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| Chapter 2 UNIX Commands |

## ismpx

    ismpx [option]

Test whether standard input is running under layers. (Command name comes from "Is the multiplexor running?") Output is either yes (exit status 0) or no (exit status 1). Useful for shell scripts that send programs to a windowing terminal or depend on screen size.

### Option

-s

  Suppress output and return exit status only.

### Example shell script

>     if ismpx -s
>     then jwin
>     fi

Reference: ipcs |  | Reference: join