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The scope of a channel

The scope of a channel is the code from which it can be accessed.

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Scope example, with LINK commands

The following figure shows the same five interactive programs previously described in "Current channel example, with LINK commands".

The scope of the X channel--the code from which it can be accessed--is programs A, B, and C.

The scope of the Y channel is programs D and E.

Note that, by the time control is returned to program A by program B, the X channel has been modified--it doesn't contain the same set of containers as when it was created by program A.

Figure 49. The scope of a channel--example showing LINK commands
The picture shows the scenario described in the text.

The following table lists the name and scope of the current channel (if any) of each of the five programs shown in the previous figure.

Table 11. The scope of a channel--example with LINK commands
Program Current channel Scope of channel
A None Not applicable
B X A, B, C
C X A, B, C
D None Not applicable
E Y D, E
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Scope example, with LINK and XCTL commands

Figure 50 shows the same four interactive programs previously described in "Current channel example, with XCTL commands", plus a third-level program, C1, that is invoked by an EXEC CICS LINK command from program B1.

The scope of the X channel is restricted to A1 and B1.

The scope of the Y channel is B2 and B3.

The scope of the Z channel is B1 and C1.

Note that, by the time control is returned to program A1 by program B3, it's possible that the X channel may have been modified by program B1--it might not contain the same set of containers as when it was created by A1.

Figure 50. The scope of a channel--example showing LINK and XCTL commands
The picture shows the scenario described in the text.

The following table lists the name and scope of the current channel (if any) of each of the five programs shown in Figure 50.

Table 12. The scope of a channel--example with LINK and XCTL commands
Program Current channel Scope of channel
A1 None Not applicable
B1 X A1 and B1
B2 None Not applicable
B3 Y B2 and B3
C1 Z B1 and C1
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