The Save Interchange Data command allows you to interchange one or
more members in data interchange mode rather than Save/Restore mode.
This can be of particular advantage when interchanging source and
small data files between:
** Two different i5 Systems which are at different release levels
and the save to previous release support cannot be used.
** An i5 System and an S/38. An option exists to add or remove
the '38' entry and convert certain entries (e.g. CLP38
becomes CL).
See the later discussion about how to use the RSTICHDTA function on
an S/38.
The SAVICHDTA command writes one or more members into a physical file
separated by a uniquely identified record. You would normally use
one of the copy commands to copy the file to diskette, tape or send
this file to another system using DDM or some other communications
approach.
Assuming the other system is running i5/OS, you would normally copy
the file into a data base file and then use the RSTICHDTA command to
extract the data and make normal members.
Source files up to a length of 125 are supported. Data files up to a
length of 4500 bytes are supported. No logical files are allowed.
The record length size for data interchange is 125 bytes of data
followed by a blank and then a 2 byte control field or 128 byte
records. If the actual record size exceeds 125 bytes, multiple
records will appear in the interchange file for each actual data base
record. Record sizes less than 125 are handled properly. Most
source files will fit within 125 bytes. The only or last segment of
a record is padded to fill out the 125 bytes.
Because of this technique, SAVICHDTA is not as efficient as a save or
restore. It's advantage is that it does not have any Save/Restore
restrictions regarding which release can be used because it uses data
interchange format. You should restrict the use to small members
(e.g. source) or control files.
The files must exist on the system to use the RSTICHDTA command.
That is, if you used SAVICHDTA to save FILEA on one system, FILEA
must exist on the system that you do RSTICHDTA on. The members will
be added if they do not exist. If a member name exists, the data
will be replaced.
The commands use the ICHDTAP data base file which must be created.
The create command should specify:
CRTPF FILE(ICHDTAP)
RCDLEN(128)
SIZE(50000 10000 5)
TEXT('File used by SAV/RSTICHDTA')
Assume you want to move 3 source members from the standard source
file names (e.g. QCMDSRC, QCLSRC etc.) in library PRODUCTION and the
data base file PAYCTLP to another system using tape. You would
specify:
SAVICHDTA LIB(PRODUCTION) LIST((*CMD PAYROLL)(*CLP PAYROLLC) +
(*RPG PAYROLL)(PAYCTLP *ALL))
CPYTOTAP FROMFILE(ICHDTAP) TOFILE(QTAPE) TODEV(TAP01)
On the target system, you want to copy the tape media into the
ICHDTAP file and then restore the source members back to the standard
source file names and the PAYCTLP file into library PRODUCTION. You
would specify:
CPYFRMTAP FROMFILE(QTAPE) FROMDEV(TAP01) TOFILE(ICHDTAP) +
FROMLABEL(ICHDTAP) MBROPT(*REPLACE)
RSTICHDTA LIB(PRODUCTION)
The *ALL option on the SAVICHDTA command copies all members of a
file. It is the default entry. It is normally used for data files,
but can also be used for source files such as:
SAVICHDTA LIB(PRODUCTION) LIST((*CMD *ALL))
The member parameter also supports a generic name so you may specify:
SAVICHDTA LIB(PRODUCTION) LIST((*CMD PAY*)(*CLP PAY*) +
(*RPG PAY*)(*PF PAYMST))
Differences from CPYF
---------------------
The SAVICHDTA command differs from CPYF by the following major items:
** CPYF works with a single file at a time. If a unique member
name is specified, CPYF works only with a single member.
** CPYF does not handle record sizes beyond the TOFILE size.
Only truncation is supported.
** CPYF does not make a separator record for a new member. You
can add records to a file with CPYF, but there is no unique
record output to act as a separator.
Separator record
----------------
The SAVICHDTA command extracts the source records and writes them to
the ICHDTAP file with a standard separator. The separator has the
following format:
1 - 10 File
11 - 20 Library
21 - 30 Member
31 - 40 Source type
41 - 50 Number of records
52 - 57 Member change date
59 - 64 Member change time
66 - 70 Record length
72 - 121 Member text
127 - 128 **
Unused positions are blank.
