve Job Description API Include
I*
I* The following QWDRJOBD include is copied into this program
I* so that the variable-length field can be defined as fixed
I* length.
I*
I*
I*** START HEADER FILE SPECIFICATIONS ****************************
I*
I*Header File Name: H/QWDRJOBD
I*
I*Descriptive Name: Retrieve Job Description Information API
I*
I*5763-SS1, 5722-SS1 (C) Copyright IBM Corp. 1994, 2001
I*All rights reserved.
I*US Government Users Restricted Rights -
I*Use, duplication or disclosure restricted
I*by GSA ADP Schedule Contract with IBM Corp.
I*
I*Licensed Materials-Property of IBM
I*
I*
I*Description: The Retrieve Job Description Information API
I* retrieves information from a job description
I* object and places it into a single variable in the
I* calling program.
I*
I*Header Files Included: None.
I*
I*Macros List: None.
I*
I*Structure List: Qwd_JOBD0100_t
I*
I*Function Prototype List: QWDRJOBD
I*
I*Change Activity:
I*
I*CFD List:
I*
I*FLAG REASON LEVEL DATE PGMR CHANGE DESCRIPTION
I*---- ------------ ----- ------ --------- ----------------------
I*$A0= D2862000 3D10 940424 ROCH: New Include
I*
I*End CFD List.
I*
I*Additional notes about the Change Activity
I*End Change Activity.
I*** END HEADER FILE SPECIFICATIONS ******************************
I*****************************************************************
I*Prototype for QWDRJOBD API
I*****************************************************************
I 'QWDRJOBD' C QWDBGB
I*****************************************************************
I*Type Definition for the JOBD0100 format.
I**** ***
I*NOTE: The following type definition defines only the fixed
I* portion of the format. Any varying-length fields have
I* to be defined by the user.
I*****************************************************************
IQWDBH DS 5000
I* Qwd JOBD0100
I B 1 40QWDBHB
I* Bytes Returned
I B 5 80QWDBHC
I* Bytes Available
I 9 18 QWDBHD
I* Job Description Name
I 19 28 QWDBHF
I* Job Description Lib Name
I 29 38 QWDBHG
I* User Name
I 39 46 QWDBHH
I* Job Date
I 47 54 QWDBHJ
I* Job Switches
I 55 64 QWDBHK
I* Job Queue Name
I 65 74 QWDBHL
I* Job Queue Lib Name
I 75 76 QWDBHM
I* Job Queue Priority
I 77 86 QWDBHN
I* Hold Job Queue
I 87 96 QWDBHP
I* Output Queue Name
I 97 106 QWDBHQ
I* Output Queue Lib Name
I 107 108 QWDBHR
I* Output Queue Priority
I 109 118 QWDBHS
I* Printer Device Name
I 119 148 QWDBHT
I* Print Text
I B 149 1520QWDBHV
I* Syntax Check Severity
I B 153 1560QWDBHW
I* End Severity
I B 157 1600QWDBHX
I* Message Log Severity
I 161 161 QWDBHY
I* Message Log Level
I 162 171 QWDBHZ
I* Message Log Text
I 172 181 QWDBH0
I* Log CL Programs
I 182 191 QWDBH1
I* Inquiry Message Reply
I 192 204 QWDBH2
I* Device Recovery Action
I 205 214 QWDBH3
I* Time Slice End Pool
I 215 229 QWDBH4
I* Accounting Code
I 230 309 QWDBH5
I* Routing Data
I 310 359 QWDBH6
I* Text Description
I 360 360 QWDBH7
I* Reserved
I B 361 3640QWDBH8 (1)
I* Offset Initial Lib List
I B 365 3680QWDBH9 (2)
I* Number Libs In Lib list
I B 369 3720QWDBJB
I* Offset Request Data
I B 373 3760QWDBJC
I* Length Request Data
I B 377 3800QWDBJH
I* Job Message Queue Max Size
I 381 390 QWDBJJ
I* Job Message Queue Full Actio
I* 391 391 QWDBJD
I*
I* Varying length
I* 392 402 QWDBJF
I*
I* Varying length
I* 403 403 QWDBJG
I*
I*
I* Command String Data Structure
I*
ICMDSTR DS
I I 'SNDMSG MSG(''LIBRARY- 1 22 CMD1
I ' - '
I 23 32 LIB
I I ''') TOUSR(QPGMR)' 33 47 CMD2
I*
I* Miscellaneous Data Structure
I*
I DS
I I 5000 B 1 40RCVLEN
I I 0 B 5 80X
I I 'JOBD0100' 9 16 FORMAT
C*
C* Beginning of Mainline
C*
C* Two parameters are being passed into this program.
C*
C *ENTRY PLIST
C PARM JOBD 10
C PARM JOBDL 10
C*
C* Move the two parameters passed into LFNAM.
C*
C JOBD CAT JOBDL LFNAM 20
C*
C* Error code Parameter is set to 100
C*
C Z-ADD100 QUSBNB
C*
C* Instead of specifying 'QWCRJOBD', I could have used the
C* constant QWDBGB that was defined in the QWDRJOBD include.
C*
C CALL 'QWDRJOBD'
C PARM QWDBH Receiver Var.
C PARM RCVLEN Length RCVVAR
C PARM FORMAT Format Name
C PARM LFNAM Qual. Job Desc
C PARM QUSBN Error Code
C* See if any errors were returned in the error code parameter.
C EXSR ERRCOD
C*
C N01 Z-ADD47 LENSTR 155
C*
C N01 QWDBH8 ADD 1 X
C N01 1 DO QWDBH9
C 10 SUBSTQWDBH:X LIB
C*
C* Let's tell everyone what the library value is.
C*
C CALL 'QCMDEXC'
C PARM CMDSTR
C PARM LENSTR
C ADD 11 X
C X IFGE RCVLEN
C LEAVE
C ENDIF
C ENDDO
C*
C SETON LR
C RETRN
C*
C* End of MAINLINE
C*
C*
C* Subroutine to handle errors returned in the error code
C* parameter.
C*
C ERRCOD BEGSR
C QUSBNC IFGT 0
C SETON 01 Error on API Call
C*
C* Process errors returned from the API.
C*
C END
C ENDSR
注: 访问计数并比较要处理的库的确切数目很重要。 如果不检查库的确切数目，那么可以开始以下一组信息的格式访问信息 (在此示例中，它可能是请求数据值)。
此程序示例的输出如下所示:
+--------------------------------------------------------------------------------+
| |
| Display Messages |
| |
| System: GENSYS90 |
| Queue . . . . . : QPGMR Program . . . . : *DSPMSG |
| Library . . . : QUSRSYS Library . . . : |
| Severity . . . : 00 Delivery . . . : *HOLD |
| Type reply (if required), press Enter. |
| LIBRARY - SMITH |
| From . . . : SMITH 07/23/94 12:29:38 |
| LIBRARY - QTEMP |
| From . . . : SMITH 07/23/94 12:29:38 |
| LIBRARY - QGPL |
| From . . . : SMITH 07/23/94 12:29:38 |
| LIBRARY - QBLDCPF |
| From . . . : SMITH 07/23/94 12:29:38 |
| LIBRARY - UTIL |
| From . . . : SMITH 07/23/94 12:29:38 |
| LIBRARY - OPENTEST |
+--------------------------------------------------------------------------------+
初始库列表字段的处理是您将在许多 API 中找到的典型内容。