LoadRunner：参数文件数据自动刷新及VuGen自动复制TXT数据插件求助

Hey there, let’s break down your two LoadRunner/VuGen challenges— I’ve spent plenty of time troubleshooting these exact scenarios, so here’s what I’ve learned:

1. Auto-refreshing Input Data in LoadRunner Parameter Files #

LoadRunner doesn’t have a native auto-refresh feature for parameter files, but you can implement this with a couple of reliable workarounds:

• Script-level parameter reloading with lr_load_parameter: If your data source is dynamic (like a frequently updated .txt file), add a custom block in your Vuser script to reload the parameter file at set intervals. For example:

  // Reload parameter file every 10 iterations to fetch fresh data
  if (lr_get_iteration() % 10 == 0) {
      lr_load_parameter("UserCredentials", "file=user_data.txt", "delimiter=,", "first_line=2");
      lr_output_message("Successfully reloaded parameter file at iteration %d", lr_get_iteration());
  }
  

  Just make sure the target .txt file isn’t locked by another process when LoadRunner attempts to read it.
• External scheduled script + LoadRunner auto-reload: Create a batch or PowerShell script that updates your parameter file (e.g., pulls fresh data from a backend source) and schedule it to run at your desired frequency. Then, in LoadRunner’s parameter properties, enable the Reload each iteration option under Data Handling— this ensures the script picks up the updated file content every time a new iteration starts.

2. VuGen Plugin for Auto-Copying Data from .txt Files #

Unfortunately, there’s no official or widely adopted VuGen plugin that handles automatic .txt data copying out of the box. But you can build a custom solution or use these practical workarounds:

• Custom C code in your Vuser script: Write a simple file I/O function to read directly from your .txt file and store the data in a LoadRunner parameter. Here’s a quick example:

  FILE *dataFile;
  char dataBuffer[2048];
  
  dataFile = fopen("source_data.txt", "r");
  if (dataFile != NULL) {
      fgets(dataBuffer, sizeof(dataBuffer), dataFile);
      lr_save_string(dataBuffer, "AutoCopiedData"); // Save to a reusable parameter
      fclose(dataFile);
  }
  

  This runs automatically every time your script executes, pulling the latest data without manual input.
• Leverage LoadRunner’s File Parameter type: If you just need to use the .txt data as a parameter, set up a File parameter and enable Reload each iteration. This will automatically fetch the latest version of the file content for each script run, no manual copy-paste needed.
• UI automation hack (for VuGen interface): If you need to copy data directly into VuGen’s UI (not just the script), use tools like AutoHotkey to write a small automation script that reads the .txt and pastes the data where needed. It’s not a native plugin, but it works for UI-focused tasks.

内容的提问来源于stack exchange，提问作者Sutapa