The FILE and MEMBER values are used to access the file/member in the
library named on the RSTICHDTA command. The same file name used on
the SAVICHDTA must also exist for the restore, but the library may
differ.
If the member does not exist, it is added. The source type and
member text extracted by the SAVICHDTA command are used when a new
member is added. If the member exists, the data is replaced (i.e.
cleared first).
An option exists on the commands to add or remove the special '38'
values and convert certain types (e.g. CLP38 is changed to CL).
Note that the library name in the separator record exists only for
documentation and is not used during the restore. The library name
on the RSTICHDTA command is used. The other fields in the separator
record are used only for documentation.
The record length of the file saved with SAVICHDTA must be the same
as the file to be written to or the RSTICHDTA command will fail.
The codes placed in position 127-128 of each record are as follows:
** Separator record as described previously
*0 A complete data record (i.e. it fits completely in
125 bytes available with or without padding)
01 The first record of a group of records that require
more than one 125 byte segment
02-29 The Nth records in a group
*E The last record in a group
If a record length of 400 bytes is used, there would be an 01, 02, 03
and and *E record for each record in the file. There would be 375
bytes of data in the first three records. The *E record would
contain the remaining bytes for the record which in this case would
be the last 25 bytes plus 100 blanks.
Restrictions
------------
Only physical files can be saved. The files saved on a single
command must all be in the same library, but may be of differing
lengths. If the file has no members, it cannot be saved.
The maximum record size which can be saved for source files is 125
and for data files is 4500 bytes in length.
Considerations
--------------
It is valid to save a file that has no records in the member. The
separator record will be immediately followed by another separator
record.
SAVICHDTA command parameters *CMD
----------------------------
LIB The library which contains the files. For a given
command, all files must come from the same library.
On the RSTICHDTA command, all files must be restored
to a single library, but it may differ from the save
library.
LIST The list of file/members to be saved. This is a
list of up to 50 entries. Each entry is made up of
two elements:
FILE The file containing the member. The file must
be in the library named on the LIB parameter.
The special entries of *CL, *CLP, *RPG etc.
can be used to designate the standard source
file names.
MBR The member name to be saved. The default is
*ALL meaning to save all members in the file.
A generic value may also be entered such as
PAY* to save all the members beginning with
PAY. *FIRST is also valid to save the first
member.
ICHDTAPLIB The library containing the ICHDTAP file. The
default is *LIBL. Note that the default may cause
the file to be in a different library than the files
being saved.
TOMBR The member name of the ICHDTAP file. The default is
*FIRST.
MBROPT Controls if the TOMBR (in the ICHDTAP file) is
cleared before writing records to it. The default
is *REPLACE meaning to clear the member. *ADD may
be specified to add to the records already in the
file.
RMV38 A *YES/*NO option which defaults to *NO. *YES means
to strip off the 38 in the source type (e.g. CLP38
becomes CLP). This allows an i5 System to send S/38
type source to a S/38 and have the correct source
type restored.
Note that if you specify a generic or *ALL value for the member and a
special type like *PF such as:
SAVICHDTA LIB(PRODUCTION) LIST((*PF *ALL))
The *PF entry is a shorthand for QDDSSRC. You would save all of the
source members in QDDSSRC and not just the *PF types.
For the SAVICHDTA command, if 1) a file/member cannot be found or 2)
no members exist for a generic group, a diagnostic is sent for each
error and the command will complete with an escape message. Any
members which are valid will be saved.
If 1) the file does not exist or 2) the file has no members or 3) the
file is not a physical file, the command will fail with an
appropriate escape message. This may occur after some members have
been saved.
If the command completes normally, a completion message describes the
number of members successfully copied.
