WSActivate (C Function)

int WSActivate(WSLINK link)

activates a WSTP connection, waiting for the program at the other end to respond.


  • WSActivate() can be called only after one of the WSOpen functions such as WSOpenArgcArgv() or WSOpenString().
  • Any call that reads data from or writes data to a link will activate the link automatically if WSActivate() has not been called.
  • WSActivate() returns 0 in the event of an error, and a nonzero value if the function succeeds.
  • WSActivate() on an already activated link will do nothing.
  • If the other side of the link has not yet been created, then the behavior depends upon whether the link was created using "-linkconnect". If the link was created, then WSActivate() will wait for the link to be both connected and activated. If the link is a connecting link, then WSActivate() will immediately return an error and close the link.
  • If WSActivate() blocks, it will call the yield function set by WSSetYieldFunction().
  • When called on an inactive link, WSReady() can be used to determine whether the other side of the link has been created.
  • Use WSError() to retrieve the error code if WSActivate() fails.
  • WSActivate() is declared in the WSTP header file wstp.h.


Basic Examples  (1)

#include "wstp.h"

/* create a link and establish the connection */

int main(int argc, char **argv)
    WSENV env;
    WSLINK link;
    int error;

    env = WSInitialize((char *)0);
if(env == (WSENV)0)
{ /* unable to initialize the WSTP environment */ }

    /* let WSOpenArgcArgv process the command line */
    link = WSOpenArgcArgv(env, argc, argv, &error);
    if(link == (WSLINK)0 || error != WSEOK)
{ /* unable to create the link */ }

    /* WSActivate will establish the connection */
{ /* unable to establish communication */ }

    /* ... */


    return 0;