Snap Target Data Sets

Introduction

The SNAP function of the IOF Job Summary and Browse Panels causes sysout data records to be copied to an external (target) data set. You can specify a target SNAP data set by entering an SS or SD command before requesting any SNAP operations, or you can take the default target.

Default SNAP Target Data Set

If a SNAP function is requested and no target data set has been specified, the default target data set will be a spun sysout data set with your default class and print destination. See Chapter 6 for instructions on setting your default class and print destination on the IOF User Profile Options panel.

If you want to change any of the attributes of the spun sysout data set, or if you want to snap data to a tape or disk data set, enter an SS or SD command before requesting any SNAP operations.

Closing or Changing the SNAP Target Data Set

The SNAP target can be explicitly closed by the SNAPCLOS command or by another SS or SD command. It also will be implicitly closed under the following conditions:

  • If the SS or SD command was entered in the Job List Menu, Output Group Display, or System Monitor the target data set is implicitly closed when the IOF session is terminated. Output from several jobs can be snapped to the same target data set.
  • The default target data set, and target data sets defined by an SS or SD command on the Job Summary or Browse panels are implicitly closed when the Job Summary for the job is terminated. Output from several sysout data sets of a job can be snapped to the same target data set.

    Specifying a Spun Sysout Target Data Set (SS)

    The SS command is used to explicitly specify a sysout target data set. If you know that you want to snap to a sysout target data set but are unsure about the attributes (destination, class, etc.), enter the SS command with no operands. This will display the Snap to Sysout Data Set interface panel that will help you set up the right attributes for your target sysout data set. 

    
-------------------Snap-to-Sysout-Data-Set-----(Screen-1-of-5)-----------------
 COMMAND ===>

          Blank - Open SNAP data set and return
          Down  - Display panel with more SNAP attributes

 CLASS        ===>                     Sysout class
 DEST         ===>

 OUTDISP      ===>                     Output disposition (WRITE/KEEP/HOLD)
 CC           ===> A                   Carriage control: A, M, or NONE
 OPTCD        ===>                     "J" for 3800 printers
 PAGEDEF      ===>            FORMDEF ===>            FORMS ===>

 TITLE        ===>

 NAME         ===>
 ROOM         ===>
 BUILDING ===>
 DEPT         ===>
 ADDRESS      ===>
              ===>
              ===>
              ===>

    Note that the most common sysout data set attributes are displayed on the first panel, but that you can scroll down to display additional sysout attributes. 

    
-------------------Snap-to-Sysout-Data-Set-----(Screen-2-of-5)-----------------
 COMMAND ===>

          Blank - Open SNAP data set and return
          Down  - Display panel with more SNAP attributes
          Up    - Display panel with more SNAP attributes

 OUTNAME ===>                       Pre-allocated OUTPUT statement name

 COPIES      ===>                   UCS     ===>             FCB     ===>

 NOTIFY      ===>                   INDEX   ===>             LINDEX  ===>
             ===>                   CKPTPGS ===>             CKPTLNS ===>
             ===>                   BURST   ===>             PRMODE  ===>
             ===>                   FLASHC  ===>             Z       ===>

 PRTY        ===>                   OUTBIN  ===>             COMSET  ===>
 WTRID       ===>                   LINECT  ===>             FLASH   ===>
 MODTRC      ===>                   CHARS   ===>
 MODIFY      ===>                   COPYG   ===>

    The interface panels can be bypassed if you know the specific sysout attributes you want. This is the easiest way to specify sysout characteristics when running from a clist. To specify sysout target data set attributes, enter the SS command followed by the attributes. For example: 

    SS COPIES(4) DEST(LOCAL) CLASS(X)

    See Chapter 15 for a complete description of all valid sysout attributes.

    Specifying an MVS Target Data Set

    The SD command is used to explicitly specify a non-vsam MVS target data set for SNAP. This includes MVS disk and tape output data sets. If the SD command is entered with no parameters, the IOF Snap Data Set Options interface panel is displayed to assist in allocating the target data set. 

    
----------------------------IOF-Snap-Data-Set-Options--------------------------
 COMMAND ===>

       DSNAME        ===> ASCHINT.IOFLIST

       RECFM         ===> VBA           Record format
       LRECL         ===> 255           Logical record length
       BLKSIZE       ===> 3600          Block size
       PRIMARY       ===> 20            Primary allocation   (in tracks)
       SECONDARY     ===> 20            Secondary allocation (in tracks)

       UNIT          ===>               Unit name
       VOLUME SER.   ===>               Volume serial
       STORCLAS      ===>               SMS storage class
       MGMTCLAS      ===>               SMS management class
       DATACLAS      ===>               SMS data class

       MOD (Y or N)  ===>               Append data to end of existing data set
       PACK(Y or N)  ===>               Pack data using ISPF method

       LABEL         ===>               Tape data set label type
       DATASET NO.   ===>               Tape data set sequence number

    Note that the default data set name is jobname.IOFLIST. You can change the default name by selecting the P option and then selecting option 5. The data set name, including a fully qualified name enclosed in single quotes, can be specified by overtyping. You can also specify a member of a partitioned data set by including the member name in parenthesis with the data set name.

