How to Run Tcl from ESL Script

How to Inter-Work with Tcl from ESL Script

Objectives

In this tutorial you'll learn HOW TO:
► Incorporate and call Tcl scripts from your ESL test
► Mix ESL and inline Tcl commands in the same ESL script
► Load and inter-work with the pure Tcl script lacated in an external file
► Inject input parameters to Tcl
► Receive result values returned by your Tcl routines

All Tutorials

How to ...

Write a Script

Copy the script below to your ESL and run to explore how to inter-work with Tcl.
The script performs the following:
► Create Tcl object which is mandatory step.
► Define an inline Tcl routine to call it further on.
► Use TCL_Eval command to perform Tcl commands inline with ESL script.
► Receive results from Tcl script using output parameter Status containing the Tcl return value
► Open Windows file explorer using the ESL command InputOpenFileName to load your Tcl script file.
► Run your loaded Tcl with TCL_EvalFile ESL command.
► Make sure that your script releases all Tcl resources at the end, and deletes Tcl object with ESL TCL_Delete command.

     Declare Status , TCL

     ; Create Tcl Interpreter object
     TCL_Create TCL , "C:\Tcl\bin\tcl85.dll" , 1

     ; Define a new inline Tcl funtion MyReturn2
     TCL_AddCode TCL
        proc MyReturn2 {arg1} {
             if { $arg1 < 100 } {
                 return "a"
             } else {
                 return "b"
             }
         }
     TCL_EndCode

     TCL_Eval Status , TCL , "set a 12" ; Status contains 12 (equivalent to Status=12)
     TCL_Eval Status , TCL , "set a 12^Jset b 16" ; Status is 16
     TCL_Eval Status , TCL , "set a 12^Jputs $a"    ; STatus  is 12
     ; Ccll MyReturn2 with parameter 21, Status will return 12
     TCL_Eval Status , TCL , `puts " MyReturn2 of 21 is: [MyReturn2 21]"`
     ; Ccll MyReturn2 with parameter 221, Status will return 16
     TCL_Eval Status , TCL , `puts " MyReturn2 of 221 is: [MyReturn2 221]"`
     ; Ccll MyReturn2 with parameter 300, Status will return 16
     TCL_Eval Status , TCL , `MyReturn2 300`

     ; Open Windows file explorer to load your Tcl script from a file.
     Declare FileName
     InputOpenFileName Status , FileName
     if Status != 0 Then
         ; Execute the loaded Tcl script as is.
         TCL_EvalFile Status , TCL , FileName
         TMMessage GT_InfoID , 'Result = ' $ Status
     EndIf

     ; You must delete the TCL object at the end.
     TCL_Delete TCL

;   Let _RetStat = 0
;   Let _RetVal  = 0
     End ;@DBG:NEST - 1 - @DBG:IsInJob; Exit Current Test

Use ESL command ChDir to change the Windows current path.
This is required when your TCL opens some file (like SVC, etc.) without referring the full path.
For example:

ChDir Status , "c:\myTcl\MyProject"
TCL_EvalFile Status , TCL , "C:\myTcl\MyProject\MyTcl.tcl "

Resources

To do your hands-on practice more effective:

Watch the "How to Automate Windows Command Line Operations" tutorial.

Watch the "How to Write Data Driven Test" tutorial.

Install the ETS Free Edition on your PC.

Download the "Get Started" project with all up-to-date tutorial scripts. Unzip it to C:\ETS_Workspaces.