The RUNCHAIN EXEC

Syntax

RUNCHAIN <addr> link(<offset>,<s>) stopvalue(<stop>) chain(<nnn>) exec(<cmd>)
         print(<file>)

This exec provides a generalised control block chaining facility, where at each hop of the chain a command or exec may be executed. The starting address and link offset are required. Other parameters are optional. The parameters to RUNCHAIN are:

<addr>

is an address expression of the start of the chain
<offset>
specifies the decimal or hexadecimal offset of the linking address. Default is 0
<s>
specifies the length of the linking field as: D (double) or W (word) - Default is D
<stop>
specifies a termination value for the linking field. This take precedence over <chain> and may be specified as a hexadecimal or decimal value.
<nnn>
specifies the maximum number of chain hops to traverse. Default is 10
<cmd>
specified a command to be executed at each hop. If the command is prefixed with a % then an exec is executed. @L will cause the linear address of the current block to be substituted. Default is DD @L L4.
<file>
specifies a print file to which the output will be copied.

Note:

Hexadecimal values are specified as 'nn'x

As an example: suppose the linear address of an MTE is %fff2bde0. MTEs are linked at +c in os2 2.1. To run the chain of MTEs displaying 8 double words do the following:

%RUNCHAIN %fff2bde0 link(c) exec(DB @L L40)

The resulting output would be appear thus:

Block 1 at %FFF2BDE0

%fff2bde0  00060002 fff2bdfc fff2bfc3 fe0a1dac
%fff2bdf0  0000b980 00000000 00010000 00000000

Block 2 at %fe0a1dac

%fe0a1dac  02600002 fcace908 fe0a1dfc fe083e40
%fe0a1dbc  4498b1c6 0000000d 0000003a fe0addf0

Block 3 at %fe083e40

%fe083e40  024e0002 fcac52f0 fe083e70 fe0adef8
%fe083e50  4498b1c6 00000005 00000038 fdf40fac

Block 4 at %fe0adef8

%fe0adef8  01aa0002 fcac07a0 fe0adf14 fdf61cc8
%fe0adf08  0498b1c8 00000000 00000035 4d495405

Block 5 at %fdf61cc8

%fdf61cc8  01a80002 fca9ad58 fdf61ce4 fdf61d68
%fdf61cd8  0498b1c8 00000000 00000036 53595307
Chain run successfully for 5 hops

To format the first 40 MTEs in the chain do:

%RUNCHAIN %fff2bde0 link(c) exec(.lmo @L) chain(40)

---

[Back: PMDF REXX interface]
[Next: The PS EXEC]