Invoking ISPF services with program functions

Programs call ISPF services by invoking an ISPF subroutine interface. The two basic call interfaces are ISPEXEC and ISPLINK. However, FORTRAN and Pascal use the alternate name forms ISPEX and ISPLNK, because these languages limit a module name to 6 characters. A program cannot use an ISPLINK call to invoke APL2®.

Call statements in this document are shown in PL/I syntax. Service names and keyword values are shown as literals, enclosed in single quotes ('); for example:

CALL  ISPLINK ('TBOPEN  ', 'XTABLE ', 'NOWRITE ');

or, alternatively:

 ...set BUFLEN equal to 21...
CALL  ISPEXEC (BUFLEN, 'TBOPEN XTABLE NOWRITE');

Some languages, such as COBOL, do not allow literals within a call statement. Use of literals is never required for any language. All parameters can be specified as variables.