Dropping a Buffer with the DROPBUF Command

When an exec has no more need for a buffer on the data stack, it can use the TSO/E REXX DROPBUF command to remove the buffer (and its contents). The DROPBUF command removes the most recently created buffer.

To drop a specific buffer on the data stack and all buffers created after it, issue the DROPBUF command with the number of the buffer. The first MAKEBUF creates buffer 1, the second creates buffer 2, and so on. For example, if an exec issued three MAKEBUF commands that created three buffers, when you issue DROPBUF 2, the second and third buffers and all elements within them are removed.

To remove all elements from the entire data stack including elements placed on the data stack before buffers were added, issue DROPBUF 0. DROPBUF 0 creates an empty data stack and should be used with caution.

Note: When an element is removed below a buffer, the buffer disappears. Thus when elements are unintentionally removed below a buffer, the corresponding DROPBUF command might remove the incorrect buffer and its elements. To prevent an exec from removing elements below a buffer, use the QUEUED built-in function or use the NEWSTACK command as described in Protecting Elements in the Data Stack.