==== STKPUSH ====
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<callout type="primary" color="" icon="fa fa-book" title="Synopsis">
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Push a snapshot of the current stack on the Undo stack
</callout>

<callout color="green" icon="fa fa-indent" title="Stack Diagram">
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^  __Input Stack__  ^  ^  __Output Stack__  ^
|  |  **→**  |  |
|  //Level 1//  |  //→//  |  //Level 1//  | 

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|**Type**| [[manual:chapter5:basics#commands|Command]]  ||
|**Parallel list processing**| [[manual:chapter5:listproc#group-1commands-that-cannot-parallel-process|Group 1]]  || 
|**Affected by flags**| None  ||
</callout>

<callout color="orangered" icon="fa fa-comment" title="Description">
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The ''STKPUSH'' command creates a snapshot of the stack and pushes it on the top of the Undo stack. The Undo stack may contain up to 8 snapshots: each time a ninth is pushed on it, the snapshot on level 8 is lost.

The command has little utility in interactive mode, since each time a command is typed and ''[[manual:chapter6:operators:cmd_ovr_xeq|XEQ]]''ted a snapshot of the stack is already pushed on the Undo stack: the only effect of ''STKPUSH'' would be to duplicate the latest snapshot.
</callout>

<callout type="danger" icon="true" title="Compatibility">
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This command is new in newRPL and does not exist in userRPL.
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<callout type="info" icon="true" title="Usage">
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The following program
<code>
« 123
  456
  789
  STKPUSH
  CLEAR
»
</code>
leaves an empty stack. If **LF** is pressed, the previous stack will be restored.
<code>
3:                           123
2:                           456
1:                           789
……………………………………………………………………………………
</code>
</callout>

<callout color="darkgray" icon="fa fa-hand-o-right" title="Related Commands">
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