how to find out if csv file fields are tab delimited or comma delimited

Question

how to find out if csv file fields are tab delimited or comma delimited. I need php validation for this. Can anyone plz help. Thanks in advance.

Answer 1

There is no 100% reliable way to detemine this. What you can do is

• If you have a method to validate the fields you read, try to read a few fields using either separator and validate against your method. If it breaks, use another one.
• Count the occurrence of tabs or commas in the file. Usually one is significantly higher than the other
• Last but not least: Ask the user, and allow him to override your guesses.

Answer 2

Aside from the trivial answer that c sv files are always comma-separated - it's in the name, I don't think you can come up with any hard rules. Both TSV and CSV files are sufficiently loosely specified that you can come up with files that would be acceptable as either.

A\tB,C
1,2\t3

(Assuming \t == TAB)

How would you decide whether this is TSV or CSV?

Answer 3

When I output a TSV file I author the tabs using \t the same method one would author a line break like \n so that being said I guess a method could be as follows:

<?php
$mysource = YOUR SOURCE HERE, file_get_contents() OR HOWEVER YOU WISH TO GET THE SOURCE;
 if(strpos($mysource, "\t") > 0){
   //We have a tab separator
 }else{
   // it might be CSV
 }
?>

I Guess this may not be the right manner, because you could have tabs and commas in the actual content as well. It's just an idea. Using regular expressions may be better, although I am not too clued up on that.