KSH: Loop through a double quoted comma separated variable

Question

Using KSH. I have a variable that contains strings enclosed in double quotes and separated by commas, I would like to loop through these strings, I do not want to recognise commas in the double quotes as separators.

I've tried setting IFS to IFS="\",\"" and IFS="," but it still recognises the comma inside the double quotes.

Simplified:

errorStrings="Some error","Another error","This, error"
oldIFS=$IFS
IFS=","
for error in $errorStrings;do
  echo "Checking for $error"
  #grep "$error" file >/dev/null 2>&1 && echo "$error found"
  continue
done
IFS=$oldIFS


Actual:
Checking for Some error
Checking for Another error
Checking for This
Checking for  error

Expected:
Checking for Some error
Checking for Another error
Checking for This, error

Answer 1

The first problem is that the errorStrings is not what you expect. Try

echo "e=[${errorStrings}]"

When you want the double quotes inside your string, use

errorStrings='"Some error","Another error","This, error"'

Your script will work better when you quote $errorStrings in the for-loop.

oldIFS=$IFS
IFS=","
for error in "$errorStrings";do
  echo "Checking for $error"
  #grep "$error" file >/dev/null 2>&1 && echo "$error found"
  continue
done
IFS=$oldIFS

This loop still has to be modified for deleting the quotes. Perhaps this is a good moment for using an array:

errorStrings=("Some error" "Another error" "This, error")
for error in "${errorStrings[@]}";do
  echo "Checking for $error"
  #grep "$error" file >/dev/null 2>&1 && echo "$error found"
  continue
done

I am not sure what options you have in your environment, perhaps this will work too:

errorStrings='"Some error","Another error","This, error"'

echo "${errorStrings}" | sed 's/","/"\n"/g' | while read error; do
   echo "Checking for $error"
done