RSTICHDTA command parameters *CMD
----------------------------
LIB The library which contains the files to be written
to. This may differ from the library used on the
SAVICHDTA command. All files must be written to the
same library.
ICHDTAPLIB The library containing the ICHDTAP file. The
default is *LIBL.
FROMMBR The member name of the ICHDTAP file. The default is
*FIRST.
ADD38 A *YES/*NO option which defaults to *NO. *YES means
to add '38' to the source type (e.g. CLP becomes
CLP38). This allows S/38s to send source to an i5
System and have the correct source type.
The RSTICHDTA command ensures that the group records (i.e. caused by
records exceeding 125 bytes in length) are in sequence.
Any errors on the RSTICHDTA command cause the command to fail
immediately. This may result in some of the members being copied and
some not.
If errors occur (e.g. no file exists), you can correct the problem
and reissue the command. There is no method of starting in the
middle of the ICHDTAP file, but this could be done using an OVRDBF
command and the POSITION parameter to describe the relative record
number start position.
If the command completes normally, a completion message exists
describing the number of members copied.
Restoring to an S/38
--------------------
To assist you in using the S/38 version, a CLP38 type source is
provided. You should do the following steps to create the RSTICHDTA
function on an S/38.
1. The command definition source for RSTICHDTA (TAASAVD2 in
QATTCMD) should be copied in data interchange mode (e.g. to
diskette or tape) and placed on the S/38. Use CRTCMD to
create RSTICHDTA using the TAASAVD2 command definition source
and specify PGM(TAASAVDC3).
2. The CPP for RSTICHDTA (TAASAVDC3 in QATTCL) should be copied
in data interchange mode and placed on the S/38. There are
two commands which exist in the source (ADDSRCMBR and EDTVAR)
that are used in the CL program. These commands are part of
the S/38 Tips and Techniques TIPSTECH library. If this is not
available to you, there are instructions in the program for
how to bypass the functions provided. See the source for
TAASAVDC3. Use CRTCLPGM to create TAASAVDC3.
3. The RPG source (TAASAVDR2 in QATTRPG) should be copied in data
interchange mode and placed on the S/38. Use CRTRPGPGM to
create TAASAVDR2.
Once the objects are created, you can use the RSTICHDTA command on
S/38 to transfer source from an i5 System to the S/38.
Prerequisites
-------------
The following TAA Tools must be on your system:
CHKDBF Check data base file
CHKGENERC Check generic
EDTVAR Edit variable
RTVGENMBR Retrieve generic member
SNDCOMPMSG Send completion message
SNDDIAGMSG Send diagnostic message
SNDESCMSG Send escape message
SNDSTSMSG Send status message
Implementation
--------------
The tool is ready to use, but you must create the data base file to
save into such as:
CRTPF FILE(ICHDTAP)
RCDLEN(128)
SIZE(50000 10000 5)
TEXT('File used by SAV/RSTICHDTA')
Objects used by the tool
------------------------
Object Type Attribute Src member Src file
------ ----- --------- ---------- -----------
SAVICHDTA *CMD TAASAVD QATTCMD
RSTICHDTA *CMD TAASAVD2 QATTCMD
TAASAVDC *PGM CLP TAASAVDC QATTCL
TAASAVDC2 *PGM CLP TAASAVDC2 QATTCL
* No object TAASAVDC3 QATTCL
TAASAVDR *PGM RPG TAASAVDR QATTRPG
TAASAVDR2 *PGM RPG TAASAVDR2 QATTRPG
** ICHDTAP *FILE PF No source
* The TAASAVDC3 source is for the S/38 version. See the prior
discussion.
** The ICHDTAP file must be created using the CRTPF command described
previously.
Structure
---------
SAVICHDTA
TAASAVDC CL pgm
TAASAVDR RPG pgm
ICHDTAP physical
RSTICHDTA
TAASAVDC2 CL pgm
TAASAVDR2 RPG pgm
ICHDTAP physical
See the previous discussion for using RSTICHDTA on S/38 concerning
the TAASAVDC3 CLP38 program.
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