Appendix E: File-Stack Processing

A file stack is multiple sets of fixed-length, logical records, stored in a single, physical scratch file. These logical record sets are organized in the file in a last-in, first-out (LIFO) stack manner. A file stack enables you to “stack” temporary files, rather than maintaining multiple files individually.

File stacks are maintained by the Toolkit file-stack subroutines. These routines are used by Toolkit’s list processor, and can be called from your applications as well.

Introduction to file-stack processing

The file-stack subroutines

FS_APPEND - Append a record to the current logical file

FS_CLOSE - Close one or more logical files

FS_INIT - Initialize a file-stack system

FS_OPEN - Add a logical file to the top of the stack

FS_PARAM - Get a logical file’s parameters

FS_QUIT - Terminate a file-stack system

FS_READ - Read an existing record from a logical file

FS_WRITE - Write a record to a logical file