在LoadRunner中查找和替换字符串

参考《Search & Replace function for LoadRunner》：

http://ptfrontline.wordpress.com/2009/03/13/search-replace-function-for-lr/

LoadRunner中没有直接的函数支持查找并替换字符串，因此可以封装一个lr_replace函数出来：

// ----------------------------------------------------------------------------
//
// Description:
//    Search for and replace text within a string.
//
// Parameters:
//    src (in) - pointer to source string
//    from (in) - pointer to search text
//    to (in) - pointer to replacement text
//
// Returns:
//    Returns a pointer to dynamically-allocated memory containing string
//    with occurences of the text pointed to by 'from' replaced by with
//    the text pointed to by 'to'.
//
// Notes:
//    Do not use this directly in scripts unless you are a more advanced
//    user who knows C and string handling. See below for the function you
//    should use!
//
// ----------------------------------------------------------------------------
char *strReplace(const char *src, const char *from, const char *to)
{
  char *value;
  char *dst;
  char *match;
  int size;
  int fromlen;
  int tolen;

// Find out the lengths of the source string, text to replace, and
  // the replacement text.
  size = strlen(src) + 1;
  fromlen = strlen(from);
  tolen = strlen(to);

// Allocate the first chunk with enough for the original string.
  value = (char *)malloc(size);

// We need to return 'value', so let's make a copy to mess around with.
  dst = value;

// Before we begin, let's see if malloc was successful.
  if ( value != NULL )
  {
    // Loop until no matches are found.
    for ( ;; )
    {
      // Try to find the search text.
      match = (char *) strstr(src, from);
      if ( match != NULL )
      {
        // Found search text at location 'match'.
        // Find out how many characters to copy up to the 'match'.
        size_t count = match - src;

// We are going to realloc, and for that we will need a
        // temporary pointer for safe usage.
        char *temp;

// Calculate the total size the string will be after the
        // replacement is performed.
        size += tolen - fromlen;

// Attempt to realloc memory for the new size.
        //
        // temp = realloc(value, size);
        temp = (char *)realloc(value, size);

if ( temp == NULL )
        {
          // Attempt to realloc failed. Free the previously malloc'd
          // memory and return with our tail between our legs.
          free(value);
          return NULL;
        }

// The call to realloc was successful. But we'll want to
        // return 'value' eventually, so let's point it to the memory
        // that we are now working with. And let's not forget to point
        // to the right location in the destination as well.
        dst = temp + (dst - value);
        value = temp;

// Copy from the source to the point where we matched. Then
        // move the source pointer ahead by the amount we copied. And
        // move the destination pointer ahead by the same amount.
        memmove(dst, src, count);
        src += count;
        dst += count;

// Now copy in the replacement text 'to' at the position of
        // the match. Adjust the source pointer by the text we replaced.
        // Adjust the destination pointer by the amount of replacement
        // text.
        memmove(dst, to, tolen);
        src += fromlen;
        dst += tolen;
      }
      else // No match found.
      {
        // Copy any remaining part of the string. This includes the null
        // termination character.
        strcpy(dst, src);
        break;
      }
    } // For Loop()
  }
  return value;
}

// ----------------------------------------------------------------------------
//
// Description:
//    Find and replace text within a LoadRunner string.
//
// Parameters:
//    lrparam (in)    - pointer to LoadRunner Parameter Name
//    findstr (in)    - pointer to text top search for
//    replacestr (in) - pointer to text to use as replacement
//
// Returns:
//    Returns an integer. 0=Error, 1=Success.
//
// Example:
//    lr_save_string( "This is a small test of the search and replace function", "LRParam");
//    lr_replace( "LRParam", "a", "-x-" );
//    lr_output_message( "%s", lr_eval_string("{LRParam}") );
//
// ----------------------------------------------------------------------------
int lr_replace( const char *lrparam, char *findstr, char *replacestr )
{
  int res = 0;
  char *result_str;
  char lrp[1024];

// Finalize the LR Param Name
  sprintf( lrp, "{%s}", lrparam);

// Do the Search and Replace
  result_str = strReplace( lr_eval_string(lrp), findstr, replacestr );

// Process results
  if (result_str != NULL )
  {
    lr_save_string( result_str, lrparam );
    free( result_str );
    res = 1;
  }
  return res;
} // EOF

在脚本中引用包括上面代码的头文件“lr_replace.h”，使用lr_replace函数的例子如下所示：

#include "lr_replace.h"

Action()
{

// Store a string into "MyPar" parameter
lr_save_string("This is a string", "MyPar");

// For examples sake, convert it to URL encoded format
web_convert_param( "MyPar",
                   "SourceEncoding=PLAIN",
                   "TargetEncoding=URL", LAST);

// Output the current result
lr_output_message("%s", lr_eval_string("{MyPar}"));

// Replace the ? characters with %20
lr_replace("MyPar", "+", "%20" );

// Output new result
lr_output_message("%s", lr_eval_string("{MyPar}"));

return 0;
}