tests whether there is an expression ready to read from the specified WSTP connection.


waits for up to t seconds to see if an expression becomes ready to read.


tests all the linki in parallel, returning as soon as any of them are ready to read from.


  • The linki must be active LinkObject objects, as returned by functions like LinkLaunch or Links.
  • LinkReadyQ[{link1,link2,},t] returns a list of True and False, specifying which of the linki are ready to read from.
  • If LinkReadyQ[link] returns True, then LinkRead[link] will not block under any normal circumstances.
  • If LinkReadyQ[link] returns False, then LinkRead[link] will block, and will not return until something becomes available to read on link.
  • LinkReadyQ[link] tests whether there is any data to read; it cannot determine whether the data represents a complete expression.
  • The basic form of LinkReadyQ corresponds to the WSTP library function WSReady().


Basic Examples  (1)

Launch a subsidiary Wolfram Language kernel process:

LinkReadyQ will now report an expression waiting to be read:

Read the expression:

Now the link will be empty:

Close the link:

Introduced in 1996
Updated in 2007