Pascal application programming

Application programs in Pascal use the following format, parameters, and DL/I calls to communicate with IMS™ databases.

Format


>>-+-PASTDLI--(--| A |--+-------------------------+-+--);------><
   |                    +-,VAR--db pcb--| B |-----+ |       
   |                    +-,VAR--tp pcb--+-------+-+ |       
   |                    |               +-| B |-+ | |       
   |                    |               '-| C |-' | |       
   |                    '-| D |-------------------' |       
   '-AIBTDLI--(--| A |--,--VAR--aib,--+-------+-----'       
                                      +-| B |-+             
                                      '-| C |-'             

A

|--+---------------------+--CONST--function---------------------|
   '-CONST--parmcount--,-'                    

B

|--,VAR i/o area--+----------------------+----------------------|
                  | .-,--------.         |   
                  | V          |         |   
                  +---,VAR ssa-+---------+   
                  +-,CONST token---------+   
                  +-,CONST stat function-+   
                  +-,VAR rsa-------------+   
                  '-,VAR rootssa---------'   

C

|--,VAR i/o area length,--VAR i/o area--+-------------------------------+--|
                                        | .-,-------------------------. |   
                                        | V                           | |   
                                        '---,VAR area length,VAR area-+-'   

D

|--,VAR psb name,--VAR uibptr--+---------------+----------------|
                               '-,VAR sysserve-'

Parameters

parmcount: Specifies the name of a fixed binary (31) variable in user-defined storage that contains the number of parameters in the parameter list that follows parmcount.
function: Specifies the name of a character (4) variable, left justified in user-defined storage, that contains the call function to be used. The call function must be left-justified and padded with blanks (such as GUbb).
db pcb: Specifies the name of a pointer variable that contains the address of the database PCB defined in the call procedure statement.
tp pcb: Specifies the name of a pointer variable that contains the address of the I/O PCB or alternate PCB defined in the call procedure statement.
aib: Specifies the name of the pointer variable that contains the address of the structure that defines the application interface block (AIB) in user-defined storage.
i/o area: Specifies the name of a pointer variable to a major structure, array, or character string that defines the I/O area in user-defined storage used for the call. The I/O area must be large enough to contain all of the returned data.
i/o area length: Specifies the name of a fixed binary (31) variable in user-defined storage that contains the I/O area length.
area length: Specifies the name of a fixed binary (31) variable in user-defined storage that contains the length of the area immediately following it in the parameter list. Up to seven area lengths or area pairs can be specified.
area: Specifies the name of the pointer variable that contains the address of the structure that defines the user-defined storage to be checkpointed. Up to seven area lengths or area pairs can be specified.
token: Specifies the name of a character (4) variable in user-defined storage that contains a user token.
stat function: Specifies the name of a character (9) variable in user-defined storage that contains the stat function to be performed.
ssa: Specifies the name of a character variable in user-defined storage that contains the SSAs to be used for the call. Up to 15 SSAs can be specified, one of which is rootssa.
rootssa: Specifies the name of a character variable that defines the root segment search argument in user-defined storage.
rsa: Specifies the name of a character variable that contains the record search argument.
psb name: Specifies the name of a character (8) variable containing the PSB name to be used for the call.
uibptr: Specifies the name of a pointer variable that contains the address of the structure that defines the user interface block (UIB) that is used in user-defined storage.
sysserve: Specifies the name of a character (8) variable string in user-defined storage to be used for the call.

Example of a DL/I call format

Using the DL/I AIBTDLI interface:

AIBTDLI(CONST function,
  VAR aib,
  VAR i/o area,
  VAR ssa1);

Using the DL/I language-specific interface:

PASTDLI(CONST function,
  VAR db pcb,
  VAR i/o area,
  VAR ssa1);