    The specified (or defaulted) data set will automatically be created if it does not already exist. See Record Structure for MVS Target Data Sets below for a discussion of default DCB attributes and how to change them.

    All the displayed data set attributes can be overtyped on the panel. The default values can be set on option P.5. To append SNAP data to the end of an existing data set, specify YES in the MOD field. IOF will not specify LRECL, BLKSIZE, or RECFM if Y is specified for MOD. This means that specifying MOD for a data set that has never been written into can cause unpredictable results.

    Note that your userid must be granted mount authority before you can SNAP to a tape data set.

    Specifying a Client Target Snap Data Set

    When running on an IOF server, the SC command is used to define a target snap data set on the client. To define a sysout target snap data set on the client, enter SC followed by an SS command. To define a MVS target snap data set, enter SC followed by an SD command. Either SS or SD must be specified on the command.

    Examples:

                 SC SS CLASS (A)
             SC SD DA (MYTARGET)

    Record Structure for MVS Target Data Sets

    The default record format for disk and tape target data sets is an installation parameter. It is displayed when you enter the SD commands with no parms. You can override these defaults on the IOF Snap Data Set Options panel, or with the RECFM, LRECL, and BLKSIZE operands of the SD command. Specifying an LRECL value shorter than the maximum record length being snapped will cause truncation of records which are longer than the LRECL value.

    The panel and the SD command support all valid combinations of the RECFM characters V, F, B, U, A, and M. Note that you can specify either ASA or machine print control characters. If you specify a different type of print control character from the original data being snapped, then IOF automatically converts the snapped output to the specified type.

    The IOF Snap Data Set Options interface panel can be bypassed if you know the specific data set attributes you want. This is the easiest way to specify data set attributes when running from a clist. Enter the SD command followed by the desired attributes: 

    Parameter                               Description
DSNAME(data.set.name)                   data set name
TRACKS(prim      sec)                   primary and secondary space
RECFM(fmt)                              record format
LRECL(len)                              logical record length
BLKSIZE(len)                            block size
VOLUME(volser)                          tape or disk volser
UNIT(unittype)                          unit type
MSVGP(mss-unittype)                     MSS unit type
MOD                                     add to an existing data set
LABEL(NL/SL/NSL/SUL/BLP,LTM/AL/AUL) tape label type
DISP(WRITE/HOLD/KEEP/LEAVE)             output data set disposition
POS(n)                                  tape file number
STORCLAS(class)                         storage class
MGMTCLAS(class)                         management class
DATACLAS(class)                         data class
SUBTASK(YES/NO)                         do I/O on subtask
DCB(YES/NO)                             use existing DCB parms
PACK                                    save in ISPF packed format

    Snap Headers

    It is often useful to add header information to snap target data sets for identification and separation of data. The SNAPTEXT command can be used to add header information to both sysout and disk snap data sets. SNAPTEXT is particularly useful when used from IOF REXX execs and clists.

    Syntax

    SNAPTEXT [ BUILD ]

    [ ASA(asa-ctl) / MACHINE(mac-ctl) ]

    [ CHAR line-of-text / HEX hex-data ]

    BUILD. Specifies that a complex header record is being built. The carriage control or data is added to the record but output is not yet written. A SNAPTEXT command with no parms is used to write a header record previously constructed with SNAPTEXT BUILD commands.

    asa-ctl. The optional ASA carriage control character.

    mac-ctl. The optional machine carriage control character in hexadecimal.

    CHAR. Specifies that character header data follows.

    line-of-text. The string of character data to be added to the snap target data set.

    HEX. Specifies that hexadecimal header data follows.

    hex-data. The string of hexadecimal data to be added to the snap target data set.

    Examples 

             SNAPTEXT ASA(1) CHAR Example header at top of form
         SNAPTEXT MACHINE(8B) CHAR Machine control example header
         SNAPTEXT CHAR This data will be printed on the next line
         SNAPTEXT BUILD ASA(1)
         SNAPTEXT BUILD HEX 7B3EF2
         SNAPTEXT BUILD CHAR Character part of a complex header
         SNAPTEXT

    Note that SNAPTEXT with no parms causes the accumulated data record to be written.

    Block Headers

    It may be useful to add block headers to snap target data sets. Block headers are particularly useful for defining data separators when preparing output for microfilm or CD rom.

    The SNAPHDR command utilizes SNAPTEXT to produce block headers in the snap target data set. Three block header formats are supported, and it is relatively easy to add additional local formats.

    Syntax

    SNAPHDR [ 1 / 2 / 3 ] [SLANT] header-text

    1/2/3 Optionally specifies the block header format.

    1 Specifies the default block header format of 7 lines by 5 characters wide.

    2 Specifies a block header 7 lines by 7 characters wide.

    3 Specifies a block header 13 lines by a proportional width.

    SLANT. If specified, causes the block letters to be slanted.

    header-text. The text to be blocked. Note that the number of characters that can be written to the output line is a function of the header format and the line width. The header text will be truncated when it will not fit on the snap target output line. Lower case characters are exploded to upper case.

    Examples 

                SNAPHDR 1 FRIDAY 21 FEB1997
            SNAPHDR 2 SLANT SALARIED PAYROLL
            SNAPHDR 3 JANUARY

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