How can I loop thorough a record one character at a time?

Question

How can I loop thorough a record one character at a time? I want to interrogate records in a ASCII file one character at a time looking for and replacing non-printable characters. I tried using the Loop Condition with no luck. Thanks in advance for any help.

Answer 1

Yes, this is possible in a DataStage Transformer.

The "Loop Condition" creates a new output row per iteration. It operates on each row it receives. You might want to add a constraint to your output link which is only true when your loop iterations are finished (for that row).

A little pseudo-code to replace every 'ä' with a '?' by looping through char-by-char:

// Input Link "DSLink2" 
// provides a column named "text"


// Stage Variables:

NVarCHar(20) svLine := DSLink2.text
NChar(1)     svReplacementChar := "?"


// Loop Variables:

NChar(1)     lvCharToTest
Bit          lvCharOK := 0
NVarCHar(20) lvNewLine := ''
Integer      i := 0


// Loop Condition:

loop while (i < Len(svLine)) {
  i = i + 1
  lvCharToTest := svLine[i,1]

  // replace by proper test condition or function according to your needs:
  lvCharOK     := lvCharToTest = 'ä' 

  if (lvCharOK) {
    lvNewLine = lvNewLine + lvCharToTest
  }
  else {
    lvNewLine = lvNewLine + svReplacementChar
  }
}

// DSLink4_output:

If (i = Len(svLine)) {
  DSLInk4_output.text := lvNewLine
}

Screenshot of a Transformer Stage showing this example