/sys$common/syshlp/helplib.hlb Lexicals, F$CONTEXT, Examples  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    1.$!Establish an error and Ctrl/Y handler
      $!
      $ ON ERROR THEN GOTO error
      $ ON CONTROL_Y THEN GOTO error
      $!
      $ ctx = ""
      $ temp = F$CONTEXT ("PROCESS", ctx, "NODENAME", "*","EQL")
      $ temp = F$CONTEXT ("PROCESS", ctx, "USERNAME", "M*,SYSTEM","EQL")
      $ temp = F$CONTEXT ("PROCESS", ctx, "CURPRIV", "SYSPRV,OPER", "ALL")

      $!
      $!Loop over all processes that meet the selection criteria.
      $!Print the PID and the name of the image for each process.
      $!
      $loop:
      $ pid = F$PID(ctx)
      $ IF pid .EQS. ""
      $ THEN
      $     GOTO endloop
      $ ELSE
      $     image = F$GETJPI(pid,"IMAGNAME")
      $     SHOW SYMBOL pid
      $     WRITE SYS$OUTPUT image
      $     GOTO loop
      $ ENDIF
      $!The loop over the processes has ended.
      $!
      $endloop:
      $!
      $ EXIT
      $!
      $!Error handler. Clean up the context's memory with
      $!the CANCEL selection item keyword.
      $!
      $error:
      $ IF F$TYPE(ctx) .eqs. "PROCESS_CONTEXT" THEN -
      _$ temp = F$CONTEXT ("PROCESS", ctx, "CANCEL")
      $!
      $ EXIT

      In this example, F$CONTEXT is called three times to set up
      selection criteria. The first call requests that the search
      take place on all nodes in the cluster. The second call
      requests that only the processes whose user name either
      starts with an "M" or is "SYSTEM" be processed. The third
      call restricts the selection to those processes whose current
      privileges include both SYSPRV (system privilege) and OPER
      (operator) and can have other privileges set.

      The command lines between the labels "loop" and "endloop"
      continually call F$PID to obtain the processes that meet the
      criteria set up in the F$CONTEXT calls. After retrieving each
      PID, F$GETJPI is called to return the name of the image running
      in the process. Finally, the procedure displays the name of the
      image.

      In case of error or a Ctrl/Y operation, control is passed to
      error and the context is closed if necessary. In this example,
      note the check for the symbol type PROCESS_CONTEXT. If the
      symbol has this type, selection criteria must be canceled by
      a call to F$CONTEXT. If the symbol is not of the type PROCESS_
      CONTEXT, either selection criteria have not been set up yet
      in F$CONTEXT, or the symbol was used with F$PID until an error
      occurred or until the end of the process list was reached.

    2.f$context("process",ctx,"prcnam  ","symbiont*,mcote*","eql")

      f$context("process",ctx,"prcnam  ","symbiont*,mcote* ","neq")

      f$context("process",ctx,"prcnam  ","mcote* ","neq")
      f$context("process",ctx,"prcnam  ","symbiont*","neq")

      This example shows three sets of lexicals showing the
      difference between the EQL and the NEQ selection values. The
      first lexical function (with EQL) passes back all processes
      with symbiont and mcote in the process name. The second and
      third lexical functions (with NEQ) are equivalent in that they
      both will pass back all processes (processes that do not have
      symbiont in the process name, or processes that do not have
      mcote in the process name.)