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

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