LoadRunner - Date Handling (3 of 3) - Powershell

If you are using LoadRunner, you've probably encountered date and time values in your scripts. These values should be evaluated and dealt with.

 Recap of Part 1 and 2

• Part 1 : lr_save_datetime. Works well for dates relative to the current date.
• Part 2 : C date/time functions. User must handle format codes and locale.

Let's solve the problem using Powershell.

 Initial Thoughts

• lr_save_datetime and C date/time functions can handle all situations.
• Looking for an easier, more robust solution.
• LoadRunner does not natively support Powershell.
• How can I call any Powershell command, not just date/time commands?

Below are 3 different ways to call Powershell commands within LoadRunner.

 Support Code

• Used by all 3 implementations.
• Save Powershell output to a unique file (per virtual user).
• Retrieve Powershell output from the file and save in a LoadRunner parameter.

Generate Unique File Name

int iVuserId;
char strFile[100];

lr_whoami (&iVuserId, NULL, NULL);
if (iVuserId <= 0) { iVuserId = 1; }
sprintf (strFile, "d:\\dt-%03d.txt", iVuserId);

Save Powershell Output To A LoadRunner Parameter

int GetParamValue (char *strFile, char *strParam)
{
    long fs;
    char strLine[128];

    // -------------------------------------------------------------------------
    // Read the updated file that contains the new date.
    // Create a new LoadRunner parameter.
    // -------------------------------------------------------------------------

    fs = fopen (strFile, "r");
    fgets (strLine, 128, fs);
    fclose (fs);

    strLine[strlen(strLine)-1] = 0;
    lr_save_string (strLine, strParam);

    return 0;
}

 Using system

• Executes an operating system command.
• Directly available in LoadRunner.
• Displays a command window while the command is executing.

GetNewDate_system

int GetNewDate_system (char *strDate, char *strFormat, char *strFile,
                       char *strChange, int iChangeAmount, char *strParam)
{
    char strCommand[256];
    sprintf (strCommand, 
             "powershell \"$a=get-date '%s'; $a=$a.%s(%ld); $a=get-date $a -format '%s'; "
             "$a|out-file -encoding ascii -filepath %s;\"", 
             strDate, 
             strChange,
             iChangeAmount, 
             strFormat, 
             strFile);

    system (strCommand);
    GetParamValue (strFile, strParam);
    return 0;
}

 Using ShellExecuteA

• Opens, prints or executes a file using the Windows shell.
• Returns immediately after performing specified action.
• Sleep of 1 second is used to allow processing to complete.

GetNewDate_shellexecute

int GetNewDate_shellexecute (char *strDate, char *strFormat, char *strFile,
                             char *strChange, int iChangeAmount, char *strParam)
{
    char strCommand[256];
    sprintf (strCommand, 
             "$a=get-date '%s'; $a=$a.%s(%ld); $a=get-date $a -format '%s'; "
             "$a|out-file -encoding ascii -filepath %s;", 
             strDate, 
             strChange,
             iChangeAmount, 
             strFormat, 
             strFile);

    ShellExecuteA(NULL, "open", "powershell.exe", strCommand, "", "", 0);
    sleep(1000);  // Is enough of a delay for the command to complete - not dependable
    GetParamValue (strFile, strParam);
    return 0;
}

 Using CreateProcessA

• Creates a new process and its primary thread.
• The new process runs in the security context of the calling process.

GetNewDate_createprocess

typedef void *PVOID;
typedef PVOID HANDLE;
typedef struct _PROCESS_INFORMATION
{
	HANDLE hProcess;
	HANDLE hThread;
	DWORD dwProcessId;
	DWORD dwThreadId;
} PROCESS_INFORMATION;
	
typedef const char *LPTSTR;
typedef unsigned char far *LPBYTE;
	
typedef struct _STARTUPINFO {
  DWORD  cb;
  LPTSTR lpReserved;
  LPTSTR lpDesktop;
  LPTSTR lpTitle;
  DWORD  dwX;
  DWORD  dwY;
  DWORD  dwXSize;
  DWORD  dwYSize;
  DWORD  dwXCountChars;
  DWORD  dwYCountChars;
  DWORD  dwFillAttribute;
  DWORD  dwFlags;
  WORD   wShowWindow;
  WORD   cbReserved2;
  LPBYTE lpReserved2;
  HANDLE hStdInput;
  HANDLE hStdOutput;
  HANDLE hStdError;
} STARTUPINFO, *LPSTARTUPINFO;

PROCESS_INFORMATION pi = {0};
STARTUPINFO si = {0};

int GetNewDate_createprocess (char *strDate, char *strFormat, char *strFile,
                              char *strChange, int iChangeAmount, char *strParam)
{
    char strCommand[256];
    sprintf (strCommand, 
             "powershell \"$a=get-date '%s'; $a=$a.%s(%ld); $a=get-date $a -format '%s'; "
             "$a|out-file -encoding ascii -filepath %s;\"", 
             strDate, 
             strChange,
             iChangeAmount, 
             strFormat, 
             strFile);

    si.cb = sizeof(si);
    CreateProcessA (NULL, strCommand, NULL, NULL, FALSE, 0x08000000, NULL, NULL, &si, &pi);
    WaitForSingleObject (pi.hProcess, 10000);
    CloseHandle (pi.hProcess);
    CloseHandle (pi.hThread);
    GetParamValue (strFile, strParam);
    return 0;
}

 Calling Code

Calling Code

int iVuserId;
char strFile[100];
char *strDate   = "17-Aug-2012 06:49:41";
char *strFormat = "dd-MMM-yyyy HH:mm:ss";

lr_load_dll("shell32.dll");     // ShellExecuteA
lr_load_dll("kernel32.dll");    // CreateProcessA

// -------------------------------------------------------------------------
// Generate a unique file name for each vuser.  Used for output of the 
// powershell command.
// -------------------------------------------------------------------------

lr_whoami (&iVuserId, NULL, NULL);
if (iVuserId <= 0) { iVuserId = 1; }
sprintf (strFile, "d:\\dt-%03d.txt", iVuserId);

// -------------------------------------------------------------------------
// LoadRunner system command examples.
// -------------------------------------------------------------------------

GetNewDate_system (strDate, strFormat, strFile, "AddYears",   70, "pNewDate");
GetNewDate_system (strDate, strFormat, strFile, "AddMonths",  70, "pNewDate");
GetNewDate_system (strDate, strFormat, strFile, "AddDays",    70, "pNewDate");
GetNewDate_system (strDate, strFormat, strFile, "AddHours",   70, "pNewDate");
GetNewDate_system (strDate, strFormat, strFile, "AddMinutes", 70, "pNewDate");
GetNewDate_system (strDate, strFormat, strFile, "AddSeconds", 70, "pNewDate");

// -------------------------------------------------------------------------
// ShellExecute command examples.
// -------------------------------------------------------------------------

GetNewDate_shellexecute (strDate, strFormat, strFile, "AddYears",   70, "pNewDate");
GetNewDate_shellexecute (strDate, strFormat, strFile, "AddMonths",  70, "pNewDate");
GetNewDate_shellexecute (strDate, strFormat, strFile, "AddDays",    70, "pNewDate");
GetNewDate_shellexecute (strDate, strFormat, strFile, "AddHours",   70, "pNewDate");
GetNewDate_shellexecute (strDate, strFormat, strFile, "AddMinutes", 70, "pNewDate");
GetNewDate_shellexecute (strDate, strFormat, strFile, "AddSeconds", 70, "pNewDate");

// -------------------------------------------------------------------------
// CreateProcess command examples.
// -------------------------------------------------------------------------

GetNewDate_createprocess (strDate, strFormat, strFile, "AddYears",   70, "pNewDate");
GetNewDate_createprocess (strDate, strFormat, strFile, "AddMonths",  70, "pNewDate");
GetNewDate_createprocess (strDate, strFormat, strFile, "AddDays",    70, "pNewDate");
GetNewDate_createprocess (strDate, strFormat, strFile, "AddHours",   70, "pNewDate");
GetNewDate_createprocess (strDate, strFormat, strFile, "AddMinutes", 70, "pNewDate");
GetNewDate_createprocess (strDate, strFormat, strFile, "AddSeconds", 70, "pNewDate");

 Moving Forward

• Add error checking.
• Experiment with other Powershell commands using these techniques.
• Instead of writing output to a file, output to SQUID.
• Create a C/C# dll to handle date/time manipulations, call from within LoadRunner.

Comments

[CBA]

Excellent stuff. Just what I needed. You